More module implementation partition units

36 files changed, 2521 insertions, 2101 deletions

diff --git a/server/.clang-format b/server/.clang-format
index 1755757..2ed05ee 100644
--- a/server/.clang-format
+++ b/server/.clang-format
@@ -132,7 +132,7 @@ BreakBeforeCloseBracketSwitch: false
 BreakBeforeConceptDeclarations: Always
 BreakBeforeBraces: Custom
 BreakBeforeInlineASMColon: OnlyMultiline
-BreakBeforeTemplateCloser: false
+BreakBeforeTemplateCloser: true
 BreakBeforeTernaryOperators: true
 BreakBinaryOperations: Never
 BreakConstructorInitializers: BeforeColon
diff --git a/server/CMakeLists.txt b/server/CMakeLists.txt
index df4eb90..15ebfae 100644
--- a/server/CMakeLists.txt
+++ b/server/CMakeLists.txt
@@ -30,26 +30,40 @@ target_sources(routemon_lib
     src/api.cppm
     src/api.cpp
     src/database.cppm
+    src/database.cpp
     src/config.cppm
     src/config.cpp
     src/datex2.cppm
+    src/datex2.cpp
     src/geo.cppm
+    src/geo.cpp
     src/gpx.cppm
     src/gpx.cpp
     src/http_client.cppm
+    src/http_client.cpp
     src/http_common.cppm
+    src/http_common.cpp
     src/http_server.cppm
+    src/http_server.cpp
     src/locale.cppm
+    src/locale.cpp
     src/log.cppm
+    src/log.cpp
     src/problem.cppm
-    src/req_ctx.cppm
+    src/problem.cpp
     src/routemon.cppm
     src/rwgps.cppm
+    src/rwgps.cpp
     src/sqlite3.cppm
+    src/sqlite3.cpp
     src/srv.cppm
+    src/srv.cpp
     src/time.cppm
+    src/time.cpp
     src/trace.cppm
+    src/trace.cpp
     src/util.cppm
+    src/util.cpp
     src/xml.cppm
     src/xml.cpp
 )
diff --git a/server/src/api.cpp b/server/src/api.cpp
index 9317f1b..e671f8a 100644
--- a/server/src/api.cpp
+++ b/server/src/api.cpp
@@ -5,15 +5,7 @@ module;
 
 module routemon:api$impl;
 
-import std;
 import :api;
-import :datex2;
-import :geo;
-import :gpx;
-import :log;
-import :req_ctx;
-import :time;
-import :trace;
 
 namespace {
 
@@ -255,8 +247,8 @@ auto handler::process_gpx(gpx::file&& gpx_file)
                                 | views::transform(
                                     [](auto const& lsp) -> geo::linestring
                                     { return *lsp; })
-                                | std::ranges::to<
-                                    std::vector<geo::linestring>>(),
+                                | std::ranges::
+                                    to<std::vector<geo::linestring>>(),
                           };
                         })
                     | std::ranges::to<std::vector<relevant_road_closure>>(),
diff --git a/server/src/api.cppm b/server/src/api.cppm
index 66e8f45..c93e65e 100644
--- a/server/src/api.cppm
+++ b/server/src/api.cppm
@@ -77,7 +77,8 @@ class handler
 {
   using lse_index_value = std::tuple<
       geo::box, std::shared_ptr<geo::linestring>,
-      std::shared_ptr<datex2::road_closure>>;
+      std::shared_ptr<datex2::road_closure>
+  >;
   using p_index_value =
       std::pair<geo::point, std::shared_ptr<datex2::road_closure>>;
   using lse_index =
diff --git a/server/src/database.cpp b/server/src/database.cpp
new file mode 100644
index 0000000..54e5f34
--- /dev/null
+++ b/server/src/database.cpp
@@ -0,0 +1,34 @@
+module routemon:database$impl;
+
+import :database;
+
+namespace routemon::database {
+
+constexpr std::int64_t expected_database_version = 1;
+
+auto open(std::string const& filename) -> std::shared_ptr<connection>
+{
+  auto dbc = sqlite3::open(filename);
+  try
+  {
+    auto version = std::optional<std::int64_t>{};
+    dbc.query("SELECT version FROM migration;").scan_single(version);
+    if (!version)
+      throw std::runtime_error{"failed to fetch database migration version"};
+    if (version != expected_database_version)
+    {
+      throw std::runtime_error{std::format(
+          "database migration version ({}) does not match expected "
+          "version ({}), consider running migrations",
+          *version, expected_database_version)};
+    }
+  }
+  catch (std::exception const& e)
+  {
+    throw std::runtime_error{std::format(
+        "failed to query database version: {}", e.what())};
+  }
+  return std::shared_ptr<connection>{new connection{std::move(dbc)}};
+}
+
+} // namespace routemon::database
diff --git a/server/src/database.cppm b/server/src/database.cppm
index 86ed0d7..ff5cae4 100644
--- a/server/src/database.cppm
+++ b/server/src/database.cppm
@@ -5,8 +5,6 @@ import :sqlite3;
 
 namespace routemon::database {
 
-static constexpr std::int64_t expected_database_version = 1;
-
 export class connection
 {
   sqlite3::connection dbc_;
@@ -19,29 +17,6 @@ public:
   // Nothing here yet
 };
 
-export auto open(std::string const& filename) -> std::shared_ptr<connection>
-{
-  auto dbc = sqlite3::open(filename);
-  try
-  {
-    auto version = std::optional<std::int64_t>{};
-    dbc.query("SELECT version FROM migration;").scan_single(version);
-    if (!version)
-      throw std::runtime_error{"failed to fetch database migration version"};
-    if (version != expected_database_version)
-    {
-      throw std::runtime_error{std::format(
-          "database migration version ({}) does not match expected "
-          "version ({}), consider running migrations",
-          *version, expected_database_version)};
-    }
-  }
-  catch (std::exception const& e)
-  {
-    throw std::runtime_error{std::format(
-        "failed to query database version: {}", e.what())};
-  }
-  return std::shared_ptr<connection>{new connection{std::move(dbc)}};
-}
+export auto open(std::string const& filename) -> std::shared_ptr<connection>;
 
 } // namespace routemon::database
diff --git a/server/src/datex2.cpp b/server/src/datex2.cpp
new file mode 100644
index 0000000..4c8000b
--- /dev/null
+++ b/server/src/datex2.cpp
@@ -0,0 +1,377 @@
+module;
+
+#include <boost/geometry/algorithms/is_empty.hpp>
+#include <boost/geometry/srs/epsg.hpp>
+#include <boost/geometry/srs/transformation.hpp>
+
+#include <pugixml.hpp>
+
+module routemon:datex2$impl;
+
+import :datex2;
+
+using namespace std::literals::string_view_literals;
+
+namespace routemon::datex2 {
+
+auto parse_timestamp(char const* in) -> std::optional<time::timestamp>
+{
+  auto res = time::timestamp{};
+  auto is = std::istringstream{in};
+  is >> std::chrono::parse("%Y-%m-%dT%H:%M:%SZ", res);
+  return is.fail() ? std::nullopt : std::make_optional(res);
+}
+
+auto loader::add_location_from_xml(
+    road_closure& rc, pugi::xml_node const& loc_xml) -> void
+{
+  auto loc_xml_type = std::string_view{loc_xml.attribute("xsi:type").value()};
+  if (loc_xml_type == "loc:ItineraryByIndexedLocations")
+  {
+    for (auto const loc_cont_xml :
+         loc_xml.children("loc:locationContainedInItinerary"))
+    {
+      add_location_from_xml(rc, loc_cont_xml.child("loc:location"));
+    }
+  }
+  else if (loc_xml_type == "loc:LinearLocation"
+           || loc_xml_type == "loc:SingleRoadLinearLocation")
+  {
+    auto const& loc_gml_xml = loc_xml.child("loc:gmlLineString");
+    if (!loc_gml_xml)
+      return;
+
+    auto const srs_name =
+        std::string_view{loc_gml_xml.attribute("srsName").value()};
+    if (srs_name != "WGS 84"sv)
+    {
+      warnings_.insert(
+          std::format("don't now how to handle the CRS {}", srs_name));
+      return;
+    }
+    auto const pos_list_str =
+        std::string_view{loc_gml_xml.child_value("loc:posList")};
+    // lat1 long1 lat2 long2 ... lat(n-1) long(n-1) latn longn
+
+    auto ls = std::make_shared<geo::linestring>();
+
+    auto lat_set = false;
+    auto lat = 0.0;
+    for (auto const lat_or_long_str : std::views::split(pos_list_str, " "sv))
+    {
+      auto mlat_or_long = util::parse_double(std::string_view{lat_or_long_str});
+      if (!mlat_or_long)
+      {
+        warnings_.insert(
+            std::format(
+                "failed to parse coordinate {:?}",
+                std::string_view{lat_or_long_str}));
+        return;
+      }
+
+      if (!lat_set)
+      {
+        lat = *mlat_or_long;
+        lat_set = true;
+      }
+      else
+      {
+        bgeo::append(*ls, geo::point{*mlat_or_long, lat});
+        lat = 0;
+        lat_set = false;
+      }
+    }
+
+    if (bgeo::is_empty(*ls))
+    {
+      warnings_.emplace("empty line string in data set");
+      return;
+    }
+
+    rc.relevant_line_strings.push_back(ls);
+  }
+  else if (loc_xml_type == "loc:PointLocation")
+  {
+    auto const& coords_xml =
+        loc_xml.child("loc:pointByCoordinates").child("loc:pointCoordinates");
+    if (!coords_xml)
+      return;
+
+    auto mlat = util::parse_double(coords_xml.child_value("loc:latitude"));
+    auto mlon = util::parse_double(coords_xml.child_value("loc:longitude"));
+    if (!mlat || !mlon)
+    {
+      warnings_.emplace("failed to parse PointLocation coordinates");
+      return;
+    }
+
+    // Vaag genoeg zegt NDW dat het hier om WGS 84 gaat:
+    //   https://docs.ndw.nu/en/dataformaten/datex2-v3/elementen/locationreferencing/pointCoordinates/
+    // maar heeft het UML-model van DATEX II v3 het over ETRS 89:
+    //   https://docs.datex2.eu/_static/data/v3.7/umlmodel/html/EARoot/EA3/EA3/EA5/EA676.htm
+
+    auto const coords_etrs89 = geo::point{*mlon, *mlat};
+    auto coords_wgs84 = geo::point{};
+    etrs89_to_wgs84_.forward(coords_etrs89, coords_wgs84);
+
+    rc.relevant_points.push_back(coords_wgs84);
+  }
+  else
+  {
+    warnings_.insert(
+        std::format(
+            "don't know how to hande location of type {}, ignoring",
+            loc_xml.attribute("xsi:type").value()));
+    return;
+  }
+}
+
+auto loader::handle_road_or_carriageway_or_lane_management(
+    pugi::xml_node const& record_xml, std::weak_ptr<situation> parent)
+    -> std::optional<std::shared_ptr<road_closure>>
+{
+  auto const type = std::string_view{
+    record_xml.child("sit:roadOrCarriagewayOrLaneManagementType").child_value()
+  };
+  if (type != "carriagewayClosures" && type != "roadClosed")
+    // TODO: checken of er nog andere types fietsers de doorgang zouden
+    // kunnen blokkeren?
+    return std::nullopt;
+
+  auto const& restricted_vehicle_types_xml =
+      record_xml.child("sit:forVehiclesWithCharacteristicsOf");
+  bool likely_restriction_for_bikes = restricted_vehicle_types_xml.empty();
+  for (auto const vehicle_type_xml :
+       restricted_vehicle_types_xml.children("com:vehicleType"))
+  {
+    auto vehicle_type = std::string_view{vehicle_type_xml.child_value()};
+    if (vehicle_type == "anyVehicle" || vehicle_type == "bicycle"
+        || vehicle_type == "unknown" || vehicle_type == "other")
+    {
+      likely_restriction_for_bikes = true;
+    }
+  }
+  if (!likely_restriction_for_bikes)
+    return std::nullopt;
+
+  //---- Check if within the defined validity period
+
+  auto validity = std::optional<time::period_seq>{};
+  auto const& validity_xml = record_xml.child("sit:validity");
+  if (validity_xml
+      && validity_xml.child_value("com:validityStatus")
+             == "definedByValidityTimeSpec"sv)
+  {
+    auto const& validity_spec_xml =
+        validity_xml.child("com:validityTimeSpecification");
+
+    auto valid_periods = std::vector<time::period>{};
+    auto exception_periods = std::vector<time::period>{};
+
+    // TODO: com:overallEndTime may be missing (according to the DATEX
+    // II v3 data model)
+    auto const overall_start_time =
+        parse_timestamp(validity_spec_xml.child_value("com:overallStartTime"));
+    auto const overall_end_time =
+        parse_timestamp(validity_spec_xml.child_value("com:overallEndTime"));
+    if (overall_start_time && overall_end_time
+        && *overall_start_time < *overall_end_time)
+    {
+      valid_periods.emplace_back(*overall_start_time, *overall_end_time);
+
+      for (auto const valid_period_xml :
+           validity_xml.children("com:validPeriod"))
+      {
+        auto const start_of_period =
+            parse_timestamp(valid_period_xml.child_value("com:startOfPeriod"));
+        auto const end_of_period =
+            parse_timestamp(valid_period_xml.child_value("com:endOfPeriod"));
+        if (start_of_period && end_of_period
+            && *start_of_period < *end_of_period)
+        {
+          valid_periods.emplace_back(*start_of_period, *end_of_period);
+        }
+      }
+      for (auto const exception_period_xml :
+           validity_xml.children("com:exceptionPeriod"))
+      {
+        auto const start_of_period = parse_timestamp(
+            exception_period_xml.child_value("com:startOfPeriod"));
+        auto const end_of_period = parse_timestamp(
+            exception_period_xml.child_value("com:endOfPeriod"));
+        if (start_of_period && end_of_period
+            && *start_of_period < *end_of_period)
+        {
+          exception_periods.emplace_back(*start_of_period, *end_of_period);
+        }
+      }
+
+      validity =
+          time::period_seq{valid_periods.begin(), valid_periods.end()}.except(
+              time::period_seq{
+                exception_periods.begin(), exception_periods.end()
+              });
+    }
+    else
+    {
+      warnings_.insert(
+          std::format(
+              "invalid overall start / end time (start time: {}, end "
+              "time: {})",
+              validity_spec_xml.child_value("com:overallStartTime"),
+              validity_spec_xml.child_value("com:overallEndTime")));
+      return std::nullopt;
+    }
+  }
+
+  //---- Try to extract the location info
+
+  auto rc = std::make_shared<road_closure>(std::move(parent), validity);
+  add_location_from_xml(*rc, record_xml.child("sit:locationReference"));
+  return rc;
+}
+
+auto loader::load_situation_publication(std::string const& filename)
+    -> situation_publication
+{
+  auto doc = pugi::xml_document{};
+  if (auto result = doc.load_file(filename.c_str()); !result)
+  {
+    throw std::runtime_error{result.description()};
+  }
+  auto payload_xml = doc.child("mc:messageContainer").child("mc:payload");
+  auto mpublication_time =
+      parse_timestamp(payload_xml.child_value("com:publicationTime"));
+  if (!mpublication_time)
+    throw std::runtime_error{
+      "provided publication does not name publication time"
+    };
+
+  auto situations = std::vector<std::shared_ptr<situation>>{};
+  for (auto const sit_xml : payload_xml.children("sit:situation"))
+  {
+    auto id = std::string_view{sit_xml.attribute("id").value()};
+
+    auto const sit = std::make_shared<situation>(std::string{id});
+    situations.push_back(sit);
+
+    auto const& header_info_xml = sit_xml.child("sit:headerInformation");
+    if (header_info_xml.child_value("com:informationStatus") != "real"sv)
+      continue;
+
+    for (auto const record_xml : sit_xml.children("sit:situationRecord"))
+    {
+      auto const record_type =
+          std::string_view{record_xml.attribute("xsi:type").value()};
+      auto const primary_record_types = std::unordered_set<std::string_view>{
+        "sit:Roadworks",
+        /* { */ "sit:MaintenanceWorks",
+        /* | */ "sit:ConstructionWorks",
+        /* } */
+        "sit:Obstruction",
+        /* { */ "sit:EnvironmentalObstruction",
+        /* | */ "sit:GeneralObstruction",
+        /* | */ "sit:InfrastructureDamageObstruction",
+        /* } */
+        "sit:Activity",
+        /* { */ "sit:PublicEvent",
+        /* } */
+      };
+
+      if (record_type == "sit:RoadOrCarriagewayOrLaneManagement")
+      {
+        if (auto rc =
+                handle_road_or_carriageway_or_lane_management(record_xml, sit))
+        {
+          sit->road_closures.push_back(*rc);
+        }
+      }
+      else if (primary_record_types.contains(record_type))
+      {
+        for (auto const comment_xml :
+             record_xml.children("sit:generalPublicComment"))
+        {
+          //            if
+          //            (comment_xml.child_value("sit:commentType")
+          //            == "internalNote"sv) {
+          auto candidate = std::optional<
+              std::pair<std::string_view, std::string_view>
+          >{}; // (text, language)
+          for (auto const comment_value_xml : comment_xml.child("sit:comment")
+                                                  .child("com:values")
+                                                  .children("com:value"))
+          {
+            if (!candidate
+                || comment_value_xml.attribute("lang").value() == "nl"sv
+                || (candidate->second != "nl"sv
+                    && comment_value_xml.attribute("lang").value() == "nl"sv))
+            {
+              candidate = std::make_pair(
+                  comment_value_xml.child_value(),
+                  comment_value_xml.attribute("lang").value());
+            }
+          }
+          if (candidate)
+          {
+            auto already_present = false;
+            for (auto const& comment : sit->comments)
+              already_present = already_present || comment == candidate->first;
+            if (!already_present)
+            {
+              sit->comments.emplace_back(candidate->first);
+            }
+          }
+          //            }
+        }
+
+        if (auto const location_ref_xml =
+                record_xml.child("sit:locationReference"))
+        {
+          if (location_ref_xml.attribute("xsi:type").value()
+              == "loc:PointLocation"sv)
+          {
+            if (auto const coords_xml =
+                    location_ref_xml.child("loc:pointByCoordinates")
+                        .child("loc:pointCoordinates"))
+            {
+              auto const mlat =
+                  util::parse_double(coords_xml.child_value("loc:latitude"));
+              auto const mlon =
+                  util::parse_double(coords_xml.child_value("loc:longitude"));
+              if (mlat && mlon)
+              {
+                // Vaag genoeg zegt NDW dat het hier om WGS
+                // 84 gaat:
+                //   https://docs.ndw.nu/en/dataformaten/datex2-v3/elementen/locationreferencing/pointCoordinates/
+                // maar heeft het UML-model van DATEX II v3
+                // het over ETRS 89:
+                //   https://docs.datex2.eu/_static/data/v3.7/umlmodel/html/EARoot/EA3/EA3/EA5/EA676.htm
+
+                auto const coords_etrs89 = geo::point{*mlon, *mlat};
+                auto coords_wgs84 = geo::point{};
+                etrs89_to_wgs84_.forward(coords_etrs89, coords_wgs84);
+
+                if (!sit->location)
+                {
+                  sit->location = coords_wgs84;
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+
+  return {
+    .publication_time = *mpublication_time,
+    .situations = situations,
+  };
+}
+
+auto loader::warnings() const -> std::multiset<std::string> const&
+{
+  return warnings_;
+}
+
+} // namespace routemon::datex2
diff --git a/server/src/datex2.cppm b/server/src/datex2.cppm
index d7b4921..9c75013 100644
--- a/server/src/datex2.cppm
+++ b/server/src/datex2.cppm
@@ -42,377 +42,26 @@ export struct situation_publication
   std::vector<std::shared_ptr<situation>> situations;
 };
 
-auto parse_timestamp(char const* in) -> std::optional<time::timestamp>
-{
-  auto res = time::timestamp{};
-  auto is = std::istringstream{in};
-  is >> std::chrono::parse("%Y-%m-%dT%H:%M:%SZ", res);
-  return is.fail() ? std::nullopt : std::make_optional(res);
-}
-
 export class loader
 {
   // ETRS 89 (EPSG:4258) -> WGS 84 (EPSG:4326)
-  bgeo::srs::transformation<
-      bgeo::srs::static_epsg<4258>, bgeo::srs::static_epsg<4326>>
-      etrs89_to_wgs84_{};
+  bgeo::srs::
+      transformation<bgeo::srs::static_epsg<4258>, bgeo::srs::static_epsg<4326>>
+          etrs89_to_wgs84_{};
 
   std::multiset<std::string> warnings_;
 
   auto add_location_from_xml(road_closure& rc, pugi::xml_node const& loc_xml)
-      -> void
-  {
-    auto loc_xml_type = std::string_view{loc_xml.attribute("xsi:type").value()};
-    if (loc_xml_type == "loc:ItineraryByIndexedLocations")
-    {
-      for (auto const loc_cont_xml :
-           loc_xml.children("loc:locationContainedInItinerary"))
-      {
-        add_location_from_xml(rc, loc_cont_xml.child("loc:location"));
-      }
-    }
-    else if (loc_xml_type == "loc:LinearLocation"
-             || loc_xml_type == "loc:SingleRoadLinearLocation")
-    {
-      auto const& loc_gml_xml = loc_xml.child("loc:gmlLineString");
-      if (!loc_gml_xml)
-        return;
-
-      auto const srs_name =
-          std::string_view{loc_gml_xml.attribute("srsName").value()};
-      if (srs_name != "WGS 84"sv)
-      {
-        warnings_.insert(
-            std::format("don't now how to handle the CRS {}", srs_name));
-        return;
-      }
-      auto const pos_list_str =
-          std::string_view{loc_gml_xml.child_value("loc:posList")};
-      // lat1 long1 lat2 long2 ... lat(n-1) long(n-1) latn longn
-
-      auto ls = std::make_shared<geo::linestring>();
-
-      auto lat_set = false;
-      auto lat = 0.0;
-      for (auto const lat_or_long_str : std::views::split(pos_list_str, " "sv))
-      {
-        auto mlat_or_long =
-            util::parse_double(std::string_view{lat_or_long_str});
-        if (!mlat_or_long)
-        {
-          warnings_.insert(
-              std::format(
-                  "failed to parse coordinate {:?}",
-                  std::string_view{lat_or_long_str}));
-          return;
-        }
-
-        if (!lat_set)
-        {
-          lat = *mlat_or_long;
-          lat_set = true;
-        }
-        else
-        {
-          bgeo::append(*ls, geo::point{*mlat_or_long, lat});
-          lat = 0;
-          lat_set = false;
-        }
-      }
-
-      if (bgeo::is_empty(*ls))
-      {
-        warnings_.emplace("empty line string in data set");
-        return;
-      }
-
-      rc.relevant_line_strings.push_back(ls);
-    }
-    else if (loc_xml_type == "loc:PointLocation")
-    {
-      auto const& coords_xml =
-          loc_xml.child("loc:pointByCoordinates").child("loc:pointCoordinates");
-      if (!coords_xml)
-        return;
-
-      auto mlat = util::parse_double(coords_xml.child_value("loc:latitude"));
-      auto mlon = util::parse_double(coords_xml.child_value("loc:longitude"));
-      if (!mlat || !mlon)
-      {
-        warnings_.emplace("failed to parse PointLocation coordinates");
-        return;
-      }
-
-      // Vaag genoeg zegt NDW dat het hier om WGS 84 gaat:
-      //   https://docs.ndw.nu/en/dataformaten/datex2-v3/elementen/locationreferencing/pointCoordinates/
-      // maar heeft het UML-model van DATEX II v3 het over ETRS 89:
-      //   https://docs.datex2.eu/_static/data/v3.7/umlmodel/html/EARoot/EA3/EA3/EA5/EA676.htm
-
-      auto const coords_etrs89 = geo::point{*mlon, *mlat};
-      auto coords_wgs84 = geo::point{};
-      etrs89_to_wgs84_.forward(coords_etrs89, coords_wgs84);
-
-      rc.relevant_points.push_back(coords_wgs84);
-    }
-    else
-    {
-      warnings_.insert(
-          std::format(
-              "don't know how to hande location of type {}, ignoring",
-              loc_xml.attribute("xsi:type").value()));
-      return;
-    }
-  }
+      -> void;
 
   auto handle_road_or_carriageway_or_lane_management(
       pugi::xml_node const& record_xml, std::weak_ptr<situation> parent)
-      -> std::optional<std::shared_ptr<road_closure>>
-  {
-    auto const type =
-        std::string_view{record_xml
-                             .child("sit:roadOrCarriagewayOrLaneManagementType")
-                             .child_value()};
-    if (type != "carriagewayClosures" && type != "roadClosed")
-      // TODO: checken of er nog andere types fietsers de doorgang zouden
-      // kunnen blokkeren?
-      return std::nullopt;
-
-    auto const& restricted_vehicle_types_xml =
-        record_xml.child("sit:forVehiclesWithCharacteristicsOf");
-    bool likely_restriction_for_bikes = restricted_vehicle_types_xml.empty();
-    for (auto const vehicle_type_xml :
-         restricted_vehicle_types_xml.children("com:vehicleType"))
-    {
-      auto vehicle_type = std::string_view{vehicle_type_xml.child_value()};
-      if (vehicle_type == "anyVehicle" || vehicle_type == "bicycle"
-          || vehicle_type == "unknown" || vehicle_type == "other")
-      {
-        likely_restriction_for_bikes = true;
-      }
-    }
-    if (!likely_restriction_for_bikes)
-      return std::nullopt;
-
-    //---- Check if within the defined validity period
-
-    auto validity = std::optional<time::period_seq>{};
-    auto const& validity_xml = record_xml.child("sit:validity");
-    if (validity_xml
-        && validity_xml.child_value("com:validityStatus")
-               == "definedByValidityTimeSpec"sv)
-    {
-      auto const& validity_spec_xml =
-          validity_xml.child("com:validityTimeSpecification");
-
-      auto valid_periods = std::vector<time::period>{};
-      auto exception_periods = std::vector<time::period>{};
-
-      // TODO: com:overallEndTime may be missing (according to the DATEX
-      // II v3 data model)
-      auto const overall_start_time = parse_timestamp(
-          validity_spec_xml.child_value("com:overallStartTime"));
-      auto const overall_end_time =
-          parse_timestamp(validity_spec_xml.child_value("com:overallEndTime"));
-      if (overall_start_time && overall_end_time
-          && *overall_start_time < *overall_end_time)
-      {
-        valid_periods.emplace_back(*overall_start_time, *overall_end_time);
-
-        for (auto const valid_period_xml :
-             validity_xml.children("com:validPeriod"))
-        {
-          auto const start_of_period = parse_timestamp(
-              valid_period_xml.child_value("com:startOfPeriod"));
-          auto const end_of_period =
-              parse_timestamp(valid_period_xml.child_value("com:endOfPeriod"));
-          if (start_of_period && end_of_period
-              && *start_of_period < *end_of_period)
-          {
-            valid_periods.emplace_back(*start_of_period, *end_of_period);
-          }
-        }
-        for (auto const exception_period_xml :
-             validity_xml.children("com:exceptionPeriod"))
-        {
-          auto const start_of_period = parse_timestamp(
-              exception_period_xml.child_value("com:startOfPeriod"));
-          auto const end_of_period = parse_timestamp(
-              exception_period_xml.child_value("com:endOfPeriod"));
-          if (start_of_period && end_of_period
-              && *start_of_period < *end_of_period)
-          {
-            exception_periods.emplace_back(*start_of_period, *end_of_period);
-          }
-        }
-
-        validity =
-            time::period_seq{valid_periods.begin(), valid_periods.end()}.except(
-                time::period_seq{
-                  exception_periods.begin(), exception_periods.end()
-                });
-      }
-      else
-      {
-        warnings_.insert(
-            std::format(
-                "invalid overall start / end time (start time: {}, end "
-                "time: {})",
-                validity_spec_xml.child_value("com:overallStartTime"),
-                validity_spec_xml.child_value("com:overallEndTime")));
-        return std::nullopt;
-      }
-    }
-
-    //---- Try to extract the location info
-
-    auto rc = std::make_shared<road_closure>(std::move(parent), validity);
-    add_location_from_xml(*rc, record_xml.child("sit:locationReference"));
-    return rc;
-  }
+      -> std::optional<std::shared_ptr<road_closure>>;
 
 public:
   [[nodiscard]] auto load_situation_publication(std::string const& filename)
-      -> situation_publication
-  {
-    auto doc = pugi::xml_document{};
-    if (auto result = doc.load_file(filename.c_str()); !result)
-    {
-      throw std::runtime_error{result.description()};
-    }
-    auto payload_xml = doc.child("mc:messageContainer").child("mc:payload");
-    auto mpublication_time =
-        parse_timestamp(payload_xml.child_value("com:publicationTime"));
-    if (!mpublication_time)
-      throw std::runtime_error{
-        "provided publication does not name publication time"
-      };
-
-    auto situations = std::vector<std::shared_ptr<situation>>{};
-    for (auto const sit_xml : payload_xml.children("sit:situation"))
-    {
-      auto id = std::string_view{sit_xml.attribute("id").value()};
-
-      auto const sit = std::make_shared<situation>(std::string{id});
-      situations.push_back(sit);
-
-      auto const& header_info_xml = sit_xml.child("sit:headerInformation");
-      if (header_info_xml.child_value("com:informationStatus") != "real"sv)
-        continue;
-
-      for (auto const record_xml : sit_xml.children("sit:situationRecord"))
-      {
-        auto const record_type =
-            std::string_view{record_xml.attribute("xsi:type").value()};
-        auto const primary_record_types = std::unordered_set<std::string_view>{
-          "sit:Roadworks",
-          /* { */ "sit:MaintenanceWorks",
-          /* | */ "sit:ConstructionWorks",
-          /* } */
-          "sit:Obstruction",
-          /* { */ "sit:EnvironmentalObstruction",
-          /* | */ "sit:GeneralObstruction",
-          /* | */ "sit:InfrastructureDamageObstruction",
-          /* } */
-          "sit:Activity",
-          /* { */ "sit:PublicEvent",
-          /* } */
-        };
-
-        if (record_type == "sit:RoadOrCarriagewayOrLaneManagement")
-        {
-          if (auto rc = handle_road_or_carriageway_or_lane_management(
-                  record_xml, sit))
-          {
-            sit->road_closures.push_back(*rc);
-          }
-        }
-        else if (primary_record_types.contains(record_type))
-        {
-          for (auto const comment_xml :
-               record_xml.children("sit:generalPublicComment"))
-          {
-            //            if
-            //            (comment_xml.child_value("sit:commentType")
-            //            == "internalNote"sv) {
-            auto candidate = std::optional<std::pair<
-                std::string_view, std::string_view>>{}; // (text, language)
-            for (auto const comment_value_xml : comment_xml.child("sit:comment")
-                                                    .child("com:values")
-                                                    .children("com:value"))
-            {
-              if (!candidate
-                  || comment_value_xml.attribute("lang").value() == "nl"sv
-                  || (candidate->second != "nl"sv
-                      && comment_value_xml.attribute("lang").value() == "nl"sv))
-              {
-                candidate = std::make_pair(
-                    comment_value_xml.child_value(),
-                    comment_value_xml.attribute("lang").value());
-              }
-            }
-            if (candidate)
-            {
-              auto already_present = false;
-              for (auto const& comment : sit->comments)
-                already_present =
-                    already_present || comment == candidate->first;
-              if (!already_present)
-              {
-                sit->comments.emplace_back(candidate->first);
-              }
-            }
-            //            }
-          }
-
-          if (auto const location_ref_xml =
-                  record_xml.child("sit:locationReference"))
-          {
-            if (location_ref_xml.attribute("xsi:type").value()
-                == "loc:PointLocation"sv)
-            {
-              if (auto const coords_xml =
-                      location_ref_xml.child("loc:pointByCoordinates")
-                          .child("loc:pointCoordinates"))
-              {
-                auto const mlat =
-                    util::parse_double(coords_xml.child_value("loc:latitude"));
-                auto const mlon =
-                    util::parse_double(coords_xml.child_value("loc:longitude"));
-                if (mlat && mlon)
-                {
-                  // Vaag genoeg zegt NDW dat het hier om WGS
-                  // 84 gaat:
-                  //   https://docs.ndw.nu/en/dataformaten/datex2-v3/elementen/locationreferencing/pointCoordinates/
-                  // maar heeft het UML-model van DATEX II v3
-                  // het over ETRS 89:
-                  //   https://docs.datex2.eu/_static/data/v3.7/umlmodel/html/EARoot/EA3/EA3/EA5/EA676.htm
-
-                  auto const coords_etrs89 = geo::point{*mlon, *mlat};
-                  auto coords_wgs84 = geo::point{};
-                  etrs89_to_wgs84_.forward(coords_etrs89, coords_wgs84);
-
-                  if (!sit->location)
-                  {
-                    sit->location = coords_wgs84;
-                  }
-                }
-              }
-            }
-          }
-        }
-      }
-    }
-
-    return {
-      .publication_time = *mpublication_time,
-      .situations = situations,
-    };
-  }
-
-  [[nodiscard]] auto warnings() const -> std::multiset<std::string> const&
-  {
-    return warnings_;
-  }
+      -> situation_publication;
+  [[nodiscard]] auto warnings() const -> std::multiset<std::string> const&;
 };
 
 } // namespace routemon::datex2
diff --git a/server/src/geo.cpp b/server/src/geo.cpp
new file mode 100644
index 0000000..1776f3c
--- /dev/null
+++ b/server/src/geo.cpp
@@ -0,0 +1,42 @@
+module;
+
+#include <boost/geometry.hpp>
+
+module routemon:geo$impl;
+
+import :geo;
+
+namespace routemon::geo {
+
+auto split_linestring_with_overlap_segments(
+    linestring const& ls, double max_split_distance_m,
+    std::vector<linestring>& append_to) -> void
+{
+  if (bgeo::is_empty(ls))
+    return;
+
+  auto current_ls = linestring{};
+  auto current_ls_length = 0.0;
+  auto previous = std::optional<point>{};
+  bgeo::for_each_point(
+      ls,
+      [&](point p) -> void
+      {
+        bgeo::append(current_ls, p);
+        if (previous)
+        {
+          auto d = bgeo::distance(*previous, p, vincenty_strategy());
+          current_ls_length += d;
+          if (current_ls_length > max_split_distance_m)
+          {
+            append_to.push_back(std::move(current_ls));
+            current_ls = linestring{*previous, p};
+            current_ls_length = d;
+          }
+        }
+        previous = p;
+      });
+  append_to.emplace_back(std::move(current_ls));
+}
+
+} // namespace routemon::geo
diff --git a/server/src/geo.cppm b/server/src/geo.cppm
index b599ad4..4f8b840 100644
--- a/server/src/geo.cppm
+++ b/server/src/geo.cppm
@@ -17,33 +17,6 @@ using vincenty_strategy = bgeo::strategy::distance::vincenty<stype>;
 
 auto split_linestring_with_overlap_segments(
     linestring const& ls, double max_split_distance_m,
-    std::vector<linestring>& append_to) -> void
-{
-  if (bgeo::is_empty(ls))
-    return;
-
-  auto current_ls = linestring{};
-  auto current_ls_length = 0.0;
-  auto previous = std::optional<point>{};
-  bgeo::for_each_point(
-      ls,
-      [&](point p) -> void
-      {
-        bgeo::append(current_ls, p);
-        if (previous)
-        {
-          auto d = bgeo::distance(*previous, p, vincenty_strategy());
-          current_ls_length += d;
-          if (current_ls_length > max_split_distance_m)
-          {
-            append_to.push_back(std::move(current_ls));
-            current_ls = linestring{*previous, p};
-            current_ls_length = d;
-          }
-        }
-        previous = p;
-      });
-  append_to.emplace_back(std::move(current_ls));
-}
+    std::vector<linestring>& append_to) -> void;
 
 } // namespace routemon::geo
diff --git a/server/src/http_client.cpp b/server/src/http_client.cpp
new file mode 100644
index 0000000..0f3d9e6
--- /dev/null
+++ b/server/src/http_client.cpp
@@ -0,0 +1,20 @@
+module;
+
+#include <boost/asio/ssl.hpp>
+#include <boost/beast/core.hpp>
+#include <boost/beast/http.hpp>
+
+module routemon:http.client$impl;
+
+import :http.client;
+
+namespace routemon::http {
+
+client::client(net::io_context& ioc) : ioc_{ioc}, resolver_{ioc}
+{
+  sslc_.set_default_verify_paths();
+  sslc_.set_verify_mode(
+      net::ssl::verify_peer | net::ssl::verify_fail_if_no_peer_cert);
+}
+
+} // namespace routemon::http
diff --git a/server/src/http_client.cppm b/server/src/http_client.cppm
index bea5384..2047b01 100644
--- a/server/src/http_client.cppm
+++ b/server/src/http_client.cppm
@@ -23,17 +23,15 @@ export class client
   tcp::resolver resolver_;
 
 public:
-  explicit client(net::io_context& ioc) : ioc_{ioc}, resolver_{ioc}
-  {
-    sslc_.set_default_verify_paths();
-    sslc_.set_verify_mode(
-        net::ssl::verify_peer | net::ssl::verify_fail_if_no_peer_cert);
-  }
+  explicit client(net::io_context& ioc);
 
   template <class ReqBody>
   auto do_request(bhttp::request<ReqBody>& req)
       -> bhttp::response<bhttp::dynamic_body>
   {
+    // TODO: call into non-template member ASAP.
+    // Consider using beast::message_generator.
+
     auto stream = ssl::stream<beast::tcp_stream>{ioc_, sslc_};
 
     auto host = std::string{req.at(bhttp::field::host)};
diff --git a/server/src/http_common.cpp b/server/src/http_common.cpp
new file mode 100644
index 0000000..1c60d60
--- /dev/null
+++ b/server/src/http_common.cpp
@@ -0,0 +1,108 @@
+module;
+
+#include <boost/beast/core.hpp>
+#include <boost/beast/http.hpp>
+
+module routemon:http.common$impl;
+
+import :http.common;
+
+namespace routemon::http {
+
+supported_verb::supported_verb(supported_verb_t value) : value{value} {}
+
+auto supported_verb::from(bhttp::verb v) -> std::optional<supported_verb>
+{
+  switch (v)
+  {
+  case bhttp::verb::options:
+    return supported_verb::options;
+  case bhttp::verb::delete_:
+    return supported_verb::delete_;
+  case bhttp::verb::get:
+    return supported_verb::get;
+  case bhttp::verb::head:
+    return supported_verb::head;
+  case bhttp::verb::post:
+    return supported_verb::post;
+  case bhttp::verb::put:
+    return supported_verb::put;
+  default:
+    return std::nullopt;
+  }
+}
+
+supported_verb::operator bhttp::verb() const
+{
+  switch (value)
+  {
+  case supported_verb::options:
+    return bhttp::verb::options;
+  case supported_verb::delete_:
+    return bhttp::verb::delete_;
+  case supported_verb::get:
+    return bhttp::verb::get;
+  case supported_verb::head:
+    return bhttp::verb::head;
+  case supported_verb::post:
+    return bhttp::verb::post;
+  case supported_verb::put:
+    return bhttp::verb::put;
+  }
+}
+
+auto verb_set::with(supported_verb v) const noexcept -> verb_set
+{
+  auto set = verb_set{*this};
+  switch (v.value)
+  {
+  case supported_verb::delete_:
+    set.delete_ = true;
+    return set;
+  case supported_verb::get:
+    set.get = true;
+    return set;
+  case supported_verb::head:
+    set.head = true;
+    return set;
+  case supported_verb::post:
+    set.post = true;
+    return set;
+  case supported_verb::put:
+    set.put = true;
+    return set;
+  case supported_verb::options:
+    set.options = true;
+    return set;
+  }
+}
+
+auto verb_set::empty() const noexcept -> bool { return *this == verb_set{}; }
+
+auto verb_set::to_string() const -> std::string
+{
+  std::ostringstream ss;
+  bool wrote = false;
+  auto write = [&](bhttp::verb v)
+  {
+    if (wrote)
+      ss << ", ";
+    ss << v;
+    wrote = true;
+  };
+  if (delete_)
+    write(bhttp::verb::delete_);
+  if (get)
+    write(bhttp::verb::get);
+  if (head)
+    write(bhttp::verb::head);
+  if (post)
+    write(bhttp::verb::post);
+  if (put)
+    write(bhttp::verb::put);
+  if (options)
+    write(bhttp::verb::options);
+  return ss.str();
+}
+
+} // namespace routemon::http
diff --git a/server/src/http_common.cppm b/server/src/http_common.cppm
index 606a5d5..f56c92b 100644
--- a/server/src/http_common.cppm
+++ b/server/src/http_common.cppm
@@ -51,119 +51,29 @@ struct supported_verb
 
   supported_verb_t value;
 
-  supported_verb(supported_verb_t value) : value{value} {}
+  supported_verb(supported_verb_t value);
 
-  static auto from(bhttp::verb v) -> std::optional<supported_verb>
-  {
-    switch (v)
-    {
-    case bhttp::verb::options:
-      return supported_verb::options;
-    case bhttp::verb::delete_:
-      return supported_verb::delete_;
-    case bhttp::verb::get:
-      return supported_verb::get;
-    case bhttp::verb::head:
-      return supported_verb::head;
-    case bhttp::verb::post:
-      return supported_verb::post;
-    case bhttp::verb::put:
-      return supported_verb::put;
-    default:
-      return std::nullopt;
-    }
-  }
+  static auto from(bhttp::verb v) -> std::optional<supported_verb>;
 
-  operator bhttp::verb() const
-  {
-    switch (value)
-    {
-    case supported_verb::options:
-      return bhttp::verb::options;
-    case supported_verb::delete_:
-      return bhttp::verb::delete_;
-    case supported_verb::get:
-      return bhttp::verb::get;
-    case supported_verb::head:
-      return bhttp::verb::head;
-    case supported_verb::post:
-      return bhttp::verb::post;
-    case supported_verb::put:
-      return bhttp::verb::put;
-    }
-  }
+  operator bhttp::verb() const;
 };
 
 export struct verb_set
 {
+  bool options : 1 = false;
   bool delete_ : 1 = false;
   bool get : 1 = false;
   bool head : 1 = false;
   bool post : 1 = false;
   bool put : 1 = false;
-  bool options : 1 = false;
 
-  auto enable(supported_verb v) -> void
-  {
-    switch (v.value)
-    {
-    case supported_verb::delete_:
-      delete_ = true;
-      break;
-    case supported_verb::get:
-      get = true;
-      break;
-    case supported_verb::head:
-      head = true;
-      break;
-    case supported_verb::post:
-      post = true;
-      break;
-    case supported_verb::put:
-      put = true;
-      break;
-    case supported_verb::options:
-      options = true;
-      break;
-    default:;
-    }
-  }
+  [[nodiscard]] auto with(supported_verb v) const noexcept -> verb_set;
+  [[nodiscard]] auto empty() const noexcept -> bool;
+  [[nodiscard]] auto to_string() const -> std::string;
 
   auto operator==(verb_set const& rhs) const noexcept -> bool = default;
-
-  auto empty() const -> bool { return *this == verb_set{}; }
-
-  verb_set(std::initializer_list<supported_verb> vs)
-  {
-    for (auto const v : vs)
-      enable(v);
-  }
-
-  auto to_string() const -> std::string
-  {
-    std::ostringstream ss;
-    bool wrote = false;
-    auto write = [&](bhttp::verb v)
-    {
-      if (wrote)
-        ss << ", ";
-      ss << v;
-      wrote = true;
-    };
-    if (delete_)
-      write(bhttp::verb::delete_);
-    if (get)
-      write(bhttp::verb::get);
-    if (head)
-      write(bhttp::verb::head);
-    if (post)
-      write(bhttp::verb::post);
-    if (put)
-      write(bhttp::verb::put);
-    if (options)
-      write(bhttp::verb::options);
-    return ss.str();
-  }
 };
+static_assert(sizeof(verb_set) == 1);
+static_assert(alignof(verb_set) == 1);
 
 } // namespace routemon::http
diff --git a/server/src/http_server.cpp b/server/src/http_server.cpp
new file mode 100644
index 0000000..da8e6f0
--- /dev/null
+++ b/server/src/http_server.cpp
@@ -0,0 +1,188 @@
+module;
+
+#include <boost/asio/as_tuple.hpp>
+#include <boost/asio/awaitable.hpp>
+#include <boost/asio/co_spawn.hpp>
+#include <boost/asio/ip/tcp.hpp>
+#include <boost/beast/core.hpp>
+#include <boost/beast/http.hpp>
+#include <boost/config.hpp>
+#include <boost/json/serialize.hpp>
+#include <boost/url.hpp>
+
+module routemon:http.server$impl;
+
+import :http.server;
+
+namespace routemon::http {
+
+auto presponse::header() -> bhttp::response_header<bhttp::fields>&
+{
+  return impl_->header();
+}
+
+auto presponse::header() const -> bhttp::response_header<bhttp::fields> const&
+{
+  return impl_->header();
+}
+
+auto presponse::is_done() const -> bool { return impl_->is_done(); }
+
+auto presponse::prepare(beast::error_code& ec) -> const_buffers_type
+{
+  return impl_->prepare(ec);
+}
+
+auto presponse::consume(std::size_t n) -> void { return impl_->consume(n); }
+
+auto presponse::keep_alive() const noexcept -> bool
+{
+  return impl_->keep_alive();
+}
+
+keep_alive::keep_alive(bool value) : value{value} {}
+
+auto problem_rsp(
+    base_ctx const& ctx, problem::details const& problem, keep_alive ka)
+    -> presponse
+{
+  auto rsp = make_rsp<bhttp::string_body>(problem.status, ka);
+  rsp.set(bhttp::field::content_type, "application/problem+json");
+  rsp.body() = json::serialize(json::value_from(problem, ctx.locale));
+  rsp.prepare_payload();
+  return presponse{std::move(rsp)};
+}
+
+auto make_preflight_rsp(preflight_response res, keep_alive ka)
+    -> bhttp::response<bhttp::empty_body>
+{
+  auto rsp = make_rsp<bhttp::empty_body>(bhttp::status::no_content, ka);
+  auto allow_headers_str = res.allow_headers
+                           | std::views::transform(
+                               [](auto const& field) -> std::string_view
+                               { return bhttp::to_string(field); })
+                           | std::views::join_with(std::string_view{", "})
+                           | std::ranges::to<std::string>();
+  rsp.set(
+      bhttp::field::access_control_allow_methods,
+      res.allow_methods.to_string());
+  rsp.set(bhttp::field::access_control_allow_headers, allow_headers_str);
+  rsp.prepare_payload();
+  return rsp;
+}
+
+auto global_options_handler(base_ctx const& ctx, readable_request r)
+    -> net::awaitable<presponse>
+{
+  // TODO: switch to "small (4KB) discarded" body type, similar to what Go
+  // does? Same goes for default_options_handler? Not sure.
+  if (auto res = co_await read_request<bhttp::empty_body>(ctx, std::move(r));
+      !res)
+    co_return std::move(res.error());
+  auto req = r.p->release();
+  auto rsp = make_rsp<bhttp::empty_body>(
+      bhttp::status::no_content, keep_alive{req.keep_alive()});
+  rsp.prepare_payload();
+  co_return std::move(rsp);
+}
+
+auto router::handle_request(readable_request r) const
+    -> net::awaitable<presponse>
+{
+  return impl_->handle_request(r);
+}
+
+server::server(log::logger const& l, router&& r)
+  : l_{l.sub("http_server")}, r_{std::move(r)}
+{
+}
+
+auto server::do_session(beast::tcp_stream strm) -> net::awaitable<void>
+{
+  auto buf = beast::flat_buffer{};
+
+  while (true)
+  {
+    auto p0 = bhttp::request_parser<bhttp::empty_body>{};
+    p0.body_limit(boost::none);
+    auto [ec, _] =
+        co_await bhttp::async_read_header(strm, buf, p0, net::as_tuple);
+    if (ec == bhttp::error::end_of_stream)
+      break;
+    else if (ec)
+      throw boost::system::system_error{ec};
+
+    auto http_version = p0.get().version();
+    auto&& rsp = co_await r_.handle_request(
+        readable_request{
+          .p = util::not_null{&p0},
+          .strm = util::not_null{&strm},
+          .buf = util::not_null{&buf},
+        });
+    rsp.header().version(http_version);
+    bool keep_alive = rsp.keep_alive();
+    co_await beast::async_write(strm, std::move(rsp));
+    if (!keep_alive)
+    {
+      break;
+    }
+  }
+
+  strm.socket().shutdown(tcp::socket::shutdown_send);
+}
+
+auto server::do_listen(tcp::endpoint endpoint) -> net::awaitable<void>
+{
+  auto executor = co_await net::this_coro::executor;
+  auto acceptor = tcp::acceptor{executor, endpoint};
+
+  l_.with("endpoint", endpoint.address().to_string())
+      .with("port", std::to_string(endpoint.port()))
+      .info("Serving");
+  while (true)
+  {
+    net::co_spawn(
+        executor,
+        do_session(beast::tcp_stream{co_await acceptor.async_accept()}),
+        [this](std::exception_ptr e)
+        {
+          if (e)
+          {
+            try
+            {
+              std::rethrow_exception(e);
+            }
+            catch (std::exception const& e)
+            {
+              l_.error("Error in session: {}", e.what());
+            }
+          }
+        });
+  }
+}
+
+auto server::spawn(net::io_context& ioc) -> void
+{
+  auto const addr = net::ip::make_address("0.0.0.0");
+  auto const endpoint = tcp::endpoint{addr, 8284};
+
+  // TODO: make exception handling as nice as in srv.cpp
+  net::co_spawn(
+      ioc, do_listen(endpoint),
+      [this](std::exception_ptr e)
+      {
+        if (e)
+        {
+          try
+          {
+            std::rethrow_exception(e);
+          }
+          catch (std::exception const& e)
+          {
+            l_.error("Error: {}", e.what());
+          }
+        }
+      });
+}
+
+} // namespace routemon::http
diff --git a/server/src/http_server.cppm b/server/src/http_server.cppm
index f5b4c3e..dc8c183 100644
--- a/server/src/http_server.cppm
+++ b/server/src/http_server.cppm
@@ -137,25 +137,12 @@ public:
   {
   }
 
-  auto header() -> bhttp::response_header<bhttp::fields>&
-  {
-    return impl_->header();
-  }
-  auto header() const -> bhttp::response_header<bhttp::fields> const&
-  {
-    return impl_->header();
-  }
-
-  auto is_done() const -> bool { return impl_->is_done(); }
-
-  auto prepare(beast::error_code& ec) -> const_buffers_type
-  {
-    return impl_->prepare(ec);
-  }
-
-  auto consume(std::size_t n) -> void { return impl_->consume(n); }
-
-  auto keep_alive() const noexcept -> bool { return impl_->keep_alive(); }
+  auto header() -> bhttp::response_header<bhttp::fields>&;
+  auto header() const -> bhttp::response_header<bhttp::fields> const&;
+  auto is_done() const -> bool;
+  auto prepare(beast::error_code& ec) -> const_buffers_type;
+  auto consume(std::size_t n) -> void;
+  auto keep_alive() const noexcept -> bool;
 };
 static_assert(beast::concepts::buffers_generator<presponse>);
 
@@ -207,15 +194,17 @@ struct base_ctx
 };
 
 template <class Ctx>
-using basic_route_handler_fn_t = std::function<
-    auto(Ctx, readable_request, std::vector<std::string> const& matches)
-        ->net::awaitable<presponse>>;
+using basic_route_handler_fn_t =
+    std::function<auto(
+                      Ctx, readable_request,
+                      std::vector<std::string> const& matches)
+                      ->net::awaitable<presponse>>;
 
 struct keep_alive
 {
   bool value;
 
-  explicit keep_alive(bool value) : value{value} {}
+  explicit keep_alive(bool value);
 };
 
 template <bhttp::concepts::body Body>
@@ -229,37 +218,16 @@ auto make_rsp(bhttp::status status, keep_alive ka) -> bhttp::response<Body>
 
 auto problem_rsp(
     base_ctx const& ctx, problem::details const& problem, keep_alive ka)
-    -> presponse
-{
-  auto rsp = make_rsp<bhttp::string_body>(problem.status, ka);
-  rsp.set(bhttp::field::content_type, "application/problem+json");
-  rsp.body() = json::serialize(json::value_from(problem, ctx.locale));
-  rsp.prepare_payload();
-  return presponse{std::move(rsp)};
-}
+    -> presponse;
 
 struct preflight_response
 {
   verb_set allow_methods;
   std::vector<bhttp::field> allow_headers;
 };
+
 auto make_preflight_rsp(preflight_response res, keep_alive ka)
-    -> bhttp::response<bhttp::empty_body>
-{
-  auto rsp = make_rsp<bhttp::empty_body>(bhttp::status::no_content, ka);
-  auto allow_headers_str = res.allow_headers
-                           | std::views::transform(
-                               [](auto const& field) -> std::string_view
-                               { return bhttp::to_string(field); })
-                           | std::views::join_with(std::string_view{", "})
-                           | std::ranges::to<std::string>();
-  rsp.set(
-      bhttp::field::access_control_allow_methods,
-      res.allow_methods.to_string());
-  rsp.set(bhttp::field::access_control_allow_headers, allow_headers_str);
-  rsp.prepare_payload();
-  return rsp;
-}
+    -> bhttp::response<bhttp::empty_body>;
 
 // Using base_ctx instead of a template here since that saves you
 // typing on invocation (and we do not care about the context type
@@ -276,8 +244,8 @@ auto read_request(base_ctx const& ctx, readable_request&& r)
 
 template <>
 auto read_request<bhttp::empty_body>(base_ctx const& ctx, readable_request&& r)
-    -> net::awaitable<
-        std::expected<bhttp::request<bhttp::empty_body>, presponse>>
+    -> net::
+        awaitable<std::expected<bhttp::request<bhttp::empty_body>, presponse>>
 {
   auto [ec, _] =
       co_await bhttp::async_read(*r.strm, *r.buf, *r.p, net::as_tuple);
@@ -340,19 +308,7 @@ auto default_options_handler(
 }
 
 auto global_options_handler(base_ctx const& ctx, readable_request r)
-    -> net::awaitable<presponse>
-{
-  // TODO: switch to "small (4KB) discarded" body type, similar to what Go
-  // does? Same goes for default_options_handler? Not sure.
-  if (auto res = co_await read_request<bhttp::empty_body>(ctx, std::move(r));
-      !res)
-    co_return std::move(res.error());
-  auto req = r.p->release();
-  auto rsp = make_rsp<bhttp::empty_body>(
-      bhttp::status::no_content, keep_alive{req.keep_alive()});
-  rsp.prepare_payload();
-  co_return std::move(rsp);
-}
+    -> net::awaitable<presponse>;
 
 template <class Ctx>
 auto id_middleware(
@@ -427,28 +383,22 @@ struct handler_map
 
   auto verbs() const -> verb_set
   {
-    auto set = verb_set{};
-    if (static_cast<bool>(options))
-      set.enable(supported_verb::options);
-    if (static_cast<bool>(delete_))
-      set.enable(supported_verb::delete_);
-    if (static_cast<bool>(get))
-      set.enable(supported_verb::get);
-    if (static_cast<bool>(head))
-      set.enable(supported_verb::head);
-    if (static_cast<bool>(post))
-      set.enable(supported_verb::post);
-    if (static_cast<bool>(put))
-      set.enable(supported_verb::put);
-    return set;
+    return verb_set{
+      .options = static_cast<bool>(options),
+      .delete_ = static_cast<bool>(delete_),
+      .get = static_cast<bool>(get),
+      .head = static_cast<bool>(head),
+      .post = static_cast<bool>(post),
+      .put = static_cast<bool>(put),
+    };
   }
 
   auto empty() const -> bool { return verbs().empty(); }
 
   template <std::default_initializable U>
   auto map(std::invocable<V const&> auto f) const -> handler_map<U>
-    requires std::assignable_from<
-        U&, std::invoke_result_t<decltype(f), V const&>>
+    requires std::
+        assignable_from<U&, std::invoke_result_t<decltype(f), V const&>>
   {
     return {
       .options = static_cast<bool>(options) ? f(options) : U{},
@@ -508,8 +458,9 @@ template <class T>
 concept match_arg = std::constructible_from<T, std::string const&>;
 
 template <class Ctx, match_arg... MatchArgs>
-using route_handler_fn_t = std::function<
-    auto(Ctx, readable_request, MatchArgs...)->net::awaitable<presponse>>;
+using route_handler_fn_t =
+    std::function<auto(Ctx, readable_request, MatchArgs...)
+                      ->net::awaitable<presponse>>;
 
 template <class Ctx, match_arg... MatchArgs>
 auto degen_route_handler(route_handler_fn_t<Ctx, MatchArgs...> fn)
@@ -588,271 +539,226 @@ struct dtree : handler_map<route_handler_fn_t<Ctx, MatchArgs...>>
   }
 };
 
-template <std::derived_from<base_ctx> PreRouteCtx>
-class server
+class router
 {
-  log::logger l_;
-  locale::selector lsel_;
-  middleware_t<base_ctx, PreRouteCtx> global_middleware_;
-  route_tree<routed_ctx<PreRouteCtx>> routes_;
-
-public:
-  explicit server(
-      log::logger const& l, locale::selector&& lsel,
-      middleware_t<base_ctx, PreRouteCtx> global_middleware,
-      route_tree<routed_ctx<PreRouteCtx>> routes)
-    : l_{l.sub("http_server")}, lsel_{std::move(lsel)},
-      global_middleware_{std::move(global_middleware)},
-      routes_{std::move(routes)}
-  {
-  }
-
-  struct match_result
+  struct impl_base
   {
-    util::not_null<
-        handler_map<basic_route_handler_fn_t<routed_ctx<PreRouteCtx>>> const*>
-        route_handlers;
-    std::vector<std::string> wildcard_matches;
-
-    auto allowed_methods() const -> verb_set { return route_handlers->verbs(); }
+    virtual ~impl_base() = default;
+    virtual auto handle_request(readable_request r) const
+        -> net::awaitable<presponse> = 0;
   };
 
-  auto match(boost::urls::segments_view segments) const
-      -> std::optional<match_result>
+  std::unique_ptr<impl_base> impl_;
+
+  template <std::derived_from<base_ctx> PreRouteCtx>
+  class impl : public impl_base
   {
-    auto const* tree = &routes_;
-    auto wildcard_matches = std::vector<std::string>{};
-    for (auto const& seg : segments)
+    locale::selector lsel_;
+    middleware_t<base_ctx, PreRouteCtx> global_middleware_;
+    route_tree<routed_ctx<PreRouteCtx>> routes_;
+
+  public:
+    explicit impl(
+        locale::selector&& lsel,
+        middleware_t<base_ctx, PreRouteCtx> global_middleware,
+        route_tree<routed_ctx<PreRouteCtx>> routes)
+      : lsel_{std::move(lsel)},
+        global_middleware_{std::move(global_middleware)},
+        routes_{std::move(routes)}
     {
-      tree->sub.visit(
-          util::overloaded{
-            [&](route_tree<routed_ctx<PreRouteCtx>>::named_subtrees const&
-                    subtrees)
-            {
-              auto it = subtrees.find(seg);
-              tree = it == subtrees.end() ? nullptr : &it->second;
-            },
-            [&](route_tree<routed_ctx<PreRouteCtx>>::wildcard_subtree const&
-                    wildcard_subtree)
-            {
-              wildcard_matches.push_back(seg);
-              tree = &*wildcard_subtree;
-            },
-          });
-      if (!tree)
-        return std::nullopt;
     }
-    if (tree->here.empty())
-      return std::nullopt;
-    return match_result{
-      .route_handlers = util::not_null{&tree->here},
-      .wildcard_matches = wildcard_matches,
-    };
-  }
 
-  auto route_request(PreRouteCtx ctx, readable_request r) const
-      -> net::awaitable<presponse>
-  {
-    auto req_base = r.p->get().base();
+    struct match_result
+    {
+      util::not_null<
+          handler_map<basic_route_handler_fn_t<routed_ctx<PreRouteCtx>>> const*
+      >
+          route_handlers;
+      std::vector<std::string> wildcard_matches;
 
-    auto const bad_request_tpl = problem::tpl{
-      .status = bhttp::status::bad_request,
-      .title = translate("Bad request"),
-      .type_uri = "https://routemon.fautchen.eu/problems/bad-request",
+      auto allowed_methods() const -> verb_set
+      {
+        return route_handlers->verbs();
+      }
     };
 
-    if (req_base.target() == "*")
+    auto match(boost::urls::segments_view segments) const
+        -> std::optional<match_result>
     {
-      // request-target is in asterisk-form (RFC 9112, § 3.2.4),
-      // so the request must be a server-wide OPTIONS request.
-
-      if (req_base.method() != bhttp::verb::options)
+      auto const* tree = &routes_;
+      auto wildcard_matches = std::vector<std::string>{};
+      for (auto const& seg : segments)
       {
-        auto tpl = problem::tpl{
-          .status = bhttp::status::method_not_allowed,
-          .title = translate("Method not allowed"),
-          .type_uri = "https://routemon.fautchen.eu/problems/"
-                      "method-not-allowed",
-        };
-        co_return problem_rsp(ctx, tpl.instantiate(), keep_alive{false});
+        tree->sub.visit(
+            util::overloaded{
+              [&](route_tree<routed_ctx<PreRouteCtx>>::named_subtrees const&
+                      subtrees)
+              {
+                auto it = subtrees.find(seg);
+                tree = it == subtrees.end() ? nullptr : &it->second;
+              },
+              [&](route_tree<routed_ctx<PreRouteCtx>>::wildcard_subtree const&
+                      wildcard_subtree)
+              {
+                wildcard_matches.push_back(seg);
+                tree = &*wildcard_subtree;
+              },
+            });
+        if (!tree)
+          return std::nullopt;
       }
-
-      co_return co_await global_options_handler(ctx, r);
+      if (tree->here.empty())
+        return std::nullopt;
+      return match_result{
+        .route_handlers = util::not_null{&tree->here},
+        .wildcard_matches = wildcard_matches,
+      };
     }
-    else if (auto mreq_url0 = boost::urls::parse_origin_form(req_base.target()))
+
+    auto route_request(PreRouteCtx ctx, readable_request r) const
+        -> net::awaitable<presponse>
     {
-      // request-target is in origin-form (RFC 9112, § 3.2.1),
-      // so it must be a normal request (not a CONNECT or
-      // server-wide OPTIONS request).
+      auto req_base = r.p->get().base();
 
-      auto req_url = boost::urls::url{*mreq_url0};
-      req_url.normalize();
-      if (!req_url.is_path_absolute())
-      {
-        auto problem = bad_request_tpl.instantiate().set_detail(translate(
-            "Path of normalized (RFC 3986, § 6) "
-            "origin-form request-target (RFC "
-            "9112, § 3.2.1) should be "
-            "absolute"));
-        co_return problem_rsp(ctx, problem, keep_alive{false});
-      }
+      auto const bad_request_tpl = problem::tpl{
+        .status = bhttp::status::bad_request,
+        .title = translate("Bad request"),
+        .type_uri = "https://routemon.fautchen.eu/problems/bad-request",
+      };
 
-      auto mres = match(req_url.segments());
-      if (!mres)
+      if (req_base.target() == "*")
       {
-        auto tpl = problem::tpl{
-          .status = bhttp::status::not_found,
-          .title = translate("Not found"),
-          .type_uri = "https://routemon.fautchen.eu/problems/not-found",
-        };
-        co_return problem_rsp(ctx, tpl.instantiate(), keep_alive{false});
-      }
+        // request-target is in asterisk-form (RFC 9112, § 3.2.4),
+        // so the request must be a server-wide OPTIONS request.
 
-      auto mverb = supported_verb::from(req_base.method());
-      if (!mverb)
-      {
-        // Method not implemented.
-        auto tpl = problem::tpl{
-          .status = bhttp::status::not_implemented,
-          .title = translate("Method not implemented"),
-          .type_uri = "https://routemon.fautchen.eu/problems/"
-                      "method-not-implemented",
-        };
-        co_return problem_rsp(ctx, tpl.instantiate(), keep_alive{false});
-      }
+        if (req_base.method() != bhttp::verb::options)
+        {
+          auto tpl = problem::tpl{
+            .status = bhttp::status::method_not_allowed,
+            .title = translate("Method not allowed"),
+            .type_uri = "https://routemon.fautchen.eu/problems/"
+                        "method-not-allowed",
+          };
+          co_return problem_rsp(ctx, tpl.instantiate(), keep_alive{false});
+        }
 
-      if (auto mhdl = mres->route_handlers->lookup(*mverb))
+        co_return co_await global_options_handler(ctx, r);
+      }
+      else if (auto mreq_url0 =
+                   boost::urls::parse_origin_form(req_base.target()))
       {
-        auto new_ctx =
-            routed_ctx<PreRouteCtx>{std::move(ctx), mres->allowed_methods()};
-        co_return co_await mhdl(std::move(new_ctx), r, mres->wildcard_matches);
+        // request-target is in origin-form (RFC 9112, § 3.2.1),
+        // so it must be a normal request (not a CONNECT or
+        // server-wide OPTIONS request).
+
+        auto req_url = boost::urls::url{*mreq_url0};
+        req_url.normalize();
+        if (!req_url.is_path_absolute())
+        {
+          auto problem = bad_request_tpl.instantiate().set_detail(translate(
+              "Path of normalized (RFC 3986, § 6) "
+              "origin-form request-target (RFC "
+              "9112, § 3.2.1) should be "
+              "absolute"));
+          co_return problem_rsp(ctx, problem, keep_alive{false});
+        }
+
+        auto mres = match(req_url.segments());
+        if (!mres)
+        {
+          auto tpl = problem::tpl{
+            .status = bhttp::status::not_found,
+            .title = translate("Not found"),
+            .type_uri = "https://routemon.fautchen.eu/problems/not-found",
+          };
+          co_return problem_rsp(ctx, tpl.instantiate(), keep_alive{false});
+        }
+
+        auto mverb = supported_verb::from(req_base.method());
+        if (!mverb)
+        {
+          // Method not implemented.
+          auto tpl = problem::tpl{
+            .status = bhttp::status::not_implemented,
+            .title = translate("Method not implemented"),
+            .type_uri = "https://routemon.fautchen.eu/problems/"
+                        "method-not-implemented",
+          };
+          co_return problem_rsp(ctx, tpl.instantiate(), keep_alive{false});
+        }
+
+        if (auto mhdl = mres->route_handlers->lookup(*mverb))
+        {
+          auto new_ctx =
+              routed_ctx<PreRouteCtx>{std::move(ctx), mres->allowed_methods()};
+          co_return co_await mhdl(
+              std::move(new_ctx), r, mres->wildcard_matches);
+        }
+        else
+        {
+          // Path recognized, but method not allowed.
+          auto tpl = problem::tpl{
+            .status = bhttp::status::method_not_allowed,
+            .title = translate("Method not allowed"),
+            .type_uri = "https://routemon.fautchen.eu/problems/"
+                        "method-not-allowed",
+          };
+          auto rsp = problem_rsp(ctx, tpl.instantiate(), keep_alive{false});
+          rsp.header().set(
+              bhttp::field::allow, mres->allowed_methods().to_string());
+          co_return std::move(rsp);
+        }
       }
       else
       {
-        // Path recognized, but method not allowed.
-        auto tpl = problem::tpl{
-          .status = bhttp::status::method_not_allowed,
-          .title = translate("Method not allowed"),
-          .type_uri = "https://routemon.fautchen.eu/problems/"
-                      "method-not-allowed",
-        };
-        auto rsp = problem_rsp(ctx, tpl.instantiate(), keep_alive{false});
-        rsp.header().set(
-            bhttp::field::allow, mres->allowed_methods().to_string());
-        co_return std::move(rsp);
+        // We do not accept any other request-target forms.
+
+        auto problem = bad_request_tpl.instantiate().set_detail(translate(
+            "Invalid request-target, expected "
+            "asterisk-form or origin-form "
+            "(see RFC 9112, § 3.2)"));
+        co_return problem_rsp(ctx, problem, keep_alive{false});
       }
     }
-    else
-    {
-      // We do not accept any other request-target forms.
 
-      auto problem = bad_request_tpl.instantiate().set_detail(translate(
-          "Invalid request-target, expected "
-          "asterisk-form or origin-form "
-          "(see RFC 9112, § 3.2)"));
-      co_return problem_rsp(ctx, problem, keep_alive{false});
+    auto handle_request(readable_request r) const
+        -> net::awaitable<presponse> override
+    {
+      auto header = r.p->get().base();
+      auto locale = lsel_.select(header[bhttp::field::accept_language]);
+      co_return co_await global_middleware_(
+          base_ctx{.locale = locale}, header,
+          [&](PreRouteCtx ctx) -> net::awaitable<presponse>
+          { co_return co_await route_request(std::move(ctx), std::move(r)); });
     }
-  }
+  };
 
-  auto handle_request(readable_request r) const -> net::awaitable<presponse>
+public:
+  template <std::derived_from<base_ctx> PreRouteCtx>
+  explicit router(
+      locale::selector&& lsel,
+      middleware_t<base_ctx, PreRouteCtx> global_middleware,
+      route_tree<routed_ctx<PreRouteCtx>> routes)
+    : impl_{std::make_unique<impl<PreRouteCtx>>(
+          std::move(lsel), std::move(global_middleware), std::move(routes))}
   {
-    auto header = r.p->get().base();
-    auto locale = lsel_.select(header[bhttp::field::accept_language]);
-    auto ctx0 = base_ctx{.locale = locale};
-
-    co_return co_await global_middleware_(
-        std::move(ctx0), header,
-        [&](PreRouteCtx ctx) -> net::awaitable<presponse>
-        { co_return co_await route_request(std::move(ctx), std::move(r)); });
   }
 
-  auto do_session(beast::tcp_stream strm) -> net::awaitable<void>
-  {
-    auto buf = beast::flat_buffer{};
-
-    while (true)
-    {
-      auto p0 = bhttp::request_parser<bhttp::empty_body>{};
-      p0.body_limit(boost::none);
-      auto [ec, _] =
-          co_await bhttp::async_read_header(strm, buf, p0, net::as_tuple);
-      if (ec == bhttp::error::end_of_stream)
-        break;
-      else if (ec)
-        throw boost::system::system_error{ec};
-
-      auto http_version = p0.get().version();
-      auto&& rsp = co_await handle_request(
-          readable_request{
-            .p = util::not_null{&p0},
-            .strm = util::not_null{&strm},
-            .buf = util::not_null{&buf},
-          });
-      rsp.header().version(http_version);
-      bool keep_alive = rsp.keep_alive();
-      co_await beast::async_write(strm, std::move(rsp));
-      if (!keep_alive)
-      {
-        break;
-      }
-    }
-
-    strm.socket().shutdown(tcp::socket::shutdown_send);
-  }
+  auto handle_request(readable_request r) const -> net::awaitable<presponse>;
+};
 
-  auto do_listen(tcp::endpoint endpoint) -> net::awaitable<void>
-  {
-    auto executor = co_await net::this_coro::executor;
-    auto acceptor = tcp::acceptor{executor, endpoint};
+class server
+{
+  log::logger l_;
+  router r_;
 
-    l_.with("endpoint", endpoint.address().to_string())
-        .with("port", std::to_string(endpoint.port()))
-        .info("Serving");
-    while (true)
-    {
-      net::co_spawn(
-          executor,
-          do_session(beast::tcp_stream{co_await acceptor.async_accept()}),
-          [this](std::exception_ptr e)
-          {
-            if (e)
-            {
-              try
-              {
-                std::rethrow_exception(e);
-              }
-              catch (std::exception const& e)
-              {
-                l_.error("Error in session: {}", e.what());
-              }
-            }
-          });
-    }
-  }
+  auto do_session(beast::tcp_stream strm) -> net::awaitable<void>;
+  auto do_listen(tcp::endpoint endpoint) -> net::awaitable<void>;
 
-  auto spawn(net::io_context& ioc) -> void
-  {
-    auto const addr = net::ip::make_address("0.0.0.0");
-    auto const endpoint = tcp::endpoint{addr, 8284};
+public:
+  explicit server(log::logger const& l, router&& r);
 
-    // TODO: make exception handling as nice as in srv.cpp
-    net::co_spawn(
-        ioc, do_listen(endpoint),
-        [this](std::exception_ptr e)
-        {
-          if (e)
-          {
-            try
-            {
-              std::rethrow_exception(e);
-            }
-            catch (std::exception const& e)
-            {
-              l_.error("Error: {}", e.what());
-            }
-          }
-        });
-  }
+  auto spawn(net::io_context& ioc) -> void;
 };
 
 } // namespace routemon::http
diff --git a/server/src/locale.cpp b/server/src/locale.cpp
new file mode 100644
index 0000000..652349c
--- /dev/null
+++ b/server/src/locale.cpp
@@ -0,0 +1,232 @@
+module;
+
+#include <boost/locale.hpp>
+#include <unicode/localematcher.h>
+
+module routemon:locale$impl;
+
+import :locale;
+
+namespace routemon::locale {
+
+struct locale_priority
+{
+  float weight;
+  std::size_t original_index;
+};
+
+auto operator<(locale_priority const& lhs, locale_priority const& rhs) -> bool
+{
+  if (lhs.weight != rhs.weight)
+    return lhs.weight > rhs.weight;
+  return lhs.original_index < rhs.original_index;
+}
+
+struct icu_locale_hash
+{
+  std::size_t operator()(icu::Locale const& l) const noexcept
+  {
+    static_assert(sizeof(std::int32_t) < sizeof(std::size_t));
+    std::int32_t hash = l.hashCode();
+    if (hash < 0)
+    {
+      return static_cast<std::size_t>(std::numeric_limits<int>::max())
+             + static_cast<std::size_t>(-hash) + 1;
+    }
+    else
+    {
+      return static_cast<std::size_t>(hash);
+    }
+  }
+};
+
+using icu_locale_priority_map =
+    std::unordered_map<icu::Locale, locale_priority, icu_locale_hash>;
+using icu_priority_locale = std::pair<icu::Locale, locale_priority>;
+
+auto operator<(icu_priority_locale const& lhs, icu_priority_locale const& rhs)
+    -> bool
+{
+  return lhs.second < rhs.second;
+}
+
+class icu_priority_locale_vec_iterator : public icu::Locale::Iterator
+{
+  std::size_t i_ = 0uz;
+  std::vector<icu_priority_locale> ls_;
+
+public:
+  explicit icu_priority_locale_vec_iterator(
+      std::vector<icu_priority_locale>&& ls)
+    : ls_(std::move(ls))
+  {
+  }
+
+  auto hasNext() const -> UBool override { return i_ < ls_.size(); }
+
+  auto next() -> icu::Locale const& override { return ls_[i_++].first; }
+
+  ~icu_priority_locale_vec_iterator() override = default;
+};
+
+// Trimming optional whitespace as defined in RFC 9110, § 12.4.2.
+auto selector::ltrim_ows(std::string_view s) -> std::string_view
+{
+  if (auto i = s.find_first_not_of(" \t"); i != std::string_view::npos)
+    s.remove_prefix(i);
+  return s;
+}
+auto selector::rtrim_ows(std::string_view s) -> std::string_view
+{
+  if (auto i = s.find_last_not_of(" \t"); i != std::string_view::npos)
+    return s.substr(0, i + 1);
+  return s;
+}
+auto selector::trim_ows(std::string_view s) -> std::string_view
+{
+  return rtrim_ows(ltrim_ows(s));
+}
+
+auto selector::from_icu_locale(icu::Locale const& l) const -> std::locale
+{
+  auto posix_name = std::string{l.getLanguage()};
+  if (l.getScript() && std::strlen(l.getScript()) > 0)
+  {
+    posix_name += "_";
+    posix_name += l.getScript();
+  }
+  if (l.getCountry() && std::strlen(l.getCountry()) > 0)
+  {
+    posix_name += "_";
+    posix_name += l.getCountry();
+  }
+  posix_name += ".UTF-8";
+  auto added_at = false;
+  if (l.getVariant() && std::strlen(l.getVariant()) > 0)
+  {
+    added_at = true;
+    posix_name += "@";
+    posix_name += l.getVariant();
+  }
+  auto ec = UErrorCode::U_ZERO_ERROR;
+  auto* keywords = l.createKeywords(ec);
+  if (U_FAILURE(ec))
+    throw std::runtime_error{"failed to create keywords"};
+  if (keywords)
+  {
+    std::int32_t kw_len = 0;
+    char const* kw = nullptr;
+    while (kw = keywords->next(&kw_len, ec), !U_FAILURE(ec) && kw)
+    {
+      auto value =
+          l.getKeywordValue<std::string>(icu::StringPiece(kw, kw_len), ec);
+      if (!added_at)
+      {
+        posix_name += "@";
+        added_at = true;
+      }
+      else
+      {
+        posix_name += ";";
+      }
+      posix_name += kw;
+      posix_name += "=";
+      posix_name += value;
+    }
+    if (U_FAILURE(ec))
+      throw std::runtime_error{"failed to iterate over keywords"};
+    delete keywords;
+  }
+  return lgen_->generate(posix_name);
+}
+
+auto selector::select(std::string_view accept_language) const -> std::locale
+{
+  using namespace std::literals::string_view_literals;
+  // NOTE: can also contain a *;q=0.1
+  // q should have at most 3 digits after period
+  auto dlpm = icu_locale_priority_map{};
+  for (auto const [i, lang_prio] :
+       accept_language | std::views::split(","sv) | std::views::enumerate)
+  {
+    auto [lang_range_ut, mweight_ut] =
+        util::split_on(std::string_view{lang_prio}, ';');
+    auto lang_range_str = trim_ows(lang_range_ut);
+    auto mweight_str = mweight_ut.transform(trim_ows);
+    if (lang_range_str == "*")
+      break;
+
+    auto ec = UErrorCode::U_ZERO_ERROR;
+    auto icu_locale = icu::Locale::forLanguageTag(lang_range_str, ec);
+    if (U_FAILURE(ec) || icu_locale.isBogus())
+      continue; // ignore this locale
+
+    auto weight = 1.0f;
+    if (mweight_str && mweight_str->starts_with("q="))
+    {
+      auto weight_str = mweight_str->substr(2, 4);
+      if (auto mweight =
+              util::parse_float(weight_str, std::chars_format::fixed);
+          mweight && 0.0f < *mweight && *mweight < 1.0f)
+      {
+        weight = *mweight;
+      }
+    }
+
+    if (weight > 0.0f)
+    {
+      dlpm[icu_locale] = {
+        .weight = weight,
+        .original_index = static_cast<std::size_t>(i),
+      };
+    }
+    else
+    {
+      dlpm.erase(icu_locale);
+    }
+  }
+
+  auto desired_locales =
+      std::vector<icu_priority_locale>{dlpm.begin(), dlpm.end()};
+  std::sort(desired_locales.begin(), desired_locales.end());
+  auto it = icu_priority_locale_vec_iterator{std::move(desired_locales)};
+  auto ec = UErrorCode::U_ZERO_ERROR;
+  auto res = matcher_.getBestMatchResult(it, ec);
+  if (U_FAILURE(ec))
+    return default_;
+  auto resolved = res.makeResolvedLocale(ec); // TODO: maybe don't?
+  if (U_FAILURE(ec))
+    return from_icu_locale(*res.getSupportedLocale());
+  return from_icu_locale(resolved);
+}
+
+auto to_bcp47_lang_tag(std::locale locale) -> std::optional<std::string>
+{
+  auto const& locale_info = std::use_facet<blocale::info>(locale);
+  auto ec = UErrorCode::U_ZERO_ERROR;
+  auto bcp47_lang_tag =
+      icu::Locale{locale_info.name().c_str()}.toLanguageTag<std::string>(ec);
+  if (U_FAILURE(ec))
+    return std::nullopt;
+  return bcp47_lang_tag;
+}
+
+#ifdef LOCALEDIR
+#define LOCALEDIR_AUX_XSTR(s) LOCALEDIR_AUX_STR(s)
+#define LOCALEDIR_AUX_STR(s) #s
+constexpr auto messages_path = std::string_view{LOCALEDIR_AUX_XSTR(LOCALEDIR)};
+#undef LOCALEDIR_AUX_STR
+#undef LOCALEDIR_AUX_XSTR
+#else  // ifdef LOCALEDIR
+constexpr auto messages_path = std::string_view{"locale/dev"};
+#endif // ifdef LOCALEDIR
+
+export auto make_generator() -> std::shared_ptr<blocale::generator const>
+{
+  auto lgen = std::make_shared<blocale::generator>();
+  lgen->add_messages_path(std::string{messages_path});
+  lgen->add_messages_domain("routemon");
+  return std::static_pointer_cast<blocale::generator const>(lgen);
+}
+
+} // namespace routemon::locale
diff --git a/server/src/locale.cppm b/server/src/locale.cppm
index da80f76..263de1d 100644
--- a/server/src/locale.cppm
+++ b/server/src/locale.cppm
@@ -11,78 +11,20 @@ import :util;
 export namespace blocale = boost::locale;
 
 export namespace routemon {
+
 using lformat = blocale::format;
 using blocale::gettext;
 using blocale::translate;
+
 } // namespace routemon
 
 namespace routemon::locale {
 
-struct locale_priority
-{
-  float weight;
-  std::size_t original_index;
-};
-
-auto operator<(locale_priority const& lhs, locale_priority const& rhs) -> bool
-{
-  if (lhs.weight != rhs.weight)
-    return lhs.weight > rhs.weight;
-  return lhs.original_index < rhs.original_index;
-}
-
-struct icu_locale_hash
-{
-  std::size_t operator()(icu::Locale const& l) const noexcept
-  {
-    static_assert(sizeof(std::int32_t) < sizeof(std::size_t));
-    std::int32_t hash = l.hashCode();
-    if (hash < 0)
-    {
-      return static_cast<std::size_t>(std::numeric_limits<int>::max())
-             + static_cast<std::size_t>(-hash) + 1;
-    }
-    else
-    {
-      return static_cast<std::size_t>(hash);
-    }
-  }
-};
-
-using icu_locale_priority_map =
-    std::unordered_map<icu::Locale, locale_priority, icu_locale_hash>;
-using icu_priority_locale = std::pair<icu::Locale, locale_priority>;
-
-auto operator<(icu_priority_locale const& lhs, icu_priority_locale const& rhs)
-    -> bool
-{
-  return lhs.second < rhs.second;
-}
-
-class icu_priority_locale_vec_iterator : public icu::Locale::Iterator
-{
-  std::size_t i_ = 0uz;
-  std::vector<icu_priority_locale> ls_;
-
-public:
-  explicit icu_priority_locale_vec_iterator(
-      std::vector<icu_priority_locale>&& ls)
-    : ls_(std::move(ls))
-  {
-  }
-
-  auto hasNext() const -> UBool override { return i_ < ls_.size(); }
-
-  auto next() -> icu::Locale const& override { return ls_[i_++].first; }
-
-  ~icu_priority_locale_vec_iterator() override = default;
-};
-
 export template <class T>
 concept locale_input_range =
     std::ranges::input_range<T>
-    && std::same_as<
-        std::locale const&, std::ranges::range_const_reference_t<T>>;
+    && std::
+        same_as<std::locale const&, std::ranges::range_const_reference_t<T>>;
 
 // Helps select a locale based on the Accept-Language header in an
 // HTTP request.
@@ -122,75 +64,11 @@ export class selector
   }
 
   // Trimming optional whitespace as defined in RFC 9110, § 12.4.2.
-  static auto ltrim_ows(std::string_view s) -> std::string_view
-  {
-    if (auto i = s.find_first_not_of(" \t"); i != std::string_view::npos)
-      s.remove_prefix(i);
-    return s;
-  }
-  static auto rtrim_ows(std::string_view s) -> std::string_view
-  {
-    if (auto i = s.find_last_not_of(" \t"); i != std::string_view::npos)
-      return s.substr(0, i + 1);
-    return s;
-  }
-  static auto trim_ows(std::string_view s) -> std::string_view
-  {
-    return rtrim_ows(ltrim_ows(s));
-  }
+  static auto ltrim_ows(std::string_view s) -> std::string_view;
+  static auto rtrim_ows(std::string_view s) -> std::string_view;
+  static auto trim_ows(std::string_view s) -> std::string_view;
 
-  auto from_icu_locale(icu::Locale const& l) const -> std::locale
-  {
-    auto posix_name = std::string{l.getLanguage()};
-    if (l.getScript() && std::strlen(l.getScript()) > 0)
-    {
-      posix_name += "_";
-      posix_name += l.getScript();
-    }
-    if (l.getCountry() && std::strlen(l.getCountry()) > 0)
-    {
-      posix_name += "_";
-      posix_name += l.getCountry();
-    }
-    posix_name += ".UTF-8";
-    auto added_at = false;
-    if (l.getVariant() && std::strlen(l.getVariant()) > 0)
-    {
-      added_at = true;
-      posix_name += "@";
-      posix_name += l.getVariant();
-    }
-    auto ec = UErrorCode::U_ZERO_ERROR;
-    auto* keywords = l.createKeywords(ec);
-    if (U_FAILURE(ec))
-      throw std::runtime_error{"failed to create keywords"};
-    if (keywords)
-    {
-      std::int32_t kw_len = 0;
-      char const* kw = nullptr;
-      while (kw = keywords->next(&kw_len, ec), !U_FAILURE(ec) && kw)
-      {
-        auto value =
-            l.getKeywordValue<std::string>(icu::StringPiece(kw, kw_len), ec);
-        if (!added_at)
-        {
-          posix_name += "@";
-          added_at = true;
-        }
-        else
-        {
-          posix_name += ";";
-        }
-        posix_name += kw;
-        posix_name += "=";
-        posix_name += value;
-      }
-      if (U_FAILURE(ec))
-        throw std::runtime_error{"failed to iterate over keywords"};
-      delete keywords;
-    }
-    return lgen_->generate(posix_name);
-  }
+  auto from_icu_locale(icu::Locale const& l) const -> std::locale;
 
 public:
   // Note: lgen must live at least as long as the selector constructed here!
@@ -202,94 +80,11 @@ public:
   {
   }
 
-  auto select(std::string_view accept_language) const -> std::locale
-  {
-    using namespace std::literals::string_view_literals;
-    // NOTE: can also contain a *;q=0.1
-    // q should have at most 3 digits after period
-    auto dlpm = icu_locale_priority_map{};
-    for (auto const [i, lang_prio] :
-         accept_language | std::views::split(","sv) | std::views::enumerate)
-    {
-      auto [lang_range_ut, mweight_ut] =
-          util::split_on(std::string_view{lang_prio}, ';');
-      auto lang_range_str = trim_ows(lang_range_ut);
-      auto mweight_str = mweight_ut.transform(trim_ows);
-      if (lang_range_str == "*")
-        break;
-
-      auto ec = UErrorCode::U_ZERO_ERROR;
-      auto icu_locale = icu::Locale::forLanguageTag(lang_range_str, ec);
-      if (U_FAILURE(ec) || icu_locale.isBogus())
-        continue; // ignore this locale
-
-      auto weight = 1.0f;
-      if (mweight_str && mweight_str->starts_with("q="))
-      {
-        auto weight_str = mweight_str->substr(2, 4);
-        if (auto mweight =
-                util::parse_float(weight_str, std::chars_format::fixed);
-            mweight && 0.0f < *mweight && *mweight < 1.0f)
-        {
-          weight = *mweight;
-        }
-      }
-
-      if (weight > 0.0f)
-      {
-        dlpm[icu_locale] = {
-          .weight = weight,
-          .original_index = static_cast<std::size_t>(i),
-        };
-      }
-      else
-      {
-        dlpm.erase(icu_locale);
-      }
-    }
-
-    auto desired_locales =
-        std::vector<icu_priority_locale>{dlpm.begin(), dlpm.end()};
-    std::sort(desired_locales.begin(), desired_locales.end());
-    auto it = icu_priority_locale_vec_iterator{std::move(desired_locales)};
-    auto ec = UErrorCode::U_ZERO_ERROR;
-    auto res = matcher_.getBestMatchResult(it, ec);
-    if (U_FAILURE(ec))
-      return default_;
-    auto resolved = res.makeResolvedLocale(ec); // TODO: maybe don't?
-    if (U_FAILURE(ec))
-      return from_icu_locale(*res.getSupportedLocale());
-    return from_icu_locale(resolved);
-  }
+  auto select(std::string_view accept_language) const -> std::locale;
 };
 
-export auto to_bcp47_lang_tag(std::locale locale) -> std::optional<std::string>
-{
-  auto const& locale_info = std::use_facet<blocale::info>(locale);
-  auto ec = UErrorCode::U_ZERO_ERROR;
-  auto bcp47_lang_tag =
-      icu::Locale{locale_info.name().c_str()}.toLanguageTag<std::string>(ec);
-  if (U_FAILURE(ec))
-    return std::nullopt;
-  return bcp47_lang_tag;
-}
-
-#ifdef LOCALEDIR
-#define LOCALEDIR_AUX_XSTR(s) LOCALEDIR_AUX_STR(s)
-#define LOCALEDIR_AUX_STR(s) #s
-constexpr auto messages_path = std::string_view{LOCALEDIR_AUX_XSTR(LOCALEDIR)};
-#undef LOCALEDIR_AUX_STR
-#undef LOCALEDIR_AUX_XSTR
-#else  // ifdef LOCALEDIR
-constexpr auto messages_path = std::string_view{"locale/dev"};
-#endif // ifdef LOCALEDIR
+auto to_bcp47_lang_tag(std::locale locale) -> std::optional<std::string>;
 
-export auto make_generator() -> std::shared_ptr<blocale::generator const>
-{
-  auto lgen = std::make_shared<blocale::generator>();
-  lgen->add_messages_path(std::string{messages_path});
-  lgen->add_messages_domain("routemon");
-  return std::static_pointer_cast<blocale::generator const>(lgen);
-}
+export auto make_generator() -> std::shared_ptr<blocale::generator const>;
 
 } // namespace routemon::locale
diff --git a/server/src/log.cpp b/server/src/log.cpp
new file mode 100644
index 0000000..7fe725f
--- /dev/null
+++ b/server/src/log.cpp
@@ -0,0 +1,99 @@
+module routemon:log$impl;
+
+import :log;
+
+namespace routemon::log {
+
+auto operator<<(std::ostream& os, level lvl) -> std::ostream&
+{
+  switch (lvl)
+  {
+  case level::debug:
+    os << "dbg";
+    break;
+  case level::info:
+    os << "inf";
+    break;
+  case level::warn:
+    os << "wrn";
+    break;
+  case level::error:
+    os << "err";
+    break;
+  }
+  return os;
+}
+
+sink::sink(enum level lvl) : lvl_{lvl} {}
+
+auto sink::level() const -> enum level { return lvl_; }
+
+auto sink::set_level(enum level lvl) -> void { lvl_ = lvl; }
+
+auto sink::write(tmp_message msg) -> void
+{
+  auto sos = std::osyncstream{os_};
+  sos << "[" << msg.lvl;
+  if (!msg.component.empty())
+    sos << " " << msg.component;
+  sos << "] " << msg.txt;
+  for (auto const& [k, v] : msg.attrs)
+    sos << " " << k << "=" << std::quoted(v);
+  sos << '\n';
+}
+
+auto make_sink(level lvl) -> std::shared_ptr<sink>
+{
+  return std::shared_ptr<sink>{new sink{lvl}};
+}
+
+auto logger::log_at(log::level lvl, std::string_view fmt, std::format_args args)
+    -> logger&
+{
+  if (sink_->level() <= lvl)
+    sink_->write(
+        sink::tmp_message{
+          .lvl = lvl,
+          .component = component_,
+          .txt = std::vformat(fmt, args),
+          .attrs = attrs_,
+        });
+  return *this;
+}
+
+logger::logger(std::shared_ptr<sink> const& sink) : sink_{sink}
+{
+  if (!sink)
+  {
+    throw std::invalid_argument{"logger sink may not be null"};
+  }
+}
+
+auto logger::sub(std::string_view component) const -> logger
+{
+  auto l = *this;
+  if (l.component_.empty())
+  {
+    l.component_ = component;
+  }
+  else
+  {
+    l.component_ += ".";
+    l.component_ += component;
+  }
+  return l;
+}
+
+auto logger::with(std::string const& k, std::string&& v) const -> logger
+{
+  auto l = *this;
+  l.attrs_[k] = std::move(v);
+  return l;
+}
+
+auto logger::with(std::string const& k, std::string_view v) const -> logger
+{
+  return with(k, std::string{v});
+}
+
+} // namespace routemon::log
diff --git a/server/src/log.cppm b/server/src/log.cppm
index 97552b6..dc8c2e1 100644
--- a/server/src/log.cppm
+++ b/server/src/log.cppm
@@ -1,11 +1,3 @@
-module;
-
-// Seems like ADL for std::quoted is broken with
-//   import std;
-// Might be because the _Quoted_string object is defined in
-// std::__detail, which is not exported by the module.
-#include <iomanip>
-
 export module routemon:log;
 
 import std;
@@ -19,35 +11,16 @@ export enum class level : std::uint8_t {
   error,
 };
 
-namespace {
-
-auto operator<<(std::ostream& os, level lvl) -> std::ostream&
-{
-  switch (lvl)
-  {
-  case level::debug:
-    os << "dbg";
-    break;
-  case level::info:
-    os << "inf";
-    break;
-  case level::warn:
-    os << "wrn";
-    break;
-  case level::error:
-    os << "err";
-    break;
-  }
-  return os;
-}
-
-} // namespace
-
 export class sink
 {
   std::atomic<enum level> lvl_;
   std::ostream& os_ = std::cout;
 
+  explicit sink(level lvl);
+
+  friend auto make_sink(level lvl) -> std::shared_ptr<sink>;
+
+public:
   struct tmp_message
   {
     level lvl;
@@ -56,35 +29,13 @@ export class sink
     std::map<std::string, std::string> const& attrs;
   };
 
-  auto write(tmp_message msg) -> void
-  {
-    auto sos = std::osyncstream{os_};
-    sos << "[" << msg.lvl;
-    if (!msg.component.empty())
-      sos << " " << msg.component;
-    sos << "] " << msg.txt;
-    for (auto const& [k, v] : msg.attrs)
-    {
-      sos << " " << k << "=" << std::quoted(v);
-    }
-    sos << '\n';
-  }
-
-  explicit sink(level lvl) : lvl_{lvl} {}
-
-  friend auto make_sink(level lvl) -> std::shared_ptr<sink>;
-  friend class logger;
-
-public:
-  [[nodiscard]] auto level() const -> enum level { return lvl_; }
+  [[nodiscard]] auto level() const -> enum level;
+  auto set_level(enum level lvl) -> void;
 
-  auto set_level(enum level lvl) -> void { lvl_ = lvl; }
+  auto write(tmp_message msg) -> void;
 };
 
-export auto make_sink(level lvl) -> std::shared_ptr<sink>
-{
-  return std::shared_ptr<sink>{new sink{lvl}};
-}
+export auto make_sink(level lvl) -> std::shared_ptr<sink>;
 
 export class logger
 {
@@ -92,79 +43,40 @@ export class logger
   std::string component_;
   std::map<std::string, std::string> attrs_;
 
-  template <log::level lvl>
-  auto log_at(std::string_view fmt, std::format_args args) -> logger&
-  {
-    if (sink_->level() <= lvl)
-      sink_->write(
-          sink::tmp_message{
-            .lvl = lvl,
-            .component = component_,
-            .txt = std::vformat(fmt, args),
-            .attrs = attrs_,
-          });
-    return *this;
-  }
+  auto log_at(log::level lvl, std::string_view fmt, std::format_args args)
+      -> logger&;
 
 public:
-  explicit logger(std::shared_ptr<sink> const& sink) : sink_{sink}
-  {
-    if (!sink)
-    {
-      throw std::invalid_argument{"logger sink may not be null"};
-    }
-  }
-
-  [[nodiscard]] auto sub(std::string_view component) const -> logger
-  {
-    auto l = *this;
-    if (l.component_.empty())
-    {
-      l.component_ = component;
-    }
-    else
-    {
-      l.component_ += ".";
-      l.component_ += component;
-    }
-    return l;
-  }
-
-  [[nodiscard]] auto with(std::string const& k, std::string&& v) const -> logger
-  {
-    auto l = *this;
-    l.attrs_[k] = std::move(v);
-    return l;
-  }
+  explicit logger(std::shared_ptr<sink> const& sink);
 
+  [[nodiscard]] auto sub(std::string_view component) const -> logger;
+  [[nodiscard]] auto with(std::string const& k, std::string&& v) const
+      -> logger;
   [[nodiscard]] auto with(std::string const& k, std::string_view v) const
-      -> logger
-  {
-    return with(k, std::string{v});
-  }
+      -> logger;
 
   template <class... Args>
   auto debug(std::format_string<Args...> fmt, Args&&... args) -> logger&
   {
-    return log_at<level::debug>(fmt.get(), std::make_format_args(args...));
+    return log_at(level::debug, fmt.get(), std::make_format_args(args...));
   }
 
   template <class... Args>
   auto info(std::format_string<Args...> fmt, Args&&... args) -> logger&
   {
-    return log_at<level::info>(fmt.get(), std::make_format_args(args...));
+    return log_at(level::info, fmt.get(), std::make_format_args(args...));
   }
 
   template <class... Args>
   auto warn(std::format_string<Args...> fmt, Args&&... args) -> logger&
   {
-    return log_at<level::warn>(fmt.get(), std::make_format_args(args...));
+    return log_at(level::warn, fmt.get(), std::make_format_args(args...));
   }
 
   template <class... Args>
   auto error(std::format_string<Args...> fmt, Args&&... args) -> logger&
   {
-    return log_at<level::error>(fmt.get(), std::make_format_args(args...));
+    return log_at(level::error, fmt.get(), std::make_format_args(args...));
   }
 };
 
diff --git a/server/src/problem.cpp b/server/src/problem.cpp
new file mode 100644
index 0000000..3608f38
--- /dev/null
+++ b/server/src/problem.cpp
@@ -0,0 +1,52 @@
+module;
+
+#include <boost/beast/http/message.hpp>
+#include <boost/json.hpp>
+#include <boost/locale/message.hpp>
+
+module routemon:problem$impl;
+
+import :problem;
+
+namespace routemon::problem {
+
+auto details::set_detail(blocale::message detail) -> details&
+{
+  this->detail = detail;
+  return *this;
+}
+
+auto details::set_instance(std::string&& instance) -> details&
+{
+  this->instance = instance;
+  return *this;
+}
+
+auto details::set_instance(std::string_view instance) -> details&
+{
+  this->instance = std::string{instance};
+  return *this;
+}
+
+auto tag_invoke(
+    json::value_from_tag, json::value& jv, details const& details,
+    std::locale locale) -> void
+{
+  auto obj = json::object{
+    {"type", details.type_uri},
+    {"title", details.title.str(locale)},
+    {"status", static_cast<unsigned>(details.status)},
+  };
+  if (details.detail)
+    obj["detail"] = details.detail->str(locale);
+  if (details.instance)
+    obj["instance"] = *details.instance;
+  jv = obj;
+}
+
+auto tpl::instantiate() const -> details
+{
+  return details{status, title, type_uri};
+}
+
+} // namespace routemon::problem
diff --git a/server/src/problem.cppm b/server/src/problem.cppm
index 37e6257..18c2fe2 100644
--- a/server/src/problem.cppm
+++ b/server/src/problem.cppm
@@ -22,39 +22,14 @@ export struct details
   std::optional<blocale::message> detail = std::nullopt;
   std::optional<std::string> instance = std::nullopt;
 
-  auto set_detail(blocale::message detail) -> details&
-  {
-    this->detail = detail;
-    return *this;
-  }
-
-  auto set_instance(std::string&& instance) -> details&
-  {
-    this->instance = instance;
-    return *this;
-  }
-  auto set_instance(std::string_view instance) -> details&
-  {
-    this->instance = std::string{instance};
-    return *this;
-  }
+  auto set_detail(blocale::message detail) -> details&;
+  auto set_instance(std::string&& instance) -> details&;
+  auto set_instance(std::string_view instance) -> details&;
 };
 
-export auto tag_invoke(
+auto tag_invoke(
     json::value_from_tag, json::value& jv, details const& details,
-    std::locale locale) -> void
-{
-  auto obj = json::object{
-    {"type", details.type_uri},
-    {"title", details.title.str(locale)},
-    {"status", static_cast<unsigned>(details.status)},
-  };
-  if (details.detail)
-    obj["detail"] = details.detail->str(locale);
-  if (details.instance)
-    obj["instance"] = *details.instance;
-  jv = obj;
-}
+    std::locale locale) -> void;
 
 export struct tpl
 {
@@ -62,10 +37,7 @@ export struct tpl
   blocale::message title;
   std::string_view type_uri;
 
-  auto instantiate() const -> details
-  {
-    return details{status, title, type_uri};
-  }
+  auto instantiate() const -> details;
 };
 
 } // namespace routemon::problem
diff --git a/server/src/req_ctx.cppm b/server/src/req_ctx.cppm
deleted file mode 100644
index 4a64d7d..0000000
--- a/server/src/req_ctx.cppm
+++ /dev/null
@@ -1,48 +0,0 @@
-module;
-
-#include <boost/beast/http/message.hpp>
-#include <boost/beast/http/verb.hpp>
-
-export module routemon:req_ctx;
-
-import :http.common;
-import :trace;
-
-namespace routemon {
-
-export class req_ctx
-{
-  trace::id tid_;
-  std::locale locale_;
-  http::verb_set route_verbs_;
-  bool keep_alive_;
-  bhttp::request_header<bhttp::fields> const& req_header_;
-
-public:
-  explicit req_ctx(
-      trace::id tid, std::locale locale, http::verb_set route_verbs,
-      bool keep_alive, bhttp::request_header<bhttp::fields> const& req_header)
-    : tid_{tid}, locale_{locale}, route_verbs_{route_verbs},
-      keep_alive_{keep_alive}, req_header_{req_header}
-  {
-  }
-
-  template <typename ReqBody>
-  explicit req_ctx(
-      trace::id tid, std::locale locale, http::verb_set route_verbs,
-      bhttp::request<ReqBody> const& req)
-    : req_ctx{tid, locale, route_verbs, req.keep_alive(), req.base()}
-  {
-  }
-
-  auto trace_id() const -> trace::id { return tid_; }
-  auto locale() const -> std::locale { return locale_; }
-  auto route_verbs() const -> http::verb_set { return route_verbs_; }
-  auto keep_alive() const -> bool { return keep_alive_; }
-  auto req_header() const -> bhttp::request_header<bhttp::fields> const&
-  {
-    return req_header_;
-  }
-};
-
-} // namespace routemon
diff --git a/server/src/rwgps.cpp b/server/src/rwgps.cpp
new file mode 100644
index 0000000..b8ebf11
--- /dev/null
+++ b/server/src/rwgps.cpp
@@ -0,0 +1,150 @@
+module;
+
+#include <boost/beast/core.hpp>
+#include <boost/beast/http.hpp>
+#include <boost/json.hpp>
+
+module routemon:rwgps$impl;
+
+import :rwgps;
+
+namespace beast = boost::beast;
+namespace bhttp = beast::http;
+namespace json = boost::json;
+
+namespace routemon::rwgps {
+
+export struct route_summary
+{
+  std::int64_t id;
+  std::int64_t user_id;
+  std::string url;
+  std::string name;
+  std::string description;
+};
+
+struct pagination
+{
+  std::size_t record_count;
+  std::size_t page_count;
+  std::size_t page_size;
+  std::optional<std::string> next_page_url;
+};
+
+struct get_routes_meta
+{
+  pagination pagination;
+};
+
+struct get_routes_response
+{
+  std::vector<route_summary> routes;
+  get_routes_meta meta;
+};
+
+auto tag_invoke(json::value_to_tag<route_summary> const&, json::value const& jv)
+    -> route_summary
+{
+  return {
+    .id = json::value_to<std::int64_t>(jv.at("id")),
+    .user_id = json::value_to<std::int64_t>(jv.at("user_id")),
+    .url = json::value_to<std::string>(jv.at("url")),
+    .name = json::value_to<std::string>(jv.at("name")),
+    .description = json::value_to<std::string>(jv.at("description")),
+  };
+}
+
+auto tag_invoke(json::value_to_tag<pagination> const&, json::value const& jv)
+    -> pagination
+{
+  return {
+    .record_count = json::value_to<std::size_t>(jv.at("record_count")),
+    .page_count = json::value_to<std::size_t>(jv.at("page_count")),
+    .page_size = json::value_to<std::size_t>(jv.at("page_size")),
+    .next_page_url =
+        json::value_to<std::optional<std::string>>(jv.at("next_page_url")),
+  };
+}
+
+auto tag_invoke(
+    json::value_to_tag<get_routes_meta> const&, json::value const& jv)
+    -> get_routes_meta
+{
+  return {
+    .pagination = json::value_to<pagination>(jv.at("pagination")),
+  };
+}
+
+auto tag_invoke(
+    json::value_to_tag<get_routes_response> const&, json::value const& jv)
+    -> get_routes_response
+{
+  return {
+    .routes = json::value_to<std::vector<route_summary>>(jv.at("routes")),
+    .meta = json::value_to<get_routes_meta>(jv.at("meta")),
+  };
+}
+
+auto json_value_to_get_routes_response(json::value const& jv)
+    -> get_routes_response
+{
+  return json::value_to<get_routes_response>(jv);
+}
+
+constexpr std::string host = "ridewithgps.com";
+
+// TODO: handle failure appropriately
+auto client::get_routes_page(std::size_t page) -> get_routes_response
+{
+  auto req = bhttp::request<bhttp::string_body>{
+    bhttp::verb::get,
+    std::format("/api/v1/routes.json?page_size=200?page={}", page),
+    11, // HTTP 1.1
+  };
+  req.set(bhttp::field::host, host);
+  req.set("x-rwgps-api-key", api_key_);
+  req.set("x-rwgps-auth-token", auth_token_);
+
+  auto rsp = hc_.do_request(req);
+  auto p = json::stream_parser{};
+  for (auto const frag : rsp.body().cdata())
+    p.write(static_cast<char const*>(frag.data()), frag.size());
+  assert(p.done());
+  return json_value_to_get_routes_response(p.release());
+}
+
+client::client(
+    net::io_context& ioc, log::logger const& l, std::string api_key,
+    std::string auth_token)
+  : l_{l.sub("rwgps-client")}, hc_{ioc}, api_key_{std::move(api_key)},
+    auth_token_{std::move(auth_token)}
+{
+}
+
+auto client::get_all_routes() -> std::vector<route_summary>
+{
+  // TODO: make sure that there are no duplicates here.
+  // What does RWGPS sort on, by default?
+  // Consider using an associative container instead of a vector.
+  auto record_count = 0uz;
+  auto current_page = 0uz;
+  auto routes = std::vector<route_summary>{};
+
+  while (true)
+  {
+    auto rsp = get_routes_page(current_page);
+    if (rsp.meta.pagination.next_page_url)
+      l_.debug("Next page URL: {}", *rsp.meta.pagination.next_page_url);
+    routes.append_range(rsp.routes);
+    if (rsp.meta.pagination.record_count > 0)
+      record_count = rsp.meta.pagination.record_count;
+    if (rsp.routes.empty() || routes.size() >= record_count)
+    {
+      break;
+    }
+  }
+
+  return routes;
+}
+
+} // namespace routemon::rwgps
diff --git a/server/src/rwgps.cppm b/server/src/rwgps.cppm
index 3b01e6c..2ed124e 100644
--- a/server/src/rwgps.cppm
+++ b/server/src/rwgps.cppm
@@ -1,8 +1,6 @@
 module;
 
-#include <boost/beast/core.hpp>
-#include <boost/beast/http.hpp>
-#include <boost/json.hpp>
+#include <boost/asio/io_context.hpp>
 
 export module routemon:rwgps;
 
@@ -10,10 +8,7 @@ import std;
 import :http.client;
 import :log;
 
-namespace beast = boost::beast;
-namespace bhttp = beast::http;
 namespace net = boost::asio;
-namespace json = boost::json;
 
 namespace routemon::rwgps {
 
@@ -45,55 +40,6 @@ struct get_routes_response
   get_routes_meta meta;
 };
 
-auto tag_invoke(json::value_to_tag<route_summary> const&, json::value const& jv)
-    -> route_summary
-{
-  return {
-    .id = json::value_to<std::int64_t>(jv.at("id")),
-    .user_id = json::value_to<std::int64_t>(jv.at("user_id")),
-    .url = json::value_to<std::string>(jv.at("url")),
-    .name = json::value_to<std::string>(jv.at("name")),
-    .description = json::value_to<std::string>(jv.at("description")),
-  };
-}
-
-auto tag_invoke(json::value_to_tag<pagination> const&, json::value const& jv)
-    -> pagination
-{
-  return {
-    .record_count = json::value_to<std::size_t>(jv.at("record_count")),
-    .page_count = json::value_to<std::size_t>(jv.at("page_count")),
-    .page_size = json::value_to<std::size_t>(jv.at("page_size")),
-    .next_page_url =
-        json::value_to<std::optional<std::string>>(jv.at("next_page_url")),
-  };
-}
-
-auto tag_invoke(
-    json::value_to_tag<get_routes_meta> const&, json::value const& jv)
-    -> get_routes_meta
-{
-  return {
-    .pagination = json::value_to<pagination>(jv.at("pagination")),
-  };
-}
-
-auto tag_invoke(
-    json::value_to_tag<get_routes_response> const&, json::value const& jv)
-    -> get_routes_response
-{
-  return {
-    .routes = json::value_to<std::vector<route_summary>>(jv.at("routes")),
-    .meta = json::value_to<get_routes_meta>(jv.at("meta")),
-  };
-}
-
-auto json_value_to_get_routes_response(json::value const& jv)
-    -> get_routes_response
-{
-  return json::value_to<get_routes_response>(jv);
-}
-
 export class client
 {
   log::logger l_;
@@ -101,64 +47,14 @@ export class client
   std::string api_key_;
   std::string auth_token_;
 
-  static constexpr std::string host = "ridewithgps.com";
-
-  // TODO: handle failure appropriately
-  auto get_routes_page(std::size_t page) -> get_routes_response
-  {
-    auto req = bhttp::request<bhttp::string_body>{
-      bhttp::verb::get,
-      std::format("/api/v1/routes.json?page_size=200?page={}", page),
-      11, // HTTP 1.1
-    };
-    req.set(bhttp::field::host, host);
-    req.set("x-rwgps-api-key", api_key_);
-    req.set("x-rwgps-auth-token", auth_token_);
-
-    auto rsp = hc_.do_request(req);
-    auto p = json::stream_parser{};
-    for (auto const frag : rsp.body().cdata())
-    {
-      p.write(static_cast<char const*>(frag.data()), frag.size());
-    }
-    assert(p.done());
-    return json_value_to_get_routes_response(p.release());
-  }
+  auto get_routes_page(std::size_t page) -> get_routes_response;
 
 public:
   explicit client(
       net::io_context& ioc, log::logger const& l, std::string api_key,
-      std::string auth_token)
-    : l_{l.sub("rwgps-client")}, hc_{ioc}, api_key_{std::move(api_key)},
-      auth_token_{std::move(auth_token)}
-  {
-  }
-
-  auto get_all_routes() -> std::vector<route_summary>
-  {
-    // TODO: make sure that there are no duplicates here.
-    // What does RWGPS sort on, by default?
-    // Consider using an associative container instead of a vector.
-    auto record_count = 0uz;
-    auto current_page = 0uz;
-    auto routes = std::vector<route_summary>{};
-
-    while (true)
-    {
-      auto rsp = get_routes_page(current_page);
-      if (rsp.meta.pagination.next_page_url)
-        l_.debug("Next page URL: {}", *rsp.meta.pagination.next_page_url);
-      routes.append_range(rsp.routes);
-      if (rsp.meta.pagination.record_count > 0)
-        record_count = rsp.meta.pagination.record_count;
-      if (rsp.routes.empty() || routes.size() >= record_count)
-      {
-        break;
-      }
-    }
+      std::string auth_token);
 
-    return routes;
-  }
+  auto get_all_routes() -> std::vector<route_summary>;
 };
 
 } // namespace routemon::rwgps
diff --git a/server/src/sqlite3.cpp b/server/src/sqlite3.cpp
new file mode 100644
index 0000000..3e0d64a
--- /dev/null
+++ b/server/src/sqlite3.cpp
@@ -0,0 +1,218 @@
+module;
+
+#include <sqlite3.h>
+
+module routemon:sqlite3$impl;
+
+import :sqlite3;
+
+namespace routemon::sqlite3 {
+
+mutex_guard::mutex_guard(::sqlite3_mutex* mut) noexcept : mut_{mut} {}
+
+mutex_guard::~mutex_guard() { ::sqlite3_mutex_leave(mut_); }
+
+auto do_guarded(::sqlite3_mutex* mut, std::invocable<mutex_guard const&> auto f)
+    -> decltype(f(std::declval<mutex_guard const&>()))
+{
+  return f(mutex_guard{mut});
+}
+
+auto do_guarded(::sqlite3* dbc, std::invocable<mutex_guard const&> auto f)
+    -> decltype(f(std::declval<mutex_guard const&>()))
+{
+  return do_guarded(::sqlite3_db_mutex(dbc), f);
+}
+
+error::error(mutex_guard const&, int code, ::sqlite3* dbc)
+  : code_{code}, message_{::sqlite3_errmsg(dbc)}
+{
+}
+
+error::error(int code) : code_{code}, message_{::sqlite3_errstr(code)} {}
+
+[[nodiscard]] auto error::what() const noexcept -> char const*
+{
+  return message_.c_str();
+}
+
+[[nodiscard]] auto error::code() const noexcept -> int { return code_; }
+
+statement::statement(::sqlite3_stmt* stmt) : stmt_{stmt} {}
+statement::statement(statement&& s) noexcept
+{
+  stmt_ = s.stmt_;
+  s.stmt_ = nullptr;
+}
+statement::~statement() { ::sqlite3_finalize(stmt_); }
+auto statement::get() -> ::sqlite3_stmt* { return stmt_; }
+
+row_reader::row_reader(statement stmt) : stmt_{std::move(stmt)} {}
+
+auto row_reader::is_null(int col) -> bool
+{
+  return ::sqlite3_column_type(stmt_.get(), col) == SQLITE_NULL;
+}
+
+auto row_reader::ncols() -> std::size_t
+{
+  auto const mncols = util::size_from_int(::sqlite3_data_count(stmt_.get()));
+  if (!mncols.has_value())
+    throw std::logic_error{"got unexpected negative amount of columns"};
+  return *mncols;
+}
+
+auto row_reader::scan(int col, std::string& s) -> void
+{
+  if (::sqlite3_column_type(stmt_.get(), col) != SQLITE_TEXT)
+    throw std::invalid_argument{"invalid type for scan"};
+  unsigned char const* chs = ::sqlite3_column_text(stmt_.get(), col);
+  auto size = util::size_from_int(::sqlite3_column_bytes(stmt_.get(), col));
+  if (!size.has_value())
+    throw std::logic_error{"unexpected negative amount of bytes in column"};
+  s = std::string{reinterpret_cast<char const*>(chs), *size};
+}
+
+auto row_reader::scan(int col, double& v) -> void
+{
+  if (::sqlite3_column_type(stmt_.get(), col) != SQLITE_FLOAT)
+    throw std::invalid_argument{"invalid type for scan"};
+  v = ::sqlite3_column_double(stmt_.get(), col);
+}
+
+auto row_reader::scan(int col, std::int64_t& v) -> void
+{
+  if (::sqlite3_column_type(stmt_.get(), col) != SQLITE_INTEGER)
+    throw std::invalid_argument{"invalid type for scan"};
+  v = ::sqlite3_column_int64(stmt_.get(), col);
+}
+
+auto row_reader::next() -> bool
+{
+  ::sqlite3* dbc = ::sqlite3_db_handle(stmt_.get());
+  return do_guarded(
+      dbc,
+      [&](auto const& guard) -> bool
+      {
+        auto const s = ::sqlite3_step(stmt_.get());
+        if (s == SQLITE_ROW)
+          return true;
+        if (s == SQLITE_DONE)
+          return false;
+        throw error{guard, s, dbc};
+      });
+}
+
+binder::binder(statement& stmt) : stmt_{stmt} {}
+
+auto binder::text(std::string const& param_name, std::string_view str) -> void
+{
+  int const i = ::sqlite3_bind_parameter_index(stmt_.get(), param_name.c_str());
+  if (i == 0)
+    throw std::invalid_argument{std::format(
+        "bind: no parameter with name {} found", param_name)};
+  auto str_size = util::int_from_size(str.size());
+  if (!str_size.has_value())
+    throw std::invalid_argument{"bind: provided text is too long"};
+  if (auto s = ::sqlite3_bind_text(
+          stmt_.get(), i, str.data(), *str_size, SQLITE_TRANSIENT);
+      s != SQLITE_OK)
+  {
+    throw error{s};
+  }
+}
+
+auto binder::noop(binder&) -> void {}
+
+connection::connection(::sqlite3* dbc)
+  : dbc_{dbc}, mut_{::sqlite3_db_mutex(dbc)}
+{
+}
+
+connection::connection(connection const&) = delete;
+connection::connection(connection&& c) noexcept
+{
+  dbc_ = c.dbc_;
+  mut_ = c.mut_;
+  c.dbc_ = nullptr;
+  c.mut_ = nullptr;
+}
+
+auto connection::query(
+    std::string const& sql, std::function<void(binder&)> const& bf)
+    -> row_reader
+{
+  ::sqlite3_stmt* pstmt = nullptr;
+  char const* sql_tail = nullptr;
+  auto sql_size = util::int_from_size(sql.size());
+  if (!sql_size.has_value() || *sql_size >= std::numeric_limits<int>::max() - 1)
+    throw std::invalid_argument{"provided input text too large"};
+  do_guarded(
+      mut_,
+      [&](auto const& guard) -> void
+      {
+        if (auto s = ::sqlite3_prepare_v2(
+                dbc_, sql.data(), *sql_size + 1, &pstmt, &sql_tail);
+            s != SQLITE_OK)
+        {
+          if (pstmt != nullptr)
+          {
+            // Use contract_assert when having a compiler with
+            // contracts available
+            ::sqlite3_finalize(pstmt);
+            throw std::logic_error{
+              "expected stmt to be null after failed preparation"
+            };
+          }
+          throw error{guard, s, dbc_};
+        }
+      });
+  if (!pstmt)
+    throw std::invalid_argument{"provided input text contains no SQL"};
+  auto stmt = statement{pstmt};
+  if (sql_tail && std::strlen(sql_tail) > 0)
+    throw std::invalid_argument{
+      "provided input text contains more than one SQL statement"
+    };
+  auto b = binder{stmt};
+  bf(b);
+  return row_reader{std::move(stmt)};
+}
+
+auto connection::exec(
+    std::string const& sql, std::function<void(binder&)> const& bf) -> void
+{
+  auto reader = query(sql, bf);
+  while (reader.next())
+    ;
+}
+
+connection::~connection()
+{
+  std::ignore = ::sqlite3_close(std::exchange(dbc_, nullptr));
+}
+
+auto open(std::string const& filename) -> connection
+{
+  ::sqlite3* dbc = nullptr;
+  auto s = ::sqlite3_open_v2(
+      filename.c_str(), &dbc,
+      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | SQLITE_OPEN_FULLMUTEX
+          | SQLITE_OPEN_EXRESCODE,
+      nullptr);
+  if (s != SQLITE_OK)
+  {
+    if (dbc)
+    {
+      do_guarded(
+          dbc, [&](auto const& guard) -> void { throw error{guard, s, dbc}; });
+    }
+    else
+    {
+      throw error{s};
+    }
+  }
+  return connection{dbc};
+}
+
+} // namespace routemon::sqlite3
diff --git a/server/src/sqlite3.cppm b/server/src/sqlite3.cppm
index 4623cdc..b771c49 100644
--- a/server/src/sqlite3.cppm
+++ b/server/src/sqlite3.cppm
@@ -1,20 +1,34 @@
-module;
-
-#include <sqlite3.h>
-
 export module routemon:sqlite3;
 
 import std;
 import :util;
 
+extern "C"
+{
+  using sqlite3 = struct sqlite3;
+  using sqlite3_mutex = struct sqlite3_mutex;
+  using sqlite3_stmt = struct sqlite3_stmt;
+}
+
 namespace routemon::sqlite3 {
 
+template <class T, template <class U> concept C>
+concept optional_of = requires {
+  typename T::value_type;
+  requires std::same_as<T, std::optional<typename T::value_type>>;
+  requires C<typename T::value_type>;
+};
+
+template <class T>
+concept scannable_prim = std::same_as<T, std::string> || std::same_as<T, double>
+                         || std::same_as<T, std::int64_t>;
+
+template <class T>
+concept scannable = scannable_prim<T> || optional_of<T, scannable_prim>;
+
 class mutex_guard
 {
-  explicit mutex_guard(::sqlite3_mutex* mut) noexcept : mut_{mut}
-  {
-    ::sqlite3_mutex_enter(mut_);
-  }
+  explicit mutex_guard(::sqlite3_mutex* mut) noexcept;
 
   friend auto
   do_guarded(::sqlite3_mutex* mut, std::invocable<mutex_guard const&> auto f)
@@ -22,111 +36,54 @@ class mutex_guard
 
 public:
   mutex_guard(mutex_guard const&) = delete;
-  ~mutex_guard() { ::sqlite3_mutex_leave(mut_); }
+  ~mutex_guard();
 
 private:
   ::sqlite3_mutex* mut_;
 };
 
-auto do_guarded(::sqlite3_mutex* mut, std::invocable<mutex_guard const&> auto f)
-    -> decltype(f(std::declval<mutex_guard const&>()))
-{
-  return f(mutex_guard{mut});
-}
-
-auto do_guarded(::sqlite3* dbc, std::invocable<mutex_guard const&> auto f)
-    -> decltype(f(std::declval<mutex_guard const&>()))
-{
-  return do_guarded(::sqlite3_db_mutex(dbc), f);
-}
-
 class error : public std::exception
 {
   int code_;
   std::string message_;
 
 public:
-  explicit error(mutex_guard const&, int code, ::sqlite3* dbc)
-    : code_{code}, message_{::sqlite3_errmsg(dbc)}
-  {
-  }
-
-  explicit error(int code) : code_{code}, message_{::sqlite3_errstr(code)} {}
-
-  [[nodiscard]] auto what() const noexcept -> char const* override
-  {
-    return message_.c_str();
-  }
+  explicit error(mutex_guard const&, int code, ::sqlite3* dbc);
+  explicit error(int code);
 
-  [[nodiscard]] auto code() const noexcept -> int { return code_; }
-};
-
-template <class T, template <class U> concept C>
-concept optional_of = requires {
-  typename T::value_type;
-  requires std::same_as<T, std::optional<typename T::value_type>>;
-  requires C<typename T::value_type>;
+  [[nodiscard]] auto what() const noexcept -> char const* override;
+  [[nodiscard]] auto code() const noexcept -> int;
 };
 
-template <class T>
-concept scannable_prim = std::same_as<T, std::string> || std::same_as<T, double>
-                         || std::same_as<T, std::int64_t>;
-
-template <class T>
-concept scannable = scannable_prim<T> || optional_of<T, scannable_prim>;
-
 class statement
 {
   ::sqlite3_stmt* stmt_;
 
 public:
-  explicit statement(::sqlite3_stmt* stmt) : stmt_{stmt} {}
+  explicit statement(::sqlite3_stmt* stmt);
   statement(statement const&) = delete;
-  statement(statement&& s) noexcept
-  {
-    stmt_ = s.stmt_;
-    s.stmt_ = nullptr;
-  }
-  ~statement() { ::sqlite3_finalize(stmt_); }
-  auto get() -> ::sqlite3_stmt* { return stmt_; }
+  statement(statement&& s) noexcept;
+  ~statement();
+  auto get() -> ::sqlite3_stmt*;
 };
 
 class row_reader
 {
   statement stmt_;
 
-  explicit row_reader(statement stmt) : stmt_{std::move(stmt)} {}
+  explicit row_reader(statement stmt);
 
   friend class connection;
 
-  void scan(int col, std::string& s)
-  {
-    if (::sqlite3_column_type(stmt_.get(), col) != SQLITE_TEXT)
-      throw std::invalid_argument{"invalid type for scan"};
-    unsigned char const* chs = ::sqlite3_column_text(stmt_.get(), col);
-    auto size = util::size_from_int(::sqlite3_column_bytes(stmt_.get(), col));
-    if (!size.has_value())
-      throw std::logic_error{"unexpected negative amount of bytes in column"};
-    s = std::string{reinterpret_cast<char const*>(chs), *size};
-  }
+  auto is_null(int col) -> bool;
+  auto ncols() -> std::size_t;
 
-  void scan(int col, double& v)
+  auto scan(int col, std::string& s) -> void;
+  auto scan(int col, double& v) -> void;
+  auto scan(int col, std::int64_t& v) -> void;
+  auto scan(int col, optional_of<scannable> auto& v) -> void
   {
-    if (::sqlite3_column_type(stmt_.get(), col) != SQLITE_FLOAT)
-      throw std::invalid_argument{"invalid type for scan"};
-    v = ::sqlite3_column_double(stmt_.get(), col);
-  }
-
-  void scan(int col, std::int64_t& v)
-  {
-    if (::sqlite3_column_type(stmt_.get(), col) != SQLITE_INTEGER)
-      throw std::invalid_argument{"invalid type for scan"};
-    v = ::sqlite3_column_int64(stmt_.get(), col);
-  }
-
-  void scan(int col, optional_of<scannable> auto& v)
-  {
-    if (::sqlite3_column_type(stmt_.get(), col) == SQLITE_NULL)
+    if (is_null(col))
     {
       v.reset();
     }
@@ -139,28 +96,11 @@ class row_reader
   }
 
 public:
-  auto next() -> bool
-  {
-    ::sqlite3* dbc = ::sqlite3_db_handle(stmt_.get());
-    return do_guarded(
-        dbc,
-        [&](auto const& guard) -> bool
-        {
-          auto const s = ::sqlite3_step(stmt_.get());
-          if (s == SQLITE_ROW)
-            return true;
-          if (s == SQLITE_DONE)
-            return false;
-          throw error{guard, s, dbc};
-        });
-  }
+  auto next() -> bool;
 
   auto scan(scannable auto&... args) -> void
   {
-    auto const ncols = util::size_from_int(::sqlite3_data_count(stmt_.get()));
-    if (!ncols.has_value())
-      throw std::logic_error{"got unexpected negative amount of columns"};
-    if (sizeof...(args) > *ncols)
+    if (sizeof...(args) > ncols())
       throw std::invalid_argument{
         "more scanning arguments provided than columns in result set"
       };
@@ -184,30 +124,14 @@ class binder
 {
   statement& stmt_;
 
-  explicit binder(statement& stmt) : stmt_{stmt} {}
+  explicit binder(statement& stmt);
 
   friend class connection;
 
 public:
-  auto text(std::string const& param_name, std::string_view str) -> void
-  {
-    int const i =
-        ::sqlite3_bind_parameter_index(stmt_.get(), param_name.c_str());
-    if (i == 0)
-      throw std::invalid_argument{std::format(
-          "bind: no parameter with name {} found", param_name)};
-    auto str_size = util::int_from_size(str.size());
-    if (!str_size.has_value())
-      throw std::invalid_argument{"bind: provided text is too long"};
-    if (auto s = ::sqlite3_bind_text(
-            stmt_.get(), i, str.data(), *str_size, SQLITE_TRANSIENT);
-        s != SQLITE_OK)
-    {
-      throw error{s};
-    }
-  }
+  auto text(std::string const& param_name, std::string_view str) -> void;
 
-  static auto noop(binder&) -> void {}
+  static auto noop(binder&) -> void;
 };
 
 export class connection
@@ -215,97 +139,25 @@ export class connection
   ::sqlite3* dbc_;
   ::sqlite3_mutex* mut_;
 
-  explicit connection(::sqlite3* dbc) : dbc_{dbc}, mut_{::sqlite3_db_mutex(dbc)}
-  {
-  }
+  explicit connection(::sqlite3* dbc);
 
   friend auto open(std::string const& filename) -> connection;
 
 public:
   connection(connection const&) = delete;
-  connection(connection&& c) noexcept
-  {
-    dbc_ = c.dbc_;
-    mut_ = c.mut_;
-    c.dbc_ = nullptr;
-    c.mut_ = nullptr;
-  }
+  connection(connection&& c) noexcept;
 
   [[nodiscard]] auto query(
       std::string const& sql,
-      std::function<void(binder&)> const& bf = binder::noop) -> row_reader
-  {
-    ::sqlite3_stmt* pstmt = nullptr;
-    char const* sql_tail = nullptr;
-    auto sql_size = util::int_from_size(sql.size());
-    if (!sql_size.has_value()
-        || *sql_size >= std::numeric_limits<int>::max() - 1)
-      throw std::invalid_argument{"provided input text too large"};
-    do_guarded(
-        mut_,
-        [&](auto const& guard) -> void
-        {
-          if (auto s = ::sqlite3_prepare_v2(
-                  dbc_, sql.data(), *sql_size + 1, &pstmt, &sql_tail);
-              s != SQLITE_OK)
-          {
-            if (pstmt != nullptr)
-            {
-              // Use contract_assert when having a compiler with
-              // contracts available
-              ::sqlite3_finalize(pstmt);
-              throw std::logic_error{
-                "expected stmt to be null after failed preparation"
-              };
-            }
-            throw error{guard, s, dbc_};
-          }
-        });
-    if (!pstmt)
-      throw std::invalid_argument{"provided input text contains no SQL"};
-    auto stmt = statement{pstmt};
-    if (sql_tail && std::strlen(sql_tail) > 0)
-      throw std::invalid_argument{
-        "provided input text contains more than one SQL statement"
-      };
-    auto b = binder{stmt};
-    bf(b);
-    return row_reader{std::move(stmt)};
-  }
+      std::function<void(binder&)> const& bf = binder::noop) -> row_reader;
 
   auto exec(
       std::string const& sql,
-      std::function<void(binder&)> const& bf = binder::noop) -> void
-  {
-    auto reader = query(sql, bf);
-    while (reader.next())
-      ;
-  }
+      std::function<void(binder&)> const& bf = binder::noop) -> void;
 
-  ~connection() { std::ignore = ::sqlite3_close(std::exchange(dbc_, nullptr)); }
+  ~connection();
 };
 
-export auto open(std::string const& filename) -> connection
-{
-  ::sqlite3* dbc = nullptr;
-  auto s = ::sqlite3_open_v2(
-      filename.c_str(), &dbc,
-      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | SQLITE_OPEN_FULLMUTEX
-          | SQLITE_OPEN_EXRESCODE,
-      nullptr);
-  if (s != SQLITE_OK)
-  {
-    if (dbc)
-    {
-      do_guarded(
-          dbc, [&](auto const& guard) -> void { throw error{guard, s, dbc}; });
-    }
-    else
-    {
-      throw error{s};
-    }
-  }
-  return connection{dbc};
-}
+export auto open(std::string const& filename) -> connection;
 
 } // namespace routemon::sqlite3
diff --git a/server/src/srv.cpp b/server/src/srv.cpp
new file mode 100644
index 0000000..00a2bb8
--- /dev/null
+++ b/server/src/srv.cpp
@@ -0,0 +1,258 @@
+module;
+
+#include <boost/asio/as_tuple.hpp>
+#include <boost/asio/awaitable.hpp>
+#include <boost/asio/co_spawn.hpp>
+#include <boost/asio/ip/tcp.hpp>
+#include <boost/beast/core.hpp>
+#include <boost/beast/http.hpp>
+#include <boost/config.hpp>
+#include <boost/json.hpp>
+#include <boost/locale/generator.hpp>
+
+#include <expat.h>
+
+module routemon:srv$impl;
+
+import std;
+import :gpx;
+import :srv;
+
+namespace beast = boost::beast;
+namespace json = boost::json;
+namespace net = boost::asio;
+using tcp = boost::asio::ip::tcp;
+
+namespace routemon::srv {
+
+class gpx_parse_error_category_impl : public std::error_category
+{
+public:
+  char const* name() const noexcept override { return "gpx_parse"; }
+
+  auto message(int condition) const noexcept -> std::string override
+  {
+    std::ignore = condition;
+    return "failed to parse GPX file";
+  }
+};
+
+auto gpx_parse_error_category() noexcept -> gpx_parse_error_category_impl const&
+{
+  static auto const inst = gpx_parse_error_category_impl{};
+  return inst;
+}
+
+auto gpx_parse_error() noexcept -> std::error_code
+{
+  return std::error_code{1, gpx_parse_error_category()};
+}
+
+class gpx_parse_result
+{
+  std::variant<std::exception_ptr, gpx::file> res_;
+
+public:
+  auto set_exception(std::exception_ptr ex) noexcept { res_ = ex; }
+  auto set_gpx_file(gpx::file&& f) noexcept { res_ = std::move(f); }
+
+  auto unwrap() -> gpx::file&&
+  {
+    return std::visit(
+        util::overloaded{
+          [](std::exception_ptr ex) -> gpx::file&&
+          {
+            if (ex)
+              std::rethrow_exception(ex);
+            else
+              throw std::runtime_error{"no GPX file parse result available"};
+          },
+          [](gpx::file&& f) -> gpx::file&& { return std::move(f); },
+        },
+        std::move(res_));
+  }
+};
+
+struct readable_gpx_body
+{
+  using value_type = gpx_parse_result;
+
+  class reader
+  {
+    gpx::reader r_;
+    util::not_null<value_type*> res_;
+
+  public:
+    template <bool isRequest, bhttp::concepts::fields Fields>
+    explicit reader(bhttp::header<isRequest, Fields>&, value_type& v) : res_{&v}
+    {
+    }
+
+    // The following methods (which are called by Beast) are marked
+    // noexcept, since Beast does not ensure that exceptions thrown
+    // here are appropriately directed to the caller of
+    // (async_)read(_some), so throwing here might cause the program
+    // to crash.
+
+    auto
+    init(boost::optional<std::uint64_t> /* n */, beast::error_code& ec) noexcept
+        -> void
+    {
+      try
+      {
+        r_.init();
+        ec = {};
+      }
+      catch (std::exception& ex)
+      {
+        res_->set_exception(std::current_exception());
+        ec = gpx_parse_error();
+      }
+    }
+
+    auto
+    put(beast::concepts::const_buffer_sequence auto b,
+        beast::error_code& ec) noexcept -> std::size_t
+    {
+      auto total = 0uz;
+      try
+      {
+        for (auto it = net::buffer_sequence_begin(b);
+             it != net::buffer_sequence_end(b); it++)
+        {
+          r_.put(
+              std::string_view{
+                static_cast<char const*>(it->data()), it->size()
+              });
+          total += it->size();
+        }
+        ec = {};
+      }
+      catch (std::exception& ex)
+      {
+        res_->set_exception(std::current_exception());
+        ec = gpx_parse_error();
+      }
+      return total;
+    }
+
+    auto finish(beast::error_code& ec) noexcept
+    {
+      try
+      {
+        res_->set_gpx_file(r_.finish());
+        ec = {};
+      }
+      catch (std::exception& ex)
+      {
+        res_->set_exception(std::current_exception());
+        ec = gpx_parse_error();
+      }
+    }
+  };
+};
+static_assert(bhttp::concepts::body<readable_gpx_body>);
+static_assert(bhttp::concepts::body_reader<readable_gpx_body>);
+
+auto handler::handle_process_gpx(l0_ctx ctx, http::readable_request r)
+    -> net::awaitable<http::presponse>
+{
+  auto gpx_file = gpx::file{};
+  try
+  {
+    auto req =
+        co_await http::read_request<readable_gpx_body>(ctx, std::move(r));
+    gpx_file = std::move(req->body().unwrap());
+  }
+  catch (std::exception& ex)
+  {
+    // TODO: more detailed problem reporting
+    auto tpl = problem::tpl{
+      .status = bhttp::status::bad_request,
+      .title = translate("Failed to parse GPX file"),
+      .type_uri = "https://routemon.fautchen.eu/problems/gpx-parse-failed",
+    };
+    co_return http::problem_rsp(
+        ctx, tpl.instantiate(), http::keep_alive{false});
+  }
+
+  // TODO: catch handler exceptions and return 500 when raised?
+  // (keep-alive depends on whether whole request was read)
+  auto mres = inner_.process_gpx(std::move(gpx_file));
+  if (!mres)
+  {
+    auto tpl = problem::tpl{
+      .status = bhttp::status::internal_server_error,
+      .title = translate("Internal server error"),
+      .type_uri = "https://routemon.fautchen.eu/problems/"
+                  "internal-server-error",
+    };
+    co_return http::problem_rsp(ctx, tpl.instantiate(), http::keep_alive{true});
+  }
+
+  auto rsp = http::make_rsp<bhttp::string_body>(
+      bhttp::status::ok, http::keep_alive{true});
+  rsp.set(bhttp::field::content_type, "application/json");
+  rsp.body() = json::serialize(json::value_from(*mres));
+  rsp.prepare_payload();
+  co_return rsp;
+}
+
+auto handler::handle_sysinfo(l0_ctx ctx, http::readable_request r)
+    -> net::awaitable<http::presponse>
+{
+  auto req = co_await http::read_request<bhttp::empty_body>(ctx, std::move(r));
+  auto info = inner_.sysinfo();
+
+  auto rsp = http::make_rsp<bhttp::string_body>(
+      bhttp::status::ok, http::keep_alive{true});
+  rsp.set(bhttp::field::content_type, "application/json");
+  rsp.body() = json::serialize(json::value_from(info));
+  rsp.prepare_payload();
+  co_return rsp;
+}
+
+handler::handler(api::handler&& inner) : inner_{std::move(inner)} {}
+
+auto handler::make_routes() -> http::route_tree<http::routed_ctx<outer_ctx>>
+{
+  auto handler = [this]<class MemFn>(MemFn member)
+  { return std::bind_front(member, this); };
+
+  return http::dtree<http::routed_ctx<outer_ctx>>{}.named_subtrees({
+    {"gpx", http::dtree<l0_ctx>{{
+                                  .post = handler(&handler::handle_process_gpx),
+                                }}
+                .no_subtrees()},
+    {"sysinfo", http::dtree<l0_ctx>{
+                  {
+                    .get = handler(&handler::handle_sysinfo),
+                  }
+                }.no_subtrees()},
+  });
+}
+
+auto server::make_global_middleware()
+    -> http::middleware_t<http::base_ctx, handler::outer_ctx>
+{
+  return http::middleware_compose<
+      http::base_ctx, http::trace_id_ctx<http::base_ctx>,
+      http::trace_id_ctx<http::base_ctx>
+  >(http::trace_id_middleware<http::base_ctx>,
+    http::lax_cors_middleware<http::trace_id_ctx<http::base_ctx>>);
+}
+
+server::server(
+    log::logger const& l, locale::selector&& lsel, api::handler&& inner)
+  : handler_{std::move(inner)},
+    srv_{
+      l, http::router{
+           std::move(lsel), make_global_middleware(), handler_.make_routes()
+         }
+    }
+{
+}
+
+auto server::spawn(net::io_context& ioc) -> void { srv_.spawn(ioc); }
+
+} // namespace routemon::srv
diff --git a/server/src/srv.cppm b/server/src/srv.cppm
index 904bf1a..1d082fb 100644
--- a/server/src/srv.cppm
+++ b/server/src/srv.cppm
@@ -1,166 +1,14 @@
 module;
 
-#include <boost/asio/as_tuple.hpp>
 #include <boost/asio/awaitable.hpp>
-#include <boost/asio/co_spawn.hpp>
-#include <boost/asio/ip/tcp.hpp>
-#include <boost/beast/core.hpp>
-#include <boost/beast/http.hpp>
-#include <boost/config.hpp>
-#include <boost/json.hpp>
-#include <boost/locale/generator.hpp>
-
-#include <expat.h>
 
 export module routemon:srv;
 
-import std;
 import :api;
-import :config;
-import :gpx;
 import :http.server;
-import :locale;
-import :log;
-import :problem;
-import :req_ctx;
-import :util;
-
-namespace beast = boost::beast;
-namespace json = boost::json;
-namespace net = boost::asio;
-using tcp = boost::asio::ip::tcp;
 
 namespace routemon::srv {
 
-class gpx_parse_error_category_impl : public std::error_category
-{
-public:
-  char const* name() const noexcept override { return "gpx_parse"; }
-
-  auto message(int condition) const noexcept -> std::string override
-  {
-    std::ignore = condition;
-    return "failed to parse GPX file";
-  }
-};
-
-auto gpx_parse_error_category() noexcept -> gpx_parse_error_category_impl const&
-{
-  static auto const inst = gpx_parse_error_category_impl{};
-  return inst;
-}
-
-auto gpx_parse_error() noexcept -> std::error_code
-{
-  return std::error_code{1, gpx_parse_error_category()};
-}
-
-class gpx_parse_result
-{
-  std::variant<std::exception_ptr, gpx::file> res_;
-
-public:
-  auto set_exception(std::exception_ptr ex) noexcept { res_ = ex; }
-  auto set_gpx_file(gpx::file&& f) noexcept { res_ = std::move(f); }
-
-  auto unwrap() -> gpx::file&&
-  {
-    return std::visit(
-        util::overloaded{
-          [](std::exception_ptr ex) -> gpx::file&&
-          {
-            if (ex)
-              std::rethrow_exception(ex);
-            else
-              throw std::runtime_error{"no GPX file parse result available"};
-          },
-          [](gpx::file&& f) -> gpx::file&& { return std::move(f); },
-        },
-        std::move(res_));
-  }
-};
-
-struct readable_gpx_body
-{
-  using value_type = gpx_parse_result;
-
-  class reader
-  {
-    gpx::reader r_;
-    util::not_null<value_type*> res_;
-
-  public:
-    template <bool isRequest, bhttp::concepts::fields Fields>
-    explicit reader(bhttp::header<isRequest, Fields>&, value_type& v) : res_{&v}
-    {
-    }
-
-    // The following methods (which are called by Beast) are marked
-    // noexcept, since Beast does not ensure that exceptions thrown
-    // here are appropriately directed to the caller of
-    // (async_)read(_some), so throwing here might cause the program
-    // to crash.
-
-    auto
-    init(boost::optional<std::uint64_t> /* n */, beast::error_code& ec) noexcept
-        -> void
-    {
-      try
-      {
-        r_.init();
-        ec = {};
-      }
-      catch (std::exception& ex)
-      {
-        res_->set_exception(std::current_exception());
-        ec = gpx_parse_error();
-      }
-    }
-
-    auto
-    put(beast::concepts::const_buffer_sequence auto b,
-        beast::error_code& ec) noexcept -> std::size_t
-    {
-      auto total = 0uz;
-      try
-      {
-        for (auto it = net::buffer_sequence_begin(b);
-             it != net::buffer_sequence_end(b); it++)
-        {
-          r_.put(
-              std::string_view{
-                static_cast<char const*>(it->data()), it->size()
-              });
-          total += it->size();
-        }
-        ec = {};
-      }
-      catch (std::exception& ex)
-      {
-        res_->set_exception(std::current_exception());
-        ec = gpx_parse_error();
-      }
-      return total;
-    }
-
-    auto finish(beast::error_code& ec) noexcept
-    {
-      try
-      {
-        res_->set_gpx_file(r_.finish());
-        ec = {};
-      }
-      catch (std::exception& ex)
-      {
-        res_->set_exception(std::current_exception());
-        ec = gpx_parse_error();
-      }
-    }
-  };
-};
-static_assert(bhttp::concepts::body<readable_gpx_body>);
-static_assert(bhttp::concepts::body_reader<readable_gpx_body>);
-
 class handler
 {
   api::handler inner_;
@@ -171,112 +19,29 @@ public:
 
 private:
   auto handle_process_gpx(l0_ctx ctx, http::readable_request r)
-      -> net::awaitable<http::presponse>
-  {
-    auto gpx_file = gpx::file{};
-    try
-    {
-      auto req =
-          co_await http::read_request<readable_gpx_body>(ctx, std::move(r));
-      gpx_file = std::move(req->body().unwrap());
-    }
-    catch (std::exception& ex)
-    {
-      // TODO: more detailed problem reporting
-      auto tpl = problem::tpl{
-        .status = bhttp::status::bad_request,
-        .title = translate("Failed to parse GPX file"),
-        .type_uri = "https://routemon.fautchen.eu/problems/gpx-parse-failed",
-      };
-      co_return http::problem_rsp(
-          ctx, tpl.instantiate(), http::keep_alive{false});
-    }
-
-    // TODO: catch handler exceptions and return 500 when raised?
-    // (keep-alive depends on whether whole request was read)
-    auto mres = inner_.process_gpx(std::move(gpx_file));
-    if (!mres)
-    {
-      auto tpl = problem::tpl{
-        .status = bhttp::status::internal_server_error,
-        .title = translate("Internal server error"),
-        .type_uri = "https://routemon.fautchen.eu/problems/"
-                    "internal-server-error",
-      };
-      co_return http::problem_rsp(
-          ctx, tpl.instantiate(), http::keep_alive{true});
-    }
-
-    auto rsp = http::make_rsp<bhttp::string_body>(
-        bhttp::status::ok, http::keep_alive{true});
-    rsp.set(bhttp::field::content_type, "application/json");
-    rsp.body() = json::serialize(json::value_from(*mres));
-    rsp.prepare_payload();
-    co_return rsp;
-  }
+      -> net::awaitable<http::presponse>;
 
   auto handle_sysinfo(l0_ctx ctx, http::readable_request r)
-      -> net::awaitable<http::presponse>
-  {
-    auto req =
-        co_await http::read_request<bhttp::empty_body>(ctx, std::move(r));
-    auto info = inner_.sysinfo();
-
-    auto rsp = http::make_rsp<bhttp::string_body>(
-        bhttp::status::ok, http::keep_alive{true});
-    rsp.set(bhttp::field::content_type, "application/json");
-    rsp.body() = json::serialize(json::value_from(info));
-    rsp.prepare_payload();
-    co_return rsp;
-  }
+      -> net::awaitable<http::presponse>;
 
 public:
-  handler(api::handler&& inner) : inner_{std::move(inner)} {}
-
-  auto make_routes() -> http::route_tree<http::routed_ctx<outer_ctx>>
-  {
-    auto handler = [this]<class MemFn>(MemFn member)
-    { return std::bind_front(member, this); };
+  handler(api::handler&& inner);
 
-    return http::dtree<http::routed_ctx<outer_ctx>>{}.named_subtrees({
-      {"gpx",
-       http::dtree<l0_ctx>{
-         {
-           .post = handler(&handler::handle_process_gpx),
-         }
-       }.no_subtrees()},
-      {"sysinfo", http::dtree<l0_ctx>{
-                    {
-                      .get = handler(&handler::handle_sysinfo),
-                    }
-                  }.no_subtrees()},
-    });
-  }
+  auto make_routes() -> http::route_tree<http::routed_ctx<outer_ctx>>;
 };
 
 export class server
 {
   handler handler_;
-  http::server<handler::outer_ctx> srv_;
+  http::server srv_;
 
   static auto make_global_middleware()
-      -> http::middleware_t<http::base_ctx, handler::outer_ctx>
-  {
-    return http::middleware_compose<
-        http::base_ctx, http::trace_id_ctx<http::base_ctx>,
-        http::trace_id_ctx<http::base_ctx>>(
-        http::trace_id_middleware<http::base_ctx>,
-        http::lax_cors_middleware<http::trace_id_ctx<http::base_ctx>>);
-  }
+      -> http::middleware_t<http::base_ctx, handler::outer_ctx>;
 
 public:
-  server(log::logger const& l, locale::selector&& lsel, api::handler&& inner)
-    : handler_{std::move(inner)},
-      srv_{l, std::move(lsel), make_global_middleware(), handler_.make_routes()}
-  {
-  }
+  server(log::logger const& l, locale::selector&& lsel, api::handler&& inner);
 
-  auto spawn(net::io_context& ioc) -> void { srv_.spawn(ioc); }
+  auto spawn(net::io_context& ioc) -> void;
 };
 
 } // namespace routemon::srv
diff --git a/server/src/time.cpp b/server/src/time.cpp
new file mode 100644
index 0000000..8f99dd2
--- /dev/null
+++ b/server/src/time.cpp
@@ -0,0 +1,173 @@
+module routemon:time$impl;
+
+import :time;
+
+export namespace routemon::time {
+
+using timestamp = std::chrono::time_point<std::chrono::utc_clock>;
+
+period::period(timestamp start, timestamp end) : start_{start}, end_{end}
+{
+  if (start >= end)
+  {
+    throw std::invalid_argument("period: start should be before end");
+  }
+}
+
+auto period::intersect(period other) const -> std::optional<period>
+{
+  auto const new_start = start_ < other.start() ? other.start() : start_;
+  auto const new_end = other.end() < end_ ? other.end() : end_;
+  return new_start < new_end ? std::make_optional(period{new_start, new_end})
+                             : std::nullopt;
+}
+
+auto period::except(period other) const
+    -> std::pair<std::optional<period>, std::optional<period>>
+{
+  auto const before_start = start_;
+  auto const before_end = other.start();
+  auto const after_start = end_;
+  auto const after_end = other.end();
+  std::optional<period> before, after;
+  if (before_start < before_end)
+    before = period{before_start, before_end};
+  if (after_start < after_end)
+    after = period{after_end, after_start};
+  return std::make_pair(before, after);
+}
+
+auto period::start() const -> timestamp { return start_; }
+auto period::end() const -> timestamp { return end_; }
+
+period_seq::period_seq(std::vector<period> periods)
+  : periods_{std::move(periods)}
+{
+  for (auto i = 0uz; i < periods_.size(); i++)
+  {
+    if (i + 1 < periods_.size())
+    {
+      if (periods_[i].end() >= periods_[i + 1].start())
+      {
+        throw std::logic_error{"period_seq: vector provided to private "
+                               "constructor not ordered properly"};
+      }
+    }
+  }
+}
+
+period_seq::period_seq(period singleton) : periods_{singleton} {}
+
+auto period_seq::intersect(period_seq const& other) const -> period_seq
+{
+  auto it1 = periods_.begin();
+  auto end1 = periods_.end();
+  auto it2 = other.periods_.begin();
+  auto end2 = other.periods_.end();
+
+  auto res = std::vector<period>{};
+  while (it1 != end1 && it2 != end2)
+  {
+    auto overlap = it1->intersect(*it2);
+    if (overlap)
+    {
+      res.push_back(*overlap);
+      if (it1->end() < it2->end())
+      {
+        it1++;
+      }
+      else
+      {
+        it2++;
+      }
+    }
+    else
+    {
+      if (it1->end() < it2->start())
+      {
+        it1++;
+      }
+      else
+      {
+        it2++;
+      }
+    }
+  }
+
+  return period_seq{res};
+}
+
+auto period_seq::except(period_seq const& other) const -> period_seq
+{
+  // This code was pretty tricky to write, I wouldn't be surprised if it
+  // has some bugs in it.
+
+  auto it1 = periods_.begin();
+  auto end1 = periods_.end();
+  auto it2 = other.periods_.begin();
+  auto end2 = other.periods_.end();
+
+  auto res = std::vector<period>{};
+  if (it1 == end1)
+    return period_seq{res};
+  if (it2 == end2)
+    return period_seq{periods_};
+  auto period1 = period{*it1++};
+
+  while (it1 != end1 && it2 != end2)
+  {
+    if (period1.end() <= it2->start())
+    {
+      res.push_back(period1);
+      period1 = *it1++;
+    }
+    else if (it2->end() <= period1.start())
+    {
+      it2++;
+    }
+    else /* period1.begin() < it2->end() && it2->begin() <
+            period1.end() */
+    {
+      auto const [mbefore, mafter] = period1.except(*it2);
+      if (mbefore)
+        res.push_back(*mbefore);
+      if (mafter)
+      {
+        period1 = *mafter;
+      }
+      else
+      {
+        period1 = *it1++;
+      }
+    }
+  }
+
+  return period_seq{res};
+}
+
+auto period_seq::periods() const -> std::vector<period> const&
+{
+  return periods_;
+}
+
+auto operator<<(std::ostream& os, period const& p) -> std::ostream&
+{
+  return os << "[" << p.start() << ", " << p.end() << ")";
+}
+
+auto operator<<(std::ostream& os, period_seq const& ps) -> std::ostream&
+{
+  os << "{";
+  auto it = ps.periods().begin();
+  while (it != ps.periods().end())
+  {
+    os << " " << *it;
+    if (++it != ps.periods().end())
+    {
+      os << ",";
+    }
+  }
+  return os << " }";
+}
+
+} // namespace routemon::time
diff --git a/server/src/time.cppm b/server/src/time.cppm
index 8f53bd9..0007839 100644
--- a/server/src/time.cppm
+++ b/server/src/time.cppm
@@ -14,39 +14,13 @@ class period
   timestamp end_;
 
 public:
-  explicit period(timestamp start, timestamp end) : start_{start}, end_{end}
-  {
-    if (start >= end)
-    {
-      throw std::invalid_argument("period: start should be before end");
-    }
-  }
-
-  [[nodiscard]] auto intersect(period other) const -> std::optional<period>
-  {
-    auto const new_start = start_ < other.start() ? other.start() : start_;
-    auto const new_end = other.end() < end_ ? other.end() : end_;
-    return new_start < new_end ? std::make_optional(period{new_start, new_end})
-                               : std::nullopt;
-  }
+  explicit period(timestamp start, timestamp end);
 
+  [[nodiscard]] auto intersect(period other) const -> std::optional<period>;
   [[nodiscard]] auto except(period other) const
-      -> std::pair<std::optional<period>, std::optional<period>>
-  {
-    auto const before_start = start_;
-    auto const before_end = other.start();
-    auto const after_start = end_;
-    auto const after_end = other.end();
-    std::optional<period> before, after;
-    if (before_start < before_end)
-      before = period{before_start, before_end};
-    if (after_start < after_end)
-      after = period{after_end, after_start};
-    return std::make_pair(before, after);
-  }
-
-  [[nodiscard]] auto start() const -> timestamp { return start_; }
-  [[nodiscard]] auto end() const -> timestamp { return end_; }
+      -> std::pair<std::optional<period>, std::optional<period>>;
+  [[nodiscard]] auto start() const -> timestamp;
+  [[nodiscard]] auto end() const -> timestamp;
 };
 
 class period_seq
@@ -115,21 +89,7 @@ class period_seq
     return periods;
   }
 
-  explicit period_seq(std::vector<period> periods)
-    : periods_{std::move(periods)}
-  {
-    for (auto i = 0uz; i < periods_.size(); i++)
-    {
-      if (i + 1 < periods_.size())
-      {
-        if (periods_[i].end() >= periods_[i + 1].start())
-        {
-          throw std::logic_error{"period_seq: vector provided to private "
-                                 "constructor not ordered properly"};
-        }
-      }
-    }
-  }
+  explicit period_seq(std::vector<period> periods);
 
 public:
   template <std::input_iterator I, std::sentinel_for<I> S>
@@ -138,119 +98,14 @@ public:
   {
   }
 
-  explicit period_seq(period singleton) : periods_{singleton} {}
-
-  [[nodiscard]] auto intersect(period_seq const& other) const -> period_seq
-  {
-    auto it1 = periods_.begin();
-    auto end1 = periods_.end();
-    auto it2 = other.periods_.begin();
-    auto end2 = other.periods_.end();
-
-    auto res = std::vector<period>{};
-    while (it1 != end1 && it2 != end2)
-    {
-      auto overlap = it1->intersect(*it2);
-      if (overlap)
-      {
-        res.push_back(*overlap);
-        if (it1->end() < it2->end())
-        {
-          it1++;
-        }
-        else
-        {
-          it2++;
-        }
-      }
-      else
-      {
-        if (it1->end() < it2->start())
-        {
-          it1++;
-        }
-        else
-        {
-          it2++;
-        }
-      }
-    }
-
-    return period_seq{res};
-  }
-
-  [[nodiscard]] auto except(period_seq const& other) const -> period_seq
-  {
-    // This code was pretty tricky to write, I wouldn't be surprised if it
-    // has some bugs in it.
-
-    auto it1 = periods_.begin();
-    auto end1 = periods_.end();
-    auto it2 = other.periods_.begin();
-    auto end2 = other.periods_.end();
-
-    auto res = std::vector<period>{};
-    if (it1 == end1)
-      return period_seq{res};
-    if (it2 == end2)
-      return period_seq{periods_};
-    auto period1 = period{*it1++};
-
-    while (it1 != end1 && it2 != end2)
-    {
-      if (period1.end() <= it2->start())
-      {
-        res.push_back(period1);
-        period1 = *it1++;
-      }
-      else if (it2->end() <= period1.start())
-      {
-        it2++;
-      }
-      else /* period1.begin() < it2->end() && it2->begin() <
-              period1.end() */
-      {
-        auto const [mbefore, mafter] = period1.except(*it2);
-        if (mbefore)
-          res.push_back(*mbefore);
-        if (mafter)
-        {
-          period1 = *mafter;
-        }
-        else
-        {
-          period1 = *it1++;
-        }
-      }
-    }
-
-    return period_seq{res};
-  }
+  explicit period_seq(period singleton);
 
-  [[nodiscard]] auto periods() const -> std::vector<period> const&
-  {
-    return periods_;
-  }
+  [[nodiscard]] auto intersect(period_seq const& other) const -> period_seq;
+  [[nodiscard]] auto except(period_seq const& other) const -> period_seq;
+  [[nodiscard]] auto periods() const -> std::vector<period> const&;
 };
 
-auto operator<<(std::ostream& os, period const& p) -> std::ostream&
-{
-  return os << "[" << p.start() << ", " << p.end() << ")";
-}
-
-auto operator<<(std::ostream& os, period_seq const& ps) -> std::ostream&
-{
-  os << "{";
-  auto it = ps.periods().begin();
-  while (it != ps.periods().end())
-  {
-    os << " " << *it;
-    if (++it != ps.periods().end())
-    {
-      os << ",";
-    }
-  }
-  return os << " }";
-}
+auto operator<<(std::ostream& os, period const& p) -> std::ostream&;
+auto operator<<(std::ostream& os, period_seq const& ps) -> std::ostream&;
 
 } // namespace routemon::time
diff --git a/server/src/trace.cpp b/server/src/trace.cpp
new file mode 100644
index 0000000..e7c00d0
--- /dev/null
+++ b/server/src/trace.cpp
@@ -0,0 +1,75 @@
+module;
+
+// Might as well since we're using OpenSSL
+#include <openssl/err.h>
+#include <openssl/rand.h>
+
+module routemon:trace$impl;
+
+import :trace;
+
+namespace routemon::trace {
+
+uuid7::uuid7()
+{
+  namespace chrono = std::chrono;
+  auto const unix_time_ms_signed = static_cast<std::int64_t>(
+      chrono::duration_cast<chrono::milliseconds>(
+          chrono::system_clock::now().time_since_epoch())
+          .count());
+  if (unix_time_ms_signed < 0)
+    throw std::runtime_error{"system time before UNIX epoch"};
+  auto const unix_time_ms = static_cast<std::uint64_t>(unix_time_ms_signed);
+  if (std::countl_zero(unix_time_ms) < 16)
+    throw std::runtime_error{"system time too great"};
+
+  auto rand = std::array<unsigned char, 10>{};
+  int s = RAND_bytes(rand.data(), static_cast<int>(rand.size()));
+  if (s != 1)
+  {
+    unsigned long e = ERR_get_error();
+    throw std::runtime_error{std::format(
+        "failed to generate UUID(v7): {} ({}, code {})",
+        ERR_reason_error_string(e), ERR_lib_error_string(e), e)};
+  }
+
+  auto version = std::uint64_t{0b0111};
+  auto variant = std::uint64_t{0b10};
+
+  hi_ |= unix_time_ms << 16;
+  hi_ |= version << 12;
+  hi_ |= std::uint64_t{rand[0]} << 4;
+  hi_ |= std::uint64_t{rand[1]};
+  lo_ |= variant << 62;
+  lo_ |= std::uint64_t{rand[2]} << 54;
+  lo_ |= std::uint64_t{rand[3]} << 48;
+  lo_ |= std::uint64_t{rand[4]} << 40;
+  lo_ |= std::uint64_t{rand[5]} << 32;
+  lo_ |= std::uint64_t{rand[6]} << 24;
+  lo_ |= std::uint64_t{rand[7]} << 16;
+  lo_ |= std::uint64_t{rand[8]} << 8;
+  lo_ |= std::uint64_t{rand[9]};
+}
+
+auto uuid7::format(std::array<char, 37>& target) -> void
+{
+  auto p____hi_hi = (hi_ & 0xffff'ffff'0000'0000) >> 32;
+  auto p_hi_lo_hi = (hi_ & 0x0000'0000'ffff'0000) >> 16;
+  auto p_lo_lo_hi = (hi_ & 0x0000'0000'0000'ffff) >> 0;
+  auto p____hi_lo = (lo_ & 0xffff'0000'0000'0000) >> 48;
+  auto p____lo_lo = (lo_ & 0x0000'ffff'ffff'ffff) >> 0;
+
+  std::format_to(
+      target.begin(), "{:0>8x}-{:0>4x}-{:0>4x}-{:0>4x}-{:0>12x}", p____hi_hi,
+      p_hi_lo_hi, p_lo_lo_hi, p____hi_lo, p____lo_lo);
+  target.back() = '\0';
+}
+
+id::id() { uuid7{}.format(chars_); }
+
+auto id::as_string() const -> util::zstring_view
+{
+  return util::zstring_view{chars_.data(), chars_.size() - 1};
+}
+
+} // namespace routemon::trace
diff --git a/server/src/trace.cppm b/server/src/trace.cppm
index 35d32f3..deb84a0 100644
--- a/server/src/trace.cppm
+++ b/server/src/trace.cppm
@@ -1,9 +1,3 @@
-module;
-
-// Might as well since we're using OpenSSL
-#include <openssl/err.h>
-#include <openssl/rand.h>
-
 export module routemon:trace;
 
 import std;
@@ -13,64 +7,13 @@ namespace routemon::trace {
 
 class uuid7
 {
-  std::uint64_t high_ = 0;
-  std::uint64_t low_ = 0;
+  std::uint64_t hi_ = 0;
+  std::uint64_t lo_ = 0;
 
 public:
-  uuid7()
-  {
-    namespace chrono = std::chrono;
-    auto const unix_time_ms_signed = static_cast<std::int64_t>(
-        chrono::duration_cast<chrono::milliseconds>(
-            chrono::system_clock::now().time_since_epoch())
-            .count());
-    if (unix_time_ms_signed < 0)
-      throw std::runtime_error{"system time before UNIX epoch"};
-    auto const unix_time_ms = static_cast<std::uint64_t>(unix_time_ms_signed);
-    if (std::countl_zero(unix_time_ms) < 16)
-      throw std::runtime_error{"system time too great"};
-
-    auto rand = std::array<unsigned char, 10>{};
-    int s = RAND_bytes(rand.data(), static_cast<int>(rand.size()));
-    if (s != 1)
-    {
-      unsigned long e = ERR_get_error();
-      throw std::runtime_error{std::format(
-          "failed to generate UUID(v7): {} ({}, code {})",
-          ERR_reason_error_string(e), ERR_lib_error_string(e), e)};
-    }
-
-    auto version = std::uint64_t{0b0111};
-    auto variant = std::uint64_t{0b10};
-
-    high_ |= unix_time_ms << 16;
-    high_ |= version << 12;
-    high_ |= std::uint64_t{rand[0]} << 4;
-    high_ |= std::uint64_t{rand[1]};
-    low_ |= variant << 62;
-    low_ |= std::uint64_t{rand[2]} << 54;
-    low_ |= std::uint64_t{rand[3]} << 48;
-    low_ |= std::uint64_t{rand[4]} << 40;
-    low_ |= std::uint64_t{rand[5]} << 32;
-    low_ |= std::uint64_t{rand[6]} << 24;
-    low_ |= std::uint64_t{rand[7]} << 16;
-    low_ |= std::uint64_t{rand[8]} << 8;
-    low_ |= std::uint64_t{rand[9]};
-  }
-
-  auto format(std::array<char, 37>& target) -> void
-  {
-    auto high_high = (high_ & 0xffff'ffff'0000'0000) >> 32;
-    auto high_low_high = (high_ & 0x0000'0000'ffff'0000) >> 16;
-    auto low_low_high = (high_ & 0x0000'0000'0000'ffff) >> 0;
-    auto high_low = (low_ & 0xffff'0000'0000'0000) >> 48;
-    auto low_low = (low_ & 0x0000'ffff'ffff'ffff) >> 0;
+  uuid7();
 
-    std::format_to(
-        target.begin(), "{:0>8x}-{:0>4x}-{:0>4x}-{:0>4x}-{:0>12x}", high_high,
-        high_low_high, low_low_high, high_low, low_low);
-    target.back() = '\0';
-  }
+  auto format(std::array<char, 37>& target) -> void;
 };
 
 export class id
@@ -78,12 +21,9 @@ export class id
   std::array<char, 37> chars_;
 
 public:
-  id() { uuid7{}.format(chars_); }
+  id();
 
-  auto as_string() const -> util::zstring_view
-  {
-    return util::zstring_view{chars_.data(), chars_.size() - 1};
-  }
+  auto as_string() const -> util::zstring_view;
 };
 
 } // namespace routemon::trace
diff --git a/server/src/util.cpp b/server/src/util.cpp
new file mode 100644
index 0000000..54040a6
--- /dev/null
+++ b/server/src/util.cpp
@@ -0,0 +1,75 @@
+module routemon:util$impl;
+
+import :util;
+
+namespace routemon::util {
+
+lazy_zstring_view::lazy_zstring_view(lazy_zstring_view const& sv) noexcept
+  : s_{sv.s_}, length_{sv.length_.load(std::memory_order_acquire)}
+{
+}
+
+lazy_zstring_view::lazy_zstring_view(lazy_zstring_view&& sv) noexcept
+  : s_{sv.s_}, length_{sv.length_.load(std::memory_order_acquire)}
+{
+}
+
+auto lazy_zstring_view::operator=(lazy_zstring_view const& rhs) noexcept
+    -> lazy_zstring_view&
+{
+  if (this != &rhs)
+  {
+    s_ = rhs.s_;
+    length_.store(
+        rhs.length_.load(std::memory_order_acquire), std::memory_order_release);
+  }
+  return *this;
+}
+
+auto lazy_zstring_view::operator=(lazy_zstring_view&& rhs) noexcept
+    -> lazy_zstring_view&
+{
+  return *this = rhs; // use the copy assignment operator
+}
+
+auto lazy_zstring_view::length() const noexcept -> std::size_t
+{
+  if (auto v = length_.load(std::memory_order_acquire); v != unset_length)
+    return v;
+  auto l = std::char_traits<char>::length(s_);
+  length_.store(l, std::memory_order_release);
+  return l;
+}
+
+auto lazy_zstring_view::c_str() const noexcept -> char const* { return s_; }
+
+lazy_zstring_view::operator std::string_view() const noexcept
+{
+  return std::string_view{s_, length()};
+}
+
+lazy_zstring_view::operator char const*() const noexcept { return s_; }
+
+auto lazy_zstring_view::operator==(std::string_view sv) const noexcept -> bool
+{
+  if (auto v = length_.load(std::memory_order_acquire); v != unset_length)
+    if (sv.length() != v)
+      return false;
+  auto res = std::char_traits<char>::compare(s_, sv.data(), sv.length());
+  if (res != 0)
+    return false;
+  // Strings are equal for sv.length() characters.
+  if (s_[sv.length()] != '\0')
+    return false;
+  // Strings are actually equal, and we have just found out the
+  // length of this string, so we might as well set it.
+  length_.store(sv.length(), std::memory_order_release);
+  return true;
+}
+
+auto operator==(zstring_view lhs, zstring_view rhs) -> bool
+{
+  return std::string_view{lhs} == std::string_view{rhs};
+}
+
+} // namespace routemon::util
diff --git a/server/src/util.cppm b/server/src/util.cppm
index bdccf10..2857fe5 100644
--- a/server/src/util.cppm
+++ b/server/src/util.cppm
@@ -13,7 +13,7 @@ struct overloaded : Ts...
   using Ts::operator()...;
 };
 
-export constexpr auto parse_double(
+constexpr auto parse_double(
     std::string_view s,
     std::chars_format fmt = std::chars_format::general) noexcept
     -> std::optional<double>
@@ -30,7 +30,7 @@ export constexpr auto parse_double(
   }
 }
 
-export constexpr auto parse_float(
+constexpr auto parse_float(
     std::string_view s,
     std::chars_format fmt = std::chars_format::general) noexcept
     -> std::optional<float>
@@ -47,7 +47,7 @@ export constexpr auto parse_float(
   }
 }
 
-export template <class T>
+template <class T>
 class aolist : public std::enable_shared_from_this<aolist<T>>
 {
   T v_;
@@ -72,7 +72,7 @@ public:
   auto value() const noexcept -> T const& { return v_; }
 };
 
-export constexpr auto size_from_int(int x) -> std::optional<std::size_t>
+constexpr auto size_from_int(int x) -> std::optional<std::size_t>
 {
   static_assert(
       sizeof(int) <= sizeof(std::size_t),
@@ -82,7 +82,7 @@ export constexpr auto size_from_int(int x) -> std::optional<std::size_t>
   return static_cast<std::size_t>(x);
 }
 
-export constexpr auto int_from_size(std::size_t x) -> std::optional<int>
+constexpr auto int_from_size(std::size_t x) -> std::optional<int>
 {
   constexpr auto int_max = size_from_int(std::numeric_limits<int>::max());
   static_assert(int_max.has_value());
@@ -91,7 +91,7 @@ export constexpr auto int_from_size(std::size_t x) -> std::optional<int>
   return static_cast<int>(x);
 }
 
-export class zstring_view
+class zstring_view
 {
   char const* s_;
   std::size_t length_;
@@ -107,13 +107,16 @@ public:
   {
   }
 
-  auto length() const -> std::size_t { return length_; }
+  constexpr auto length() const -> std::size_t { return length_; }
 
-  auto c_str() const -> char const* { return s_; }
+  constexpr auto c_str() const -> char const* { return s_; }
 
-  operator std::string_view() const { return std::string_view{s_, length_}; }
+  constexpr operator std::string_view() const
+  {
+    return std::string_view{s_, length_};
+  }
 
-  operator char const*() const { return s_; }
+  constexpr operator char const*() const { return s_; }
 };
 
 // View for null-terminated strings for which we might not
@@ -123,7 +126,7 @@ public:
 //
 // It is undefined behavior to assign to a lazy_zstring_view when
 // it is in use by other threads.
-export class lazy_zstring_view
+class lazy_zstring_view
 {
   static constexpr auto unset_length = std::numeric_limits<std::size_t>::max();
 
@@ -136,70 +139,21 @@ public:
     : s_{s}, length_{s ? unset_length : 0}
   {
   }
+  lazy_zstring_view(lazy_zstring_view const& sv) noexcept;
+  lazy_zstring_view(lazy_zstring_view&& sv) noexcept;
 
   ~lazy_zstring_view() = default;
 
-  lazy_zstring_view(lazy_zstring_view const& sv) noexcept
-    : s_{sv.s_}, length_{sv.length_.load(std::memory_order_acquire)}
-  {
-  }
-
-  lazy_zstring_view(lazy_zstring_view&& sv) noexcept
-    : s_{sv.s_}, length_{sv.length_.load(std::memory_order_acquire)}
-  {
-  }
-
-  auto operator=(lazy_zstring_view const& rhs) noexcept -> lazy_zstring_view&
-  {
-    if (this != &rhs)
-    {
-      s_ = rhs.s_;
-      length_.store(
-          rhs.length_.load(std::memory_order_acquire),
-          std::memory_order_release);
-    }
-    return *this;
-  }
-
-  auto operator=(lazy_zstring_view&& rhs) noexcept -> lazy_zstring_view&
-  {
-    return *this = rhs; // use the copy assignment operator
-  }
-
-  auto length() const noexcept -> std::size_t
-  {
-    if (auto v = length_.load(std::memory_order_acquire); v != unset_length)
-      return v;
-    auto l = std::char_traits<char>::length(s_);
-    length_.store(l, std::memory_order_release);
-    return l;
-  }
-
-  auto c_str() const noexcept -> char const* { return s_; }
+  auto operator=(lazy_zstring_view const& rhs) noexcept -> lazy_zstring_view&;
+  auto operator=(lazy_zstring_view&& rhs) noexcept -> lazy_zstring_view&;
 
-  operator std::string_view() const noexcept
-  {
-    return std::string_view{s_, length()};
-  }
+  auto length() const noexcept -> std::size_t;
+  auto c_str() const noexcept -> char const*;
 
-  operator char const*() const noexcept { return s_; }
+  operator std::string_view() const noexcept;
+  operator char const*() const noexcept;
 
-  auto operator==(std::string_view sv) const noexcept -> bool
-  {
-    if (auto v = length_.load(std::memory_order_acquire); v != unset_length)
-      if (sv.length() != v)
-        return false;
-    auto res = std::char_traits<char>::compare(s_, sv.data(), sv.length());
-    if (res != 0)
-      return false;
-    // Strings are equal for sv.length() characters.
-    if (s_[sv.length()] != '\0')
-      return false;
-    // Strings are actually equal, and we have just found out the
-    // length of this string, so we might as well set it.
-    length_.store(sv.length(), std::memory_order_release);
-    return true;
-  }
+  auto operator==(std::string_view sv) const noexcept -> bool;
 };
 
 constexpr auto operator""_zsv(char const* s, std::size_t length) noexcept
@@ -208,12 +162,9 @@ constexpr auto operator""_zsv(char const* s, std::size_t length) noexcept
   return zstring_view{s, length};
 }
 
-auto operator==(zstring_view lhs, zstring_view rhs) -> bool
-{
-  return std::string_view{lhs} == std::string_view{rhs};
-}
+auto operator==(zstring_view lhs, zstring_view rhs) -> bool;
 
-export constexpr auto split_on(std::string_view s, char c)
+constexpr auto split_on(std::string_view s, char c)
     -> std::pair<std::string_view, std::optional<std::string_view>>
 {
   if (auto i = s.find(c); i != std::string_view::npos)
@@ -221,10 +172,10 @@ export constexpr auto split_on(std::string_view s, char c)
   return std::make_pair(s, std::nullopt);
 }
 
-export template <class T>
+template <class T>
 class not_null;
 
-export template <class T>
+template <class T>
 class not_null<T*>
 {
   T* p_;
@@ -264,10 +215,10 @@ public:
 
   auto operator->() const noexcept -> T* { return p_; }
 };
-export template <class T>
+template <class T>
 explicit not_null(T*) -> not_null<T*>;
 
-export template <>
+template <>
 class not_null<lazy_zstring_view>
 {
   lazy_zstring_view s_;
@@ -285,6 +236,6 @@ public:
   operator std::string_view() const noexcept { return s_; }
   operator char const*() const noexcept { return s_; }
 };
-export explicit not_null(lazy_zstring_view s) -> not_null<lazy_zstring_view>;
+explicit not_null(lazy_zstring_view s) -> not_null<lazy_zstring_view>;
 
 } // namespace routemon::util
diff --git a/server/src/xml.cppm b/server/src/xml.cppm
index 4648047..ffaf159 100644
--- a/server/src/xml.cppm
+++ b/server/src/xml.cppm
@@ -201,7 +201,8 @@ struct eof_event
 
 using event = std::variant<
     start_element_event, end_element_event, character_data_event,
-    processing_instructions_event, xml_decl_event, eof_event>;
+    processing_instructions_event, xml_decl_event, eof_event
+>;
 
 template <class T>
 concept event_type = requires(event ev) { std::get<T>(ev); };
@@ -522,6 +523,7 @@ public:
       }
       constexpr auto await_resume() const noexcept -> void { return; }
     };
+
     if (this->continuation())
     {
       return awaiter{this->continuation()};
@@ -548,16 +550,19 @@ public:
       {
         return !executor_->advance_flag();
       }
+
       auto await_suspend(std::coroutine_handle<promise<T>> h) -> void
       {
         executor_->set_continuation(h.promise().base_handle());
       }
+
       [[nodiscard]] auto await_resume() const -> event
       {
         assert(executor_->event());
         return executor_->event().value();
       }
     };
+
     return awaiter{req.executor};
   }
 
@@ -572,6 +577,7 @@ public:
       {
         return false;
       }
+
       auto await_suspend(std::coroutine_handle<promise<T>> h)
           -> std::coroutine_handle<>
       {
@@ -580,6 +586,7 @@ public:
         next_->set_continuation(h.promise().base_handle());
         return next_->handle();
       }
+
       auto await_resume() -> U
       {
         // Promise is still valid since coroutine frame is still alive
@@ -599,6 +606,7 @@ public:
         }
       }
     };
+
     return awaiter{util::not_null{&coro.promise()}};
   }
 };
@@ -717,14 +725,16 @@ auto expect_element(
   co_await expect_end_element(e, want);
   co_await ignore_whitespace(e);
   co_return std::forward<
-      parser_invoke_result_t<decltype(p), executor_ref, attribute_view>>(res);
+      parser_invoke_result_t<decltype(p), executor_ref, attribute_view>
+  >(res);
 }
 
 auto allow_element(
     executor_ref e, qname_view want,
     parser_invocable<executor_ref, attribute_view> auto p)
     -> parser<std::optional<
-        parser_invoke_result_t<decltype(p), executor_ref, attribute_view>>>
+        parser_invoke_result_t<decltype(p), executor_ref, attribute_view>
+    >>
 {
   co_await ignore_whitespace(e);
   if (auto mattrs = co_await allow_start_element(e, want))
@@ -734,8 +744,8 @@ auto allow_element(
     co_await ignore_whitespace(e);
     co_return std::make_optional(
         std::forward<
-            parser_invoke_result_t<decltype(p), executor_ref, attribute_view>>(
-            res));
+            parser_invoke_result_t<decltype(p), executor_ref, attribute_view>
+        >(res));
   }
   co_return std::nullopt;
 }
@@ -744,7 +754,8 @@ auto allow_element(
     executor_ref e, qname_view want,
     parser_invocable<executor_ref, attribute_view> auto p) -> parser<bool>
   requires std::is_void_v<
-      parser_invoke_result_t<decltype(p), executor_ref, attribute_view>>
+      parser_invoke_result_t<decltype(p), executor_ref, attribute_view>
+  >
 {
   co_await ignore_whitespace(e);
   if (auto mattrs = co_await allow_start_element(e, want))