[router] add kimi-k2 tool parser (#9702)

Co-authored-by: Chang Su <chang.s.su@oracle.com>
This commit is contained in:
Simo Lin
2025-08-27 11:04:55 -07:00
committed by GitHub
parent 6f6beca49d
commit 5c06dcb75a
5 changed files with 440 additions and 4 deletions

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@@ -25,5 +25,6 @@ pub use types::{FunctionCall, PartialToolCall, StreamResult, TokenConfig, ToolCa
// Re-export parsers for convenience
pub use parsers::{
DeepSeekParser, JsonParser, LlamaParser, MistralParser, PythonicParser, QwenParser, Step3Parser,
DeepSeekParser, JsonParser, KimiK2Parser, LlamaParser, MistralParser, PythonicParser,
QwenParser, Step3Parser,
};

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@@ -0,0 +1,270 @@
use async_trait::async_trait;
use regex::Regex;
use crate::tool_parser::{
errors::ToolParserResult,
partial_json::PartialJson,
state::ParseState,
traits::ToolParser,
types::{FunctionCall, StreamResult, ToolCall},
};
/// Kimi K2 format parser for tool calls
///
/// Handles the Kimi K2 specific format:
/// `<|tool_calls_section_begin|><|tool_call_begin|>functions.{name}:{index}<|tool_call_argument_begin|>{json_args}<|tool_call_end|><|tool_calls_section_end|>`
///
/// Features:
/// - Token-based delimiters
/// - Function calls with explicit indexing
/// - JSON arguments
pub struct KimiK2Parser {
/// Parser for handling incomplete JSON during streaming
partial_json: PartialJson,
/// Regex for extracting complete tool calls
tool_call_extractor: Regex,
/// Regex for extracting partial tool calls (streaming)
stream_tool_call_extractor: Regex,
}
impl KimiK2Parser {
/// Create a new Kimi K2 parser
pub fn new() -> Self {
// Pattern for complete tool calls
let tool_call_pattern = r"<\|tool_call_begin\|>\s*(?P<tool_call_id>[\w\.]+:\d+)\s*<\|tool_call_argument_begin\|>\s*(?P<function_arguments>\{.*?\})\s*<\|tool_call_end\|>";
let tool_call_extractor = Regex::new(tool_call_pattern).expect("Valid regex pattern");
// Pattern for streaming (partial) tool calls
let stream_pattern = r"<\|tool_call_begin\|>\s*(?P<tool_call_id>[\w\.]+:\d+)\s*<\|tool_call_argument_begin\|>\s*(?P<function_arguments>\{.*)";
let stream_tool_call_extractor = Regex::new(stream_pattern).expect("Valid regex pattern");
Self {
partial_json: PartialJson::default(),
tool_call_extractor,
stream_tool_call_extractor,
}
}
/// Check if text contains Kimi K2 tool markers
fn has_tool_markers(&self, text: &str) -> bool {
text.contains("<|tool_calls_section_begin|>")
}
/// Parse function ID to extract name and index
fn parse_function_id(&self, id: &str) -> Option<(String, usize)> {
// Format: functions.{name}:{index} or namespace.functions.{name}:{index}
// Extract everything after the last dot before the colon as the function name
if let Some(colon_pos) = id.rfind(':') {
let before_colon = &id[..colon_pos];
let index_str = &id[colon_pos + 1..];
// Find the last dot to extract the function name
if let Some(dot_pos) = before_colon.rfind('.') {
let func_name = &before_colon[dot_pos + 1..];
if let Ok(index) = index_str.parse::<usize>() {
return Some((func_name.to_string(), index));
}
}
}
None
}
}
impl Default for KimiK2Parser {
fn default() -> Self {
Self::new()
}
}
#[async_trait]
impl ToolParser for KimiK2Parser {
async fn parse_complete(&self, text: &str) -> ToolParserResult<Vec<ToolCall>> {
// Check if text contains Kimi K2 format
if !self.has_tool_markers(text) {
return Ok(vec![]);
}
let mut tools = Vec::new();
// Extract all tool calls
for captures in self.tool_call_extractor.captures_iter(text) {
if let (Some(id_match), Some(args_match)) = (
captures.name("tool_call_id"),
captures.name("function_arguments"),
) {
let function_id = id_match.as_str();
let function_args = args_match.as_str();
// Parse function ID
if let Some((func_name, _index)) = self.parse_function_id(function_id) {
// Validate JSON arguments
if serde_json::from_str::<serde_json::Value>(function_args).is_ok() {
// Generate unique ID
let id = format!("kimi_call_{}", uuid::Uuid::new_v4());
tools.push(ToolCall {
id,
r#type: "function".to_string(),
function: FunctionCall {
name: func_name,
arguments: function_args.to_string(),
},
});
}
}
}
}
Ok(tools)
}
async fn parse_incremental(
&self,
chunk: &str,
state: &mut ParseState,
) -> ToolParserResult<StreamResult> {
state.buffer.push_str(chunk);
// Check for tool markers
let has_tool_call =
self.has_tool_markers(&state.buffer) || state.buffer.contains("<|tool_call_begin|>");
if !has_tool_call {
// No markers found, clear buffer and return
state.buffer.clear();
return Ok(StreamResult::Incomplete);
}
// Try to match streaming pattern
if let Some(captures) = self.stream_tool_call_extractor.captures(&state.buffer) {
if let (Some(id_match), Some(args_match)) = (
captures.name("tool_call_id"),
captures.name("function_arguments"),
) {
let function_id = id_match.as_str();
let partial_args = args_match.as_str();
// Parse function ID
if let Some((func_name, _index)) = self.parse_function_id(function_id) {
// Send function name if not sent yet
if !state.in_string {
state.in_string = true; // Mark name as sent
return Ok(StreamResult::ToolName {
index: 0,
name: func_name.clone(),
});
}
// Check if we have a complete tool call
if let Some(end_pos) = partial_args.find("<|tool_call_end|>") {
// Extract just the JSON part
let json_args = &partial_args[..end_pos];
// Validate and parse JSON
if serde_json::from_str::<serde_json::Value>(json_args).is_ok() {
// Generate unique ID
let id = format!("kimi_call_{}", uuid::Uuid::new_v4());
let tool = ToolCall {
id,
r#type: "function".to_string(),
function: FunctionCall {
name: func_name,
arguments: json_args.to_string(),
},
};
// Find where this tool call ends in the buffer
if let Some(tool_end) = state.buffer.find("<|tool_call_end|>") {
let end_pos = tool_end + "<|tool_call_end|>".len();
state.buffer.drain(..end_pos);
}
// Reset state for next tool
state.in_string = false;
return Ok(StreamResult::ToolComplete(tool));
}
} else {
// Try to parse partial JSON for streaming arguments
match self.partial_json.parse_value(partial_args) {
Ok((value, _consumed)) => {
let args_str = serde_json::to_string(&value)
.unwrap_or_else(|_| "{}".to_string());
return Ok(StreamResult::ToolArguments {
index: 0,
arguments: args_str,
});
}
Err(_) => {
// Can't parse yet, keep buffering
}
}
}
}
}
}
Ok(StreamResult::Incomplete)
}
fn detect_format(&self, text: &str) -> bool {
self.has_tool_markers(text) || text.contains("<|tool_call_begin|>")
}
}
#[cfg(test)]
mod tests {
use super::*;
#[tokio::test]
async fn test_parse_kimi_single_tool() {
let parser = KimiK2Parser::new();
let input = r#"Some text
<|tool_calls_section_begin|>
<|tool_call_begin|>functions.get_weather:0<|tool_call_argument_begin|>{"location": "Tokyo", "units": "celsius"}<|tool_call_end|>
<|tool_calls_section_end|>More text"#;
let result = parser.parse_complete(input).await.unwrap();
assert_eq!(result.len(), 1);
assert_eq!(result[0].function.name, "get_weather");
assert!(result[0].function.arguments.contains("Tokyo"));
}
#[tokio::test]
async fn test_parse_kimi_multiple_tools() {
let parser = KimiK2Parser::new();
let input = r#"<|tool_calls_section_begin|>
<|tool_call_begin|>functions.search:0<|tool_call_argument_begin|>{"query": "rust"}<|tool_call_end|>
<|tool_call_begin|>functions.calculate:1<|tool_call_argument_begin|>{"expression": "2+2"}<|tool_call_end|>
<|tool_calls_section_end|>"#;
let result = parser.parse_complete(input).await.unwrap();
assert_eq!(result.len(), 2);
assert_eq!(result[0].function.name, "search");
assert_eq!(result[1].function.name, "calculate");
}
#[tokio::test]
async fn test_parse_kimi_with_whitespace() {
let parser = KimiK2Parser::new();
let input = r#"<|tool_calls_section_begin|>
<|tool_call_begin|> functions.test:0 <|tool_call_argument_begin|> {"key": "value"} <|tool_call_end|>
<|tool_calls_section_end|>"#;
let result = parser.parse_complete(input).await.unwrap();
assert_eq!(result.len(), 1);
assert_eq!(result[0].function.name, "test");
}
#[test]
fn test_detect_format() {
let parser = KimiK2Parser::new();
assert!(parser.detect_format("<|tool_calls_section_begin|>"));
assert!(parser.detect_format("<|tool_call_begin|>"));
assert!(!parser.detect_format("plain text"));
assert!(!parser.detect_format("[TOOL_CALLS]"));
}
}

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@@ -5,6 +5,7 @@
// Individual parser modules
pub mod deepseek_parser;
pub mod json_parser;
pub mod kimik2_parser;
pub mod llama_parser;
pub mod mistral_parser;
pub mod pythonic_parser;
@@ -13,9 +14,8 @@ pub mod step3_parser;
// Re-export parser types for convenience
pub use deepseek_parser::DeepSeekParser;
pub use json_parser::JsonParser;
pub use kimik2_parser::KimiK2Parser;
pub use llama_parser::LlamaParser;
pub use mistral_parser::MistralParser;
pub use pythonic_parser::PythonicParser;

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@@ -1,5 +1,6 @@
use crate::tool_parser::parsers::{
DeepSeekParser, JsonParser, LlamaParser, MistralParser, PythonicParser, QwenParser, Step3Parser,
DeepSeekParser, JsonParser, KimiK2Parser, LlamaParser, MistralParser, PythonicParser,
QwenParser, Step3Parser,
};
use crate::tool_parser::traits::ToolParser;
use std::collections::HashMap;
@@ -113,8 +114,12 @@ impl ParserRegistry {
// DeepSeek V3 parser - Unicode tokens with JSON blocks
self.register_parser("deepseek", Arc::new(DeepSeekParser::new()));
// Step3 parser - StepTML XML format
self.register_parser("step3", Arc::new(Step3Parser::new()));
// Kimi K2 parser - Token-based with indexed functions
self.register_parser("kimik2", Arc::new(KimiK2Parser::new()));
}
/// Register default model mappings