Files
hermes-agent/environments/tool_call_parsers/mistral_parser.py

136 lines
5.1 KiB
Python

"""
Mistral tool call parser.
Supports two formats depending on tokenizer version:
- Pre-v11: content[TOOL_CALLS] [{"name": ..., "arguments": {...}}, ...]
- v11+: content[TOOL_CALLS]tool_name1{"arg": "val"}[TOOL_CALLS]tool_name2{"arg": "val"}
Based on VLLM's MistralToolParser.extract_tool_calls()
The [TOOL_CALLS] token is the bot_token used by Mistral models.
"""
import json
import uuid
from typing import List, Optional
from openai.types.chat.chat_completion_message_tool_call import (
ChatCompletionMessageToolCall,
Function,
)
from environments.tool_call_parsers import ParseResult, ToolCallParser, register_parser
def _generate_mistral_id() -> str:
"""Mistral tool call IDs are 9-char alphanumeric strings."""
import random
import string
return "".join(random.choices(string.ascii_letters + string.digits, k=9))
@register_parser("mistral")
class MistralToolCallParser(ToolCallParser):
"""
Parser for Mistral-format tool calls.
Detects format by checking if the content after [TOOL_CALLS] starts with '['
(pre-v11 JSON array) or with a tool name (v11+ format).
"""
# The [TOOL_CALLS] token -- may appear as different strings depending on tokenizer
BOT_TOKEN = "[TOOL_CALLS]"
def parse(self, text: str) -> ParseResult:
if self.BOT_TOKEN not in text:
return text, None
try:
parts = text.split(self.BOT_TOKEN)
content = parts[0].strip()
raw_tool_calls = parts[1:]
# Detect format: if the first raw part starts with '[', it's pre-v11
first_raw = raw_tool_calls[0].strip() if raw_tool_calls else ""
is_pre_v11 = first_raw.startswith("[") or first_raw.startswith("{")
tool_calls: List[ChatCompletionMessageToolCall] = []
if not is_pre_v11:
# v11+ format: [TOOL_CALLS]tool_name{args}[TOOL_CALLS]tool_name2{args2}
for raw in raw_tool_calls:
raw = raw.strip()
if not raw or "{" not in raw:
continue
brace_idx = raw.find("{")
tool_name = raw[:brace_idx].strip()
args_str = raw[brace_idx:]
# Validate and clean the JSON arguments
try:
parsed_args = json.loads(args_str)
args_str = json.dumps(parsed_args, ensure_ascii=False)
except json.JSONDecodeError:
pass # Keep raw if parsing fails
tool_calls.append(
ChatCompletionMessageToolCall(
id=_generate_mistral_id(),
type="function",
function=Function(name=tool_name, arguments=args_str),
)
)
else:
# Pre-v11 format: [TOOL_CALLS] [{"name": ..., "arguments": {...}}]
try:
parsed = json.loads(first_raw)
if isinstance(parsed, dict):
parsed = [parsed]
for tc in parsed:
args = tc.get("arguments", {})
if isinstance(args, dict):
args = json.dumps(args, ensure_ascii=False)
tool_calls.append(
ChatCompletionMessageToolCall(
id=_generate_mistral_id(),
type="function",
function=Function(
name=tc["name"], arguments=args
),
)
)
except json.JSONDecodeError:
# Fallback: extract JSON objects using raw_decode
decoder = json.JSONDecoder()
idx = 0
while idx < len(first_raw):
try:
obj, end_idx = decoder.raw_decode(first_raw, idx)
if isinstance(obj, dict) and "name" in obj:
args = obj.get("arguments", {})
if isinstance(args, dict):
args = json.dumps(args, ensure_ascii=False)
tool_calls.append(
ChatCompletionMessageToolCall(
id=_generate_mistral_id(),
type="function",
function=Function(
name=obj["name"], arguments=args
),
)
)
idx = end_idx
except json.JSONDecodeError:
idx += 1
if not tool_calls:
return text, None
return content if content else None, tool_calls
except Exception:
return text, None