diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..8dbf26d
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,17 @@
+name: Build
+run-name: ${{github.actor}} build
+on:
+  push:
+  pull_request:
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install dependencies
+        run: sudo apt-get update && sudo apt-get install -y build-essential cmake clang clang-tidy libexpat1-dev zlib1g-dev
+      - name: Configure
+        run: cmake -Bbuild -S. -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++
+      - name: Build
+        run: cmake --build build -- -j$(nproc)
+
diff --git a/.gitignore b/.gitignore
index ada7844..618fe20 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,8 @@
 # artifacts
 build
 install
+/.cache
 
 # ide
 .vscode
-*.user
\ No newline at end of file
+*.user
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 900e4de..54863b8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,6 +6,8 @@ set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
+this is an error
+
 # Toggle integration tests
 option(INPUTOSM_INTEGRATION_TESTS "Build integration tests" ON)
 option(WARNINGS_AS_ERRORS "Treat warnings as errors" ON)
diff --git a/src/inputosmlog.cpp b/src/inputosmlog.cpp
index 6378eea..ecaf337 100644
--- a/src/inputosmlog.cpp
+++ b/src/inputosmlog.cpp
@@ -3,6 +3,7 @@
 #include <cstdarg>
 #include <cstdio>
 #include <cstring>
+#include <cstdlib>
 
 constexpr const char* kError = "err";
 constexpr const char* kInfo = "inf";
diff --git a/src/inputosmpbf.cpp b/src/inputosmpbf.cpp
index a3126dd..94a4e22 100644
--- a/src/inputosmpbf.cpp
+++ b/src/inputosmpbf.cpp
@@ -56,7 +56,7 @@ struct field_t
 
 struct string_table_t
 {
-    std::vector<uint32_t> st_index;
+    std::vector<std::size_t> st_index;
     std::vector<uint8_t> st_buffer;
 
     void clear()
diff --git a/src/inputosmxml.cpp b/src/inputosmxml.cpp
index 4bcf546..241b8a0 100644
--- a/src/inputosmxml.cpp
+++ b/src/inputosmxml.cpp
@@ -15,6 +15,7 @@
 #include "inputosmlog.h"
 #include "timeutil.h"
 
+#include <cstddef>
 #include <cstdint>
 #include <cstdio>
 #include <cstdlib>
@@ -46,9 +47,13 @@ enum class current_tag_t
 };
 current_tag_t current_tag;
 std::vector<std::string> current_strings;
-std::vector<tag_t> current_tags;
+std::vector<std::pair<int, int>> current_tags;
 std::vector<int64_t> current_refs;
-std::vector<relation_member_t> current_members;
+struct ext_relation_member_t : relation_member_t
+{
+    int role_index = -1;
+};
+std::vector<ext_relation_member_t> current_members;
 
 static void xml_start_node(const char **attr)
 {
@@ -80,7 +85,14 @@ static void xml_end_node()
 {
     // node end
     current_tag = current_tag_t::none;
-    current_node.tags = {current_tags.data(), current_tags.size()};
+    // assemble tags
+    std::vector<tag_t> tags;
+    for (std::size_t i = 0; i < current_tags.size(); i++)
+    {
+        tags.emplace_back(
+            tag_t{current_strings[current_tags[i].first].c_str(), current_strings[current_tags[i].second].c_str()});
+    }
+    current_node.tags = {tags.data(), tags.size()};
     if (parser_enabled && node_handler) parser_enabled = node_handler({&current_node, 1});
     current_tags.clear();
     current_strings.clear();
@@ -104,7 +116,14 @@ static void xml_end_way()
 {
     // way end
     current_tag = current_tag_t::none;
-    current_way.tags = {current_tags.data(), current_tags.size()};
+    // assemble tags
+    std::vector<tag_t> tags;
+    for (std::size_t i = 0; i < current_tags.size(); i++)
+    {
+        tags.emplace_back(
+            tag_t{current_strings[current_tags[i].first].c_str(), current_strings[current_tags[i].second].c_str()});
+    }
+    current_way.tags = {tags.data(), tags.size()};
     current_way.node_refs = {current_refs.data(), current_refs.size()};
     if (parser_enabled && way_handler) parser_enabled = way_handler({&current_way, 1});
     current_tags.clear();
@@ -130,8 +149,22 @@ static void xml_end_relation()
 {
     // end relation
     current_tag = current_tag_t::none;
-    current_relation.tags = {current_tags.data(), current_tags.size()};
-    current_relation.members = {current_members.data(), current_members.size()};
+    // assemble tags
+    std::vector<tag_t> tags;
+    for (std::size_t i = 0; i < current_tags.size(); i++)
+    {
+        tags.emplace_back(
+            tag_t{current_strings[current_tags[i].first].c_str(), current_strings[current_tags[i].second].c_str()});
+    }
+    current_relation.tags = {tags.data(), tags.size()};
+    // assemble members
+    std::vector<relation_member_t> members;
+    for (const auto &m : current_members)
+    {
+        members.emplace_back(
+            relation_member_t{m.type, m.id, m.role_index >= 0 ? current_strings[m.role_index].c_str() : nullptr});
+    }
+    current_relation.members = {members.data(), members.size()};
     if (parser_enabled && relation_handler) parser_enabled = relation_handler({&current_relation, 1});
     current_tags.clear();
     current_strings.clear();
@@ -150,7 +183,7 @@ static void xml_start_xtag(const char **attr)
             if (strcmp(attr[i], "v") == 0) current_strings.emplace_back(attr[i + 1]);
         }
         for (auto i = istart; i < current_strings.size(); i += 2)
-            current_tags.emplace_back(tag_t{current_strings[i].c_str(), current_strings[i + 1].c_str()});
+            current_tags.emplace_back(std::pair<int, int>{i, i + 1});
     }
 }
 
@@ -171,27 +204,32 @@ static void xml_start_member(const char **attr)
     // member start
     if (current_tag == current_tag_t::relation)
     {
-        relation_member_t member;
+        ext_relation_member_t member;
         for (int i = 0; attr[i]; i += 2)
         {
             if (strcmp(attr[i], "ref") == 0) member.id = atoll(attr[i + 1]);
             if (strcmp(attr[i], "type") == 0)
             {
                 if (strcmp(attr[i + 1], "node") == 0) member.type = 0;
-                if (strcmp(attr[i + 1], "way") == 0) member.type = 2;
+                if (strcmp(attr[i + 1], "way") == 0) member.type = 1;
                 if (strcmp(attr[i + 1], "relation") == 0) member.type = 2;
             }
             if (strcmp(attr[i], "role") == 0)
             {
                 current_strings.emplace_back(attr[i + 1]);
-                member.role = current_strings.back().c_str();
+                member.role_index = current_strings.size() - 1;
             }
         }
+        if (member.role_index < 0)
+        {
+            current_strings.emplace_back();
+            member.role_index = current_strings.size() - 1;
+        }
         current_members.emplace_back(member);
     }
 }
 
-static void xml_start_tag(void */*data*/, const char *el, const char **attr)
+static void xml_start_tag(void * /*data*/, const char *el, const char **attr)
 {
     // XML tag start
     if (strcmp(el, "node") == 0) xml_start_node(attr);
@@ -207,7 +245,7 @@ static void xml_start_tag(void */*data*/, const char *el, const char **attr)
     if (strcmp(el, "delete") == 0) osc_mode = mode_t::destroy;
 }
 
-static void xml_end_tag(void */*data*/, const char *el)
+static void xml_end_tag(void * /*data*/, const char *el)
 {
     // XML tag end
     if (strcmp(el, "node") == 0) xml_end_node();
diff --git a/src/timeutil.cpp b/src/timeutil.cpp
index af44232..716e0ac 100644
--- a/src/timeutil.cpp
+++ b/src/timeutil.cpp
@@ -13,7 +13,8 @@
 
 #include "timeutil.h"
 #include <chrono>
-#include <inttypes.h>
+#include <ctime>
+#include <cinttypes>
 
 int64_t now_ms()
 {
@@ -29,16 +30,24 @@ int64_t now_us()
 
 time_t str_to_timestamp(const char* str)
 {
-    struct tm timeinfo;
-    strptime(str, "%FT%TZ", &timeinfo);
-    return mktime(&timeinfo);
+    struct tm timeinfo{};
+    if (strptime(str, "%FT%TZ", &timeinfo) == nullptr)
+    {
+        return 0;
+    }
+    return timegm(&timeinfo);
 }
+
 time_t str_to_timestamp_osmstate(const char* str)
 {
-    struct tm timeinfo;
-    strptime(str, "%FT%H\\:%M\\:%SZ", &timeinfo);
-    return mktime(&timeinfo);
+    struct tm timeinfo{};
+    if (strptime(str, "%FT%H\\:%M\\:%SZ", &timeinfo) == nullptr)
+    {
+        return 0;
+    }
+    return timegm(&timeinfo);
 }
+
 std::string timestamp_to_str(const time_t rawtime)
 {
     struct tm* dt;