[model-gateway] Dynamically Populate Tool Call Parser Choices (#14807)

sgl-model-gateway/bindings/python/Cargo.toml

@@ -10,6 +10,7 @@ crate-type = ["cdylib"]
 [dependencies]
 pyo3 = { version = "0.27.1", features = ["extension-module", "abi3-py38"] }
 tokio = { version = "1.42.0", features = ["full"] }
+once_cell = "1.19"
 
 [dependencies.sgl-model-gateway]
 path = "../.."

sgl-model-gateway/bindings/python/sglang_router/router_args.py

@@ -4,6 +4,8 @@ import logging
 import os
 from typing import Dict, List, Optional
 
+from sglang_router.sglang_router_rs import get_available_tool_call_parsers
+
 logger = logging.getLogger(__name__)
 
 
@@ -520,11 +522,13 @@ class RouterArgs:
             default=None,
             help="Specify the parser for reasoning models (e.g., deepseek-r1, qwen3)",
         )
+        tool_call_parser_choices = get_available_tool_call_parsers()
         parser.add_argument(
             f"--{prefix}tool-call-parser",
             type=str,
             default=None,
-            help="Specify the parser for handling tool-call interactions",
+            choices=tool_call_parser_choices,
+            help=f"Specify the parser for tool-call interactions (e.g., json, qwen)",
         )
         # MCP server configuration
         parser.add_argument(

sgl-model-gateway/bindings/python/src/lib.rs

@@ -1,5 +1,6 @@
 use pyo3::prelude::*;
 use sgl_model_gateway::*;
+use once_cell::sync::OnceCell;
 use std::collections::HashMap;
 
 // Define the enums with PyO3 bindings
@@ -730,6 +731,18 @@ fn get_verbose_version_string() -> String {
     version::get_verbose_version_string()
 }
 
+/// Get the list of available tool call parsers from the Rust factory.
+#[pyfunction]
+fn get_available_tool_call_parsers() -> Vec<String> {
+    static PARSERS: OnceCell<Vec<String>> = OnceCell::new();
+    PARSERS
+        .get_or_init(|| {
+            let factory = tool_parser::ParserFactory::new();
+            factory.list_parsers()
+        })
+        .clone()
+}
+
 #[pymodule]
 fn sglang_router_rs(m: &Bound<'_, PyModule>) -> PyResult<()> {
     m.add_class::<PolicyType>()?;
@@ -740,5 +753,6 @@ fn sglang_router_rs(m: &Bound<'_, PyModule>) -> PyResult<()> {
     m.add_class::<Router>()?;
     m.add_function(wrap_pyfunction!(get_version_string, m)?)?;
     m.add_function(wrap_pyfunction!(get_verbose_version_string, m)?)?;
+    m.add_function(wrap_pyfunction!(get_available_tool_call_parsers, m)?)?;
     Ok(())
 }