Add TRITONSERVER_ServerOptionsSetLogCallback API

include/triton/core/tritonserver.h

@@ -2139,6 +2139,42 @@ TRITONSERVER_DECLSPEC struct TRITONSERVER_Error*
 TRITONSERVER_ServerOptionsSetLogVerbose(
     struct TRITONSERVER_ServerOptions* options, int level);
 
+/// Type for log callback function. When registered, this callback will be
+/// invoked for each log message, allowing custom log handling (e.g.,
+/// integration with external logging systems).
+///
+/// \param level The log level of the message.
+/// \param filename The source file where the log message originated.
+/// \param line The line number in the source file.
+/// \param msg The log message content.
+/// \param userp User-provided pointer passed to
+/// TRITONSERVER_ServerOptionsSetLogCallback.
+typedef void (*TRITONSERVER_LogCallbackFn_t)(
+    TRITONSERVER_LogLevel level, const char* filename, int line,
+    const char* msg, void* userp);
+
+/// Set a callback function to receive log messages. This allows applications
+/// to integrate Triton logging with their own logging infrastructure.
+///
+/// When a callback is set with 'replace_default_logger' as true, the callback
+/// completely replaces the default logging behavior (writing to
+/// stdout/stderr/file). When false, the callback is invoked in addition to
+/// the default logging.
+///
+/// \param options The server options object.
+/// \param callback_fn The callback function to invoke for each log message,
+/// or nullptr to disable callback logging.
+/// \param userp User-provided pointer that will be passed to the callback.
+/// \param replace_default_logger If true, the callback replaces the default
+/// logging behavior. If false, callback is called in addition to default
+/// logging.
+/// \return a TRITONSERVER_Error indicating success or failure.
+TRITONSERVER_DECLSPEC struct TRITONSERVER_Error*
+TRITONSERVER_ServerOptionsSetLogCallback(
+    struct TRITONSERVER_ServerOptions* options,
+    TRITONSERVER_LogCallbackFn_t callback_fn, void* userp,
+    bool replace_default_logger);
+
 /// Enable or disable metrics collection in a server options.
 ///
 /// \param options The server options object.

src/tritonserver.cc

@@ -1545,6 +1545,77 @@ TRITONSERVER_ServerOptionsSetLogVerbose(
   return nullptr;  // Success
 }
 
+#ifdef TRITON_ENABLE_LOGGING
+namespace {
+
+// Context for bridging C callback to internal Logger callback
+struct LogCallbackContext {
+  TRITONSERVER_LogCallbackFn_t user_callback;
+  void* userp;
+};
+
+// Global context (logging is global in Triton)
+static LogCallbackContext* g_log_callback_context = nullptr;
+
+// Internal callback wrapper that converts Logger::Level to TRITONSERVER_LogLevel
+void LogCallbackWrapper(
+    triton::common::Logger::Level level, const char* filename, int line,
+    const char* msg, void* userp)
+{
+  auto* ctx = static_cast<LogCallbackContext*>(userp);
+  if (ctx == nullptr || ctx->user_callback == nullptr) {
+    return;
+  }
+
+  // Convert internal log level to C API log level
+  TRITONSERVER_LogLevel api_level;
+  switch (level) {
+    case triton::common::Logger::Level::kERROR:
+      api_level = TRITONSERVER_LOG_ERROR;
+      break;
+    case triton::common::Logger::Level::kWARNING:
+      api_level = TRITONSERVER_LOG_WARN;
+      break;
+    case triton::common::Logger::Level::kINFO:
+    default:
+      api_level = TRITONSERVER_LOG_INFO;
+      break;
+  }
+
+  ctx->user_callback(api_level, filename, line, msg, ctx->userp);
+}
+
+}  // namespace
+#endif  // TRITON_ENABLE_LOGGING
+
+// Set a callback function to receive log messages.
+TRITONAPI_DECLSPEC TRITONSERVER_Error*
+TRITONSERVER_ServerOptionsSetLogCallback(
+    TRITONSERVER_ServerOptions* options, TRITONSERVER_LogCallbackFn_t callback_fn,
+    void* userp, bool replace_default_logger)
+{
+#ifdef TRITON_ENABLE_LOGGING
+  // Clean up existing context if any
+  if (g_log_callback_context != nullptr) {
+    delete g_log_callback_context;
+    g_log_callback_context = nullptr;
+  }
+
+  if (callback_fn != nullptr) {
+    // Create new context for the callback
+    g_log_callback_context = new LogCallbackContext{callback_fn, userp};
+    LOG_SET_CALLBACK(LogCallbackWrapper, g_log_callback_context, replace_default_logger);
+  } else {
+    // Disable callback logging
+    LOG_SET_CALLBACK(nullptr, nullptr, false);
+  }
+  return nullptr;  // Success
+#else
+  return TRITONSERVER_ErrorNew(
+      TRITONSERVER_ERROR_UNSUPPORTED, "logging not supported");
+#endif  // TRITON_ENABLE_LOGGING
+}
+
 TRITONAPI_DECLSPEC TRITONSERVER_Error*
 TRITONSERVER_ServerOptionsSetLogFormat(
     TRITONSERVER_ServerOptions* options, const TRITONSERVER_LogFormat format)

src/tritonserver_stub.cc

@@ -471,6 +471,10 @@ TRITONSERVER_ServerOptionsSetLogVerbose()
 {
 }
 TRITONAPI_DECLSPEC void
+TRITONSERVER_ServerOptionsSetLogCallback()
+{
+}
+TRITONAPI_DECLSPEC void
 TRITONSERVER_ServerOptionsSetLogFormat()
 {
 }