Implement HTTP handlers / webhooks in Rust modules

crates/bindings-cpp/CMakeLists.txt

@@ -30,6 +30,7 @@ target_sources(spacetimedb_cpp_library PRIVATE ${LIBRARY_SOURCES})
 
 # Require C++20 for consumers of this library without forcing global flags
 target_compile_features(spacetimedb_cpp_library PUBLIC cxx_std_20)
+target_compile_definitions(spacetimedb_cpp_library PRIVATE SPACETIMEDB_UNSTABLE_FEATURES)
 
 # Set include directories
 target_include_directories(spacetimedb_cpp_library
@@ -60,46 +61,5 @@ if(PROJECT_IS_TOP_LEVEL)
     set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 endif()
 
-# ---- Tests ----
-# Default: ON only when building this project directly; OFF when used via FetchContent/add_subdirectory
-if(CMAKE_VERSION VERSION_LESS 3.21)
-    # Fallback heuristic for older CMake
-    set(_is_top_level FALSE)
-    if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
-        set(_is_top_level TRUE)
-    endif()
-else()
-    set(_is_top_level ${PROJECT_IS_TOP_LEVEL})
-endif()
-
-option(BUILD_TESTS "Build the test suite" ${_is_top_level})
-
-if(BUILD_TESTS AND NOT CMAKE_SYSTEM_NAME STREQUAL "Emscripten")
-    enable_testing()
-
-    # Add test executable
-    add_executable(test_bsatn tests/main.cpp tests/module_library_unit_tests.cpp)
-
-    # Link against the module library
-    target_link_libraries(test_bsatn PRIVATE spacetimedb_cpp_library)
-
-    # Set C++20 standard for tests
-    target_compile_features(test_bsatn PRIVATE cxx_std_20)
-
-    # Add test to CTest
-    add_test(NAME bsatn_tests COMMAND test_bsatn)
-
-    # Add verbose test variant
-    add_test(NAME bsatn_tests_verbose COMMAND test_bsatn -v)
-
-    # Set test properties
-    set_tests_properties(bsatn_tests PROPERTIES 
-        TIMEOUT 30
-        LABELS "unit"
-    )
-
-    set_tests_properties(bsatn_tests_verbose PROPERTIES 
-        TIMEOUT 30
-        LABELS "unit;verbose"
-    )
-endif()
+# Unit/compile/smoke test harnesses live under `tests/` as standalone runners
+# rather than being built through the top-level library CMake target.

crates/bindings-cpp/include/spacetimedb.h

@@ -126,6 +126,11 @@
 
 // Procedure context and macros
 #include "spacetimedb/procedure_macros.h"
+#ifdef SPACETIMEDB_UNSTABLE_FEATURES
+#include "spacetimedb/handler_context.h"
+#include "spacetimedb/router.h"
+#include "spacetimedb/http_handler_macros.h"
+#endif
 
 // =============================================================================
 // VIEW SYSTEM

crates/bindings-cpp/include/spacetimedb/abi/abi.h

@@ -216,6 +216,37 @@ int16_t __call_reducer__(
     BytesSource args,
     BytesSink error);
 
+STDB_EXPORT(__call_view__)
+int16_t __call_view__(
+    uint32_t id,
+    uint64_t sender_0, uint64_t sender_1, uint64_t sender_2, uint64_t sender_3,
+    BytesSource args,
+    BytesSink result);
+
+STDB_EXPORT(__call_view_anon__)
+int16_t __call_view_anon__(
+    uint32_t id,
+    BytesSource args,
+    BytesSink result);
+
+STDB_EXPORT(__call_procedure__)
+int16_t __call_procedure__(
+    uint32_t id,
+    uint64_t sender_0, uint64_t sender_1, uint64_t sender_2, uint64_t sender_3,
+    uint64_t conn_id_0, uint64_t conn_id_1,
+    uint64_t timestamp_microseconds,
+    BytesSource args_source,
+    BytesSink result_sink);
+
+STDB_EXPORT(__call_http_handler__)
+int16_t __call_http_handler__(
+    uint32_t id,
+    uint64_t timestamp_microseconds,
+    BytesSource request_source,
+    BytesSource request_body_source,
+    BytesSink response_sink,
+    BytesSink response_body_sink);
+
 // ========================================================================
 // WASI SHIMS
 // ========================================================================

crates/bindings-cpp/include/spacetimedb/handler_context.h

@@ -0,0 +1,92 @@
+#ifndef SPACETIMEDB_HANDLER_CONTEXT_H
+#define SPACETIMEDB_HANDLER_CONTEXT_H
+
+#ifndef SPACETIMEDB_UNSTABLE_FEATURES
+#error "spacetimedb/handler_context.h requires SPACETIMEDB_UNSTABLE_FEATURES to be enabled"
+#endif
+
+#include <spacetimedb/abi/FFI.h>
+#include <spacetimedb/bsatn/timestamp.h>
+#include <spacetimedb/bsatn/uuid.h>
+#include <spacetimedb/http.h>
+#include <spacetimedb/internal/tx_execution.h>
+#include <spacetimedb/random.h>
+#include <spacetimedb/tx_context.h>
+#include <array>
+#include <cstdint>
+#include <functional>
+#include <memory>
+#include <optional>
+#include <type_traits>
+
+namespace SpacetimeDB {
+
+struct HandlerContext {
+    Timestamp timestamp;
+    HttpClient http;
+
+private:
+    mutable std::shared_ptr<StdbRng> rng_instance;
+    mutable uint32_t counter_uuid_ = 0;
+
+public:
+    HandlerContext() = default;
+    explicit HandlerContext(Timestamp t) : timestamp(t) {}
+
+    Identity identity() const {
+        std::array<uint8_t, 32> id_bytes;
+        ::identity(id_bytes.data());
+        return Identity(id_bytes);
+    }
+
+    StdbRng& rng() const {
+        if (!rng_instance) {
+            rng_instance = std::make_shared<StdbRng>(timestamp);
+        }
+        return *rng_instance;
+    }
+
+    Uuid new_uuid_v4() const {
+        std::array<uint8_t, 16> random_bytes;
+        rng().fill_bytes(random_bytes.data(), random_bytes.size());
+        return Uuid::from_random_bytes_v4(random_bytes);
+    }
+
+    Uuid new_uuid_v7() const {
+        std::array<uint8_t, 4> random_bytes;
+        rng().fill_bytes(random_bytes.data(), random_bytes.size());
+        return Uuid::from_counter_v7(counter_uuid_, timestamp, random_bytes);
+    }
+
+#ifdef SPACETIMEDB_UNSTABLE_FEATURES
+    template<typename Func>
+    auto with_tx(Func&& body) -> decltype(body(std::declval<TxContext&>())) {
+        auto make_reducer_ctx = [](Timestamp tx_timestamp) {
+            return ReducerContext(
+                Identity{},
+                std::nullopt,
+                tx_timestamp,
+                AuthCtx::internal()
+            );
+        };
+        return Internal::with_tx(make_reducer_ctx, body);
+    }
+
+    template<typename Func>
+    auto try_with_tx(Func&& body) -> decltype(body(std::declval<TxContext&>())) {
+        auto make_reducer_ctx = [](Timestamp tx_timestamp) {
+            return ReducerContext(
+                Identity{},
+                std::nullopt,
+                tx_timestamp,
+                AuthCtx::internal()
+            );
+        };
+        return Internal::try_with_tx(make_reducer_ctx, body);
+    }
+#endif
+};
+
+} // namespace SpacetimeDB
+
+#endif // SPACETIMEDB_HANDLER_CONTEXT_H

crates/bindings-cpp/include/spacetimedb/http.h

@@ -3,6 +3,10 @@
 
 #pragma once
 
+#ifndef SPACETIMEDB_UNSTABLE_FEATURES
+#error "spacetimedb/http.h requires SPACETIMEDB_UNSTABLE_FEATURES to be enabled"
+#endif
+
 #include <string>
 #include <vector>
 #include <optional>
@@ -312,8 +316,10 @@ class HttpClient {
 
 } // namespace SpacetimeDB
 
-// Include implementation after class definition to avoid circular dependencies
-#ifdef SPACETIMEDB_UNSTABLE_FEATURES
+// Include implementation dependencies after class definition to avoid circular dependencies
+#if defined(SPACETIMEDB_UNSTABLE_FEATURES) && !defined(SPACETIMEDB_HTTP_CONVERT_H)
+#include "spacetimedb/logger.h"
+#include "spacetimedb/http_convert.h"
 #include "spacetimedb/http_client_impl.h"
 #endif
 

crates/bindings-cpp/include/spacetimedb/http_client_impl.h

@@ -7,7 +7,7 @@
 #include "spacetimedb/http_convert.h"
 #include "spacetimedb/abi/abi.h"
 #include "spacetimedb/bsatn/bsatn.h"
-#include "spacetimedb/internal/Module.h"
+#include "spacetimedb/internal/runtime_registration.h"
 
 namespace SpacetimeDB {
 
@@ -23,9 +23,9 @@ inline Outcome<HttpResponse> HttpClient::SendImpl(const HttpRequest& request) {
     // Prepare body bytes
     const std::vector<uint8_t>& body_bytes = request.body.bytes;
 
-    // Call host function
-    // Note: For empty body, we need to pass a valid pointer, not null
-    const uint8_t* body_ptr = body_bytes.empty() ? reinterpret_cast<const uint8_t*>("") : body_bytes.data();
+    // The host ABI requires a non-null, in-bounds body pointer even when body_len == 0.
+    static const uint8_t empty_sentinel = 0;
+    const uint8_t* body_ptr = body_bytes.empty() ? &empty_sentinel : body_bytes.data();
 
     BytesSource out[2] = {BytesSource{0}, BytesSource{0}};
     Status status = procedure_http_request(
@@ -40,15 +40,11 @@ inline Outcome<HttpResponse> HttpClient::SendImpl(const HttpRequest& request) {
         if (status.inner == 21) {
             // Read error message from out[0]
             std::vector<uint8_t> error_bytes = Internal::ConsumeBytes(out[0]);
-
-            LOG_INFO("HTTP: Error bytes: " + std::to_string(error_bytes.size()));
-
+
             // Decode BSATN string
             bsatn::Reader reader(error_bytes.data(), error_bytes.size());
             std::string error_message = bsatn::deserialize<std::string>(reader);
 
-            LOG_INFO("HTTP: Error message: " + error_message);
-
             return Err<HttpResponse>(std::move(error_message));
         }
 
@@ -57,7 +53,6 @@ inline Outcome<HttpResponse> HttpClient::SendImpl(const HttpRequest& request) {
             return Err<HttpResponse>("HTTP requests are blocked inside transactions. Call HTTP before with_tx() or try_with_tx().");
         }
 
-        LOG_INFO("HTTP: Unknown error code: " + std::to_string(status.inner));
         return Err<HttpResponse>("HTTP request failed with status code: " + std::to_string(status.inner));
     }
 

crates/bindings-cpp/include/spacetimedb/http_convert.h

@@ -237,6 +237,12 @@ inline HttpRequest from_wire(const wire::HttpRequest& request) {
     return result;
 }
 
+inline HttpRequest from_wire(const wire::HttpRequest& request, std::vector<uint8_t> body) {
+    HttpRequest result = from_wire(request);
+    result.body.bytes = std::move(body);
+    return result;
+}
+
 // ==================== HttpResponse Conversions ====================
 
 /**
@@ -268,7 +274,16 @@ inline HttpResponse from_wire(const wire::HttpResponse& response) {
     return result;
 }
 
+inline std::pair<wire::HttpResponse, std::vector<uint8_t>> to_wire_split(const HttpResponse& response) {
+    return {to_wire(response), response.body.bytes};
+}
+
 } // namespace convert
 } // namespace SpacetimeDB
 
+#ifdef SPACETIMEDB_UNSTABLE_FEATURES
+#include "spacetimedb/logger.h"
+#include "spacetimedb/http_client_impl.h"
+#endif
+
 #endif // SPACETIMEDB_HTTP_CONVERT_H

crates/bindings-cpp/include/spacetimedb/http_handler_macros.h

@@ -0,0 +1,61 @@
+#pragma once
+
+#ifndef SPACETIMEDB_UNSTABLE_FEATURES
+#error "spacetimedb/http_handler_macros.h requires SPACETIMEDB_UNSTABLE_FEATURES to be enabled"
+#endif
+
+#include "spacetimedb/handler_context.h"
+#include "spacetimedb/http.h"
+#include "spacetimedb/internal/runtime_registration.h"
+#include "spacetimedb/internal/template_utils.h"
+#include "spacetimedb/internal/v10_builder.h"
+#include "spacetimedb/macros.h"
+#include "spacetimedb/router.h"
+
+namespace SpacetimeDB::Internal {
+
+template<typename Func>
+inline void RegisterHttpHandlerMacro(const char* handler_name, Func func) {
+    using traits = function_traits<Func>;
+    static_assert(traits::arity == 2, "HTTP handlers must take exactly two arguments");
+    using ContextType = typename traits::template arg_t<0>;
+    using RequestType = typename traits::template arg_t<1>;
+    using ReturnType = typename traits::result_type;
+    static_assert(std::is_same_v<ContextType, HandlerContext>, "First parameter of HTTP handler must be HandlerContext");
+    static_assert(std::is_same_v<RequestType, HttpRequest>, "Second parameter of HTTP handler must be HttpRequest");
+    static_assert(std::is_same_v<ReturnType, HttpResponse>, "HTTP handlers must return HttpResponse");
+
+    std::function<HttpResponse(HandlerContext&, HttpRequest)> handler =
+        [func](HandlerContext& ctx, HttpRequest request) -> HttpResponse {
+            return func(ctx, std::move(request));
+        };
+    RegisterHttpHandlerHandler(handler_name, func, std::move(handler));
+    getV10Builder().RegisterHttpHandlerDef(handler_name);
+}
+
+} // namespace SpacetimeDB::Internal
+
+#define SPACETIMEDB_HTTP_HANDLER(handler_name, ctx_param, request_param) \
+    SpacetimeDB::HttpResponse handler_name(ctx_param, request_param); \
+    __attribute__((export_name("__preinit__60_http_handler_" #handler_name))) \
+    extern "C" void CONCAT(_spacetimedb_preinit_register_http_handler_, handler_name)() { \
+        ::SpacetimeDB::Internal::RegisterHttpHandlerMacro(#handler_name, handler_name); \
+    } \
+    SpacetimeDB::HttpResponse handler_name(ctx_param, request_param)
+
+#define SPACETIMEDB_HTTP_HANDLER_NAMED(handler_name, canonical_name, ctx_param, request_param) \
+    SpacetimeDB::HttpResponse handler_name(ctx_param, request_param); \
+    __attribute__((export_name("__preinit__60_http_handler_" #handler_name))) \
+    extern "C" void CONCAT(_spacetimedb_preinit_register_http_handler_, handler_name)() { \
+        ::SpacetimeDB::Internal::RegisterHttpHandlerMacro(#handler_name, handler_name); \
+        SpacetimeDB::Module::RegisterExplicitFunctionName(#handler_name, canonical_name); \
+    } \
+    SpacetimeDB::HttpResponse handler_name(ctx_param, request_param)
+
+#define SPACETIMEDB_HTTP_ROUTER(router_name) \
+    SpacetimeDB::Router router_name(); \
+    __attribute__((export_name("__preinit__61_http_router_" #router_name))) \
+    extern "C" void CONCAT(_spacetimedb_preinit_register_http_router_, router_name)() { \
+        ::SpacetimeDB::Internal::getV10Builder().RegisterHttpRouter(router_name()); \
+    } \
+    SpacetimeDB::Router router_name()