[router] add reasoning and tool parser argument in router (#11290)

sgl-router/py_src/sglang_router/router_args.py

@@ -86,6 +86,9 @@ class RouterArgs:
     # Tokenizer configuration
     model_path: Optional[str] = None
     tokenizer_path: Optional[str] = None
+    # Parser configuration
+    reasoning_parser: Optional[str] = None
+    tool_call_parser: Optional[str] = None
 
     @staticmethod
     def add_cli_args(
@@ -446,6 +449,18 @@ class RouterArgs:
             default=None,
             help="Explicit tokenizer path (overrides model_path tokenizer if provided)",
         )
+        parser.add_argument(
+            f"--{prefix}reasoning-parser",
+            type=str,
+            default=None,
+            help="Specify the parser for reasoning models (e.g., deepseek-r1, qwen3)",
+        )
+        parser.add_argument(
+            f"--{prefix}tool-call-parser",
+            type=str,
+            default=None,
+            help="Specify the parser for handling tool-call interactions",
+        )
 
     @classmethod
     def from_cli_args(

sgl-router/src/config/types.rs

@@ -73,6 +73,10 @@ pub struct RouterConfig {
     /// Oracle history backend configuration (required when `history_backend` = "oracle")
     #[serde(skip_serializing_if = "Option::is_none")]
     pub oracle: Option<OracleConfig>,
+    /// Parser for reasoning models (e.g., deepseek-r1, qwen3)
+    pub reasoning_parser: Option<String>,
+    /// Parser for handling tool-call interactions
+    pub tool_call_parser: Option<String>,
 }
 
 fn default_history_backend() -> HistoryBackend {
@@ -448,6 +452,8 @@ impl Default for RouterConfig {
             tokenizer_path: None,
             history_backend: default_history_backend(),
             oracle: None,
+            reasoning_parser: None,
+            tool_call_parser: None,
         }
     }
 }
@@ -990,6 +996,8 @@ mod tests {
             tokenizer_path: None,
             history_backend: default_history_backend(),
             oracle: None,
+            reasoning_parser: None,
+            tool_call_parser: None,
         };
 
         assert!(config.mode.is_pd_mode());
@@ -1055,6 +1063,8 @@ mod tests {
             tokenizer_path: None,
             history_backend: default_history_backend(),
             oracle: None,
+            reasoning_parser: None,
+            tool_call_parser: None,
         };
 
         assert!(!config.mode.is_pd_mode());
@@ -1116,6 +1126,8 @@ mod tests {
             tokenizer_path: None,
             history_backend: default_history_backend(),
             oracle: None,
+            reasoning_parser: None,
+            tool_call_parser: None,
         };
 
         assert!(config.has_service_discovery());

sgl-router/src/lib.rs

@@ -90,6 +90,8 @@ struct Router {
     connection_mode: config::ConnectionMode,
     model_path: Option<String>,
     tokenizer_path: Option<String>,
+    reasoning_parser: Option<String>,
+    tool_call_parser: Option<String>,
 }
 
 impl Router {
@@ -216,6 +218,8 @@ impl Router {
             tokenizer_path: self.tokenizer_path.clone(),
             history_backend: config::HistoryBackend::Memory,
             oracle: None,
+            reasoning_parser: self.reasoning_parser.clone(),
+            tool_call_parser: self.tool_call_parser.clone(),
         })
     }
 }
@@ -280,6 +284,8 @@ impl Router {
         rate_limit_tokens_per_second = None,
         model_path = None,
         tokenizer_path = None,
+        reasoning_parser = None,
+        tool_call_parser = None,
     ))]
     #[allow(clippy::too_many_arguments)]
     fn new(
@@ -339,6 +345,8 @@ impl Router {
         rate_limit_tokens_per_second: Option<usize>,
         model_path: Option<String>,
         tokenizer_path: Option<String>,
+        reasoning_parser: Option<String>,
+        tool_call_parser: Option<String>,
     ) -> PyResult<Self> {
         let mut all_urls = worker_urls.clone();
 
@@ -412,6 +420,8 @@ impl Router {
             connection_mode,
             model_path,
             tokenizer_path,
+            reasoning_parser,
+            tool_call_parser,
         })
     }
 

sgl-router/src/main.rs

@@ -281,6 +281,12 @@ struct CliArgs {
 
     #[arg(long, env = "ATP_POOL_TIMEOUT_SECS")]
     oracle_pool_timeout_secs: Option<u64>,
+
+    #[arg(long)]
+    reasoning_parser: Option<String>,
+
+    #[arg(long)]
+    tool_call_parser: Option<String>,
 }
 
 enum OracleConnectSource {
@@ -557,6 +563,8 @@ impl CliArgs {
             tokenizer_path: self.tokenizer_path.clone(),
             history_backend,
             oracle,
+            reasoning_parser: self.reasoning_parser.clone(),
+            tool_call_parser: self.tool_call_parser.clone(),
         })
     }
 

sgl-router/src/routers/grpc/pd_router.rs

@@ -53,6 +53,8 @@ pub struct GrpcPDRouter {
     dp_aware: bool,
     api_key: Option<String>,
     retry_config: RetryConfig,
+    configured_reasoning_parser: Option<String>,
+    configured_tool_parser: Option<String>,
 }
 
 impl GrpcPDRouter {
@@ -88,6 +90,8 @@ impl GrpcPDRouter {
             dp_aware: ctx.router_config.dp_aware,
             api_key: ctx.router_config.api_key.clone(),
             retry_config: ctx.router_config.effective_retry_config(),
+            configured_reasoning_parser: ctx.configured_reasoning_parser.clone(),
+            configured_tool_parser: ctx.configured_tool_parser.clone(),
         })
     }
 
@@ -1179,9 +1183,13 @@ impl GrpcPDRouter {
         created: u64,
     ) -> (String, Option<ChatCompletionStreamResponse>, bool) {
         // Get or create parser for this index
-        reasoning_parsers
+        reasoning_parsers.entry(index).or_insert_with(|| {
-            .entry(index)
+            utils::get_reasoning_parser(
-            .or_insert_with(|| self.reasoning_parser_factory.get_pooled(model));
+                &self.reasoning_parser_factory,
+                self.configured_reasoning_parser.as_ref(),
+                model,
+            )
+        });
 
         if let Some(pooled_parser) = reasoning_parsers.get(&index) {
             let (parse_result, in_reasoning) = {
@@ -1248,9 +1256,13 @@ impl GrpcPDRouter {
         let mut chunks = Vec::new();
 
         // Get or create parser for this index
-        tool_parsers
+        tool_parsers.entry(index).or_insert_with(|| {
-            .entry(index)
+            utils::get_tool_parser(
-            .or_insert_with(|| self.tool_parser_factory.get_pooled(model));
+                &self.tool_parser_factory,
+                self.configured_tool_parser.as_ref(),
+                model,
+            )
+        });
 
         if let Some(pooled_parser) = tool_parsers.get(&index) {
             let mut parser = pooled_parser.lock().await;
@@ -1737,9 +1749,11 @@ impl GrpcPDRouter {
 
         // Check if reasoning parsing is enabled and separate_reasoning is requested
         if original_request.separate_reasoning {
-            let pooled_parser = self
+            let pooled_parser = utils::get_reasoning_parser(
-                .reasoning_parser_factory
+                &self.reasoning_parser_factory,
-                .get_pooled(&original_request.model);
+                self.configured_reasoning_parser.as_ref(),
+                &original_request.model,
+            );
 
             let mut parser = pooled_parser
                 .lock()
@@ -1860,7 +1874,11 @@ impl GrpcPDRouter {
         history_tool_calls_count: usize,
     ) -> (Option<Vec<ToolCall>>, String) {
         // Get pooled parser for this model
-        let pooled_parser = self.tool_parser_factory.get_pooled(model);
+        let pooled_parser = utils::get_tool_parser(
+            &self.tool_parser_factory,
+            self.configured_tool_parser.as_ref(),
+            model,
+        );
 
         // Check format detection first
         let can_parse = {

sgl-router/src/routers/grpc/router.rs

@@ -53,6 +53,8 @@ pub struct GrpcRouter {
     dp_aware: bool,
     api_key: Option<String>,
     retry_config: RetryConfig,
+    configured_reasoning_parser: Option<String>,
+    configured_tool_parser: Option<String>,
 }
 
 impl GrpcRouter {
@@ -87,6 +89,8 @@ impl GrpcRouter {
             dp_aware: ctx.router_config.dp_aware,
             api_key: ctx.router_config.api_key.clone(),
             retry_config: ctx.router_config.effective_retry_config(),
+            configured_reasoning_parser: ctx.configured_reasoning_parser.clone(),
+            configured_tool_parser: ctx.configured_tool_parser.clone(),
         })
     }
 
@@ -301,7 +305,11 @@ impl GrpcRouter {
         history_tool_calls_count: usize,
     ) -> (Option<Vec<ToolCall>>, String) {
         // Get pooled parser for this model
-        let pooled_parser = self.tool_parser_factory.get_pooled(model);
+        let pooled_parser = utils::get_tool_parser(
+            &self.tool_parser_factory,
+            self.configured_tool_parser.as_ref(),
+            model,
+        );
 
         // Check format detection first
         let can_parse = {
@@ -496,9 +504,13 @@ impl GrpcRouter {
         created: u64,
     ) -> (String, Option<ChatCompletionStreamResponse>, bool) {
         // Get or create parser for this index
-        reasoning_parsers
+        reasoning_parsers.entry(index).or_insert_with(|| {
-            .entry(index)
+            utils::get_reasoning_parser(
-            .or_insert_with(|| self.reasoning_parser_factory.get_pooled(model));
+                &self.reasoning_parser_factory,
+                self.configured_reasoning_parser.as_ref(),
+                model,
+            )
+        });
 
         if let Some(pooled_parser) = reasoning_parsers.get(&index) {
             let (parse_result, in_reasoning) = {
@@ -569,9 +581,13 @@ impl GrpcRouter {
         let mut chunks = Vec::new();
 
         // Get or create parser for this index
-        tool_parsers
+        tool_parsers.entry(index).or_insert_with(|| {
-            .entry(index)
+            utils::get_tool_parser(
-            .or_insert_with(|| self.tool_parser_factory.get_pooled(model));
+                &self.tool_parser_factory,
+                self.configured_tool_parser.as_ref(),
+                model,
+            )
+        });
 
         if let Some(pooled_parser) = tool_parsers.get(&index) {
             let mut parser = pooled_parser.lock().await;
@@ -1615,9 +1631,11 @@ impl GrpcRouter {
 
         // Check if reasoning parsing is enabled and separate_reasoning is requested
         if original_request.separate_reasoning {
-            let pooled_parser = self
+            let pooled_parser = utils::get_reasoning_parser(
-                .reasoning_parser_factory
+                &self.reasoning_parser_factory,
-                .get_pooled(&original_request.model);
+                self.configured_reasoning_parser.as_ref(),
+                &original_request.model,
+            );
 
             let mut parser = pooled_parser
                 .lock()

sgl-router/src/routers/grpc/utils.rs

@@ -641,6 +641,64 @@ pub fn generate_tool_call_id(
     }
 }
 
+/// Get the appropriate reasoning parser for a model
+///
+/// If a parser name is explicitly configured, use that parser.
+/// Otherwise, auto-detect based on the model name.
+pub fn get_reasoning_parser(
+    reasoning_parser_factory: &crate::reasoning_parser::ReasoningParserFactory,
+    configured_parser: Option<&String>,
+    model: &str,
+) -> crate::reasoning_parser::PooledParser {
+    use tracing::warn;
+
+    if let Some(parser_name) = configured_parser {
+        // Use configured parser if specified
+        reasoning_parser_factory
+            .registry()
+            .get_pooled_parser(parser_name)
+            .unwrap_or_else(|| {
+                warn!(
+                    "Configured reasoning parser '{}' not found, falling back to model-based selection",
+                    parser_name
+                );
+                reasoning_parser_factory.get_pooled(model)
+            })
+    } else {
+        // Auto-detect based on model
+        reasoning_parser_factory.get_pooled(model)
+    }
+}
+
+/// Get the appropriate tool parser for a model
+///
+/// If a parser name is explicitly configured, use that parser.
+/// Otherwise, auto-detect based on the model name.
+pub fn get_tool_parser(
+    tool_parser_factory: &crate::tool_parser::ToolParserFactory,
+    configured_parser: Option<&String>,
+    model: &str,
+) -> crate::tool_parser::PooledToolParser {
+    use tracing::warn;
+
+    if let Some(parser_name) = configured_parser {
+        // Use configured parser if specified
+        tool_parser_factory
+            .registry()
+            .get_pooled_parser(parser_name)
+            .unwrap_or_else(|| {
+                warn!(
+                    "Configured tool parser '{}' not found, falling back to model-based selection",
+                    parser_name
+                );
+                tool_parser_factory.get_pooled(model)
+            })
+    } else {
+        // Auto-detect based on model
+        tool_parser_factory.get_pooled(model)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

sgl-router/src/server.rs

@@ -52,6 +52,8 @@ pub struct AppContext {
     pub router_manager: Option<Arc<RouterManager>>,
     pub response_storage: SharedResponseStorage,
     pub load_monitor: Option<Arc<LoadMonitor>>,
+    pub configured_reasoning_parser: Option<String>,
+    pub configured_tool_parser: Option<String>,
 }
 
 impl AppContext {
@@ -115,6 +117,9 @@ impl AppContext {
             router_config.worker_startup_check_interval_secs,
         )));
 
+        let configured_reasoning_parser = router_config.reasoning_parser.clone();
+        let configured_tool_parser = router_config.tool_call_parser.clone();
+
         Ok(Self {
             client,
             router_config,
@@ -127,6 +132,8 @@ impl AppContext {
             router_manager,
             response_storage,
             load_monitor,
+            configured_reasoning_parser,
+            configured_tool_parser,
         })
     }
 }

sgl-router/src/service_discovery.rs

@@ -543,6 +543,8 @@ mod tests {
             router_manager: None,
             response_storage: Arc::new(crate::data_connector::MemoryResponseStorage::new()),
             load_monitor: None,
+            configured_reasoning_parser: None,
+            configured_tool_parser: None,
         })
     }
 

sgl-router/tests/api_endpoints_test.rs

@@ -63,6 +63,8 @@ impl TestContext {
             tokenizer_path: None,
             history_backend: sglang_router_rs::config::HistoryBackend::Memory,
             oracle: None,
+            reasoning_parser: None,
+            tool_call_parser: None,
         };
 
         Self::new_with_config(config, worker_configs).await
@@ -1396,6 +1398,8 @@ mod error_tests {
             tokenizer_path: None,
             history_backend: sglang_router_rs::config::HistoryBackend::Memory,
             oracle: None,
+            reasoning_parser: None,
+            tool_call_parser: None,
         };
 
         let ctx = TestContext::new_with_config(
@@ -1755,6 +1759,8 @@ mod pd_mode_tests {
             tokenizer_path: None,
             history_backend: sglang_router_rs::config::HistoryBackend::Memory,
             oracle: None,
+            reasoning_parser: None,
+            tool_call_parser: None,
         };
 
         // Create app context
@@ -1915,6 +1921,8 @@ mod request_id_tests {
             tokenizer_path: None,
             history_backend: sglang_router_rs::config::HistoryBackend::Memory,
             oracle: None,
+            reasoning_parser: None,
+            tool_call_parser: None,
         };
 
         let ctx = TestContext::new_with_config(

sgl-router/tests/responses_api_test.rs

@@ -76,6 +76,8 @@ async fn test_non_streaming_mcp_minimal_e2e_with_persistence() {
         tokenizer_path: None,
         history_backend: sglang_router_rs::config::HistoryBackend::Memory,
         oracle: None,
+        reasoning_parser: None,
+        tool_call_parser: None,
     };
 
     // Create router and context
@@ -508,6 +510,8 @@ async fn test_multi_turn_loop_with_mcp() {
         tokenizer_path: None,
         history_backend: sglang_router_rs::config::HistoryBackend::Memory,
         oracle: None,
+        reasoning_parser: None,
+        tool_call_parser: None,
     };
 
     let ctx = AppContext::new(router_cfg, reqwest::Client::new(), 64, None).expect("ctx");
@@ -686,6 +690,8 @@ async fn test_max_tool_calls_limit() {
         tokenizer_path: None,
         history_backend: sglang_router_rs::config::HistoryBackend::Memory,
         oracle: None,
+        reasoning_parser: None,
+        tool_call_parser: None,
     };
 
     let ctx = AppContext::new(router_cfg, reqwest::Client::new(), 64, None).expect("ctx");
@@ -826,6 +832,8 @@ async fn setup_streaming_mcp_test() -> (
         tokenizer_path: None,
         history_backend: sglang_router_rs::config::HistoryBackend::Memory,
         oracle: None,
+        reasoning_parser: None,
+        tool_call_parser: None,
     };
 
     let ctx = AppContext::new(router_cfg, reqwest::Client::new(), 64, None).expect("ctx");

sgl-router/tests/test_openai_routing.rs

@@ -826,6 +826,8 @@ fn oracle_config_validation_requires_config_when_enabled() {
         },
         history_backend: HistoryBackend::Oracle,
         oracle: None,
+        reasoning_parser: None,
+        tool_call_parser: None,
         ..Default::default()
     };
 

sgl-router/tests/test_pd_routing.rs

@@ -195,6 +195,8 @@ mod test_pd_routing {
                 tokenizer_path: None,
                 history_backend: sglang_router_rs::config::HistoryBackend::Memory,
                 oracle: None,
+                reasoning_parser: None,
+                tool_call_parser: None,
             };
 
             let app_context =