free-claude-code/api/request_utils.py
2026-02-15 21:58:03 -08:00

107 lines
4 KiB
Python

"""Request utility functions for API route handlers.
Contains token counting for API requests.
"""
import json
from typing import Any, List, Optional, Union
import tiktoken
from loguru import logger
ENCODER = tiktoken.get_encoding("cl100k_base")
__all__ = ["get_token_count"]
def _get_block_attr(block: Any, key: str, default: Any = "") -> Any:
"""Get attribute from block (object or dict)."""
if isinstance(block, dict):
return block.get(key, default)
return getattr(block, key, default)
def get_token_count(
messages: List,
system: Optional[Union[str, List]] = None,
tools: Optional[List] = None,
) -> int:
"""Estimate token count for a request.
Uses tiktoken cl100k_base encoding to estimate token usage.
Includes system prompt, messages, tools, and per-message overhead.
"""
total_tokens = 0
if system:
if isinstance(system, str):
total_tokens += len(ENCODER.encode(system))
elif isinstance(system, list):
for block in system:
text = _get_block_attr(block, "text", "")
if text:
total_tokens += len(ENCODER.encode(str(text)))
total_tokens += 4 # System block formatting overhead
for msg in messages:
if isinstance(msg.content, str):
total_tokens += len(ENCODER.encode(msg.content))
elif isinstance(msg.content, list):
for block in msg.content:
b_type = _get_block_attr(block, "type") or None
if b_type == "text":
text = _get_block_attr(block, "text", "")
total_tokens += len(ENCODER.encode(str(text)))
elif b_type == "thinking":
thinking = _get_block_attr(block, "thinking", "")
total_tokens += len(ENCODER.encode(str(thinking)))
elif b_type == "tool_use":
name = _get_block_attr(block, "name", "")
inp = _get_block_attr(block, "input", {})
block_id = _get_block_attr(block, "id", "")
total_tokens += len(ENCODER.encode(str(name)))
total_tokens += len(ENCODER.encode(json.dumps(inp)))
total_tokens += len(ENCODER.encode(str(block_id)))
total_tokens += 15
elif b_type == "image":
source = _get_block_attr(block, "source")
if isinstance(source, dict):
data = source.get("data") or source.get("base64") or ""
if data:
total_tokens += max(85, len(data) // 3000)
else:
total_tokens += 765
else:
total_tokens += 765
elif b_type == "tool_result":
content = _get_block_attr(block, "content", "")
tool_use_id = _get_block_attr(block, "tool_use_id", "")
if isinstance(content, str):
total_tokens += len(ENCODER.encode(content))
else:
total_tokens += len(ENCODER.encode(json.dumps(content)))
total_tokens += len(ENCODER.encode(str(tool_use_id)))
total_tokens += 8
else:
logger.debug(
"Unexpected block type %r, falling back to json/str encoding",
b_type,
)
try:
total_tokens += len(ENCODER.encode(json.dumps(block)))
except TypeError, ValueError:
total_tokens += len(ENCODER.encode(str(block)))
if tools:
for tool in tools:
tool_str = (
tool.name + (tool.description or "") + json.dumps(tool.input_schema)
)
total_tokens += len(ENCODER.encode(tool_str))
total_tokens += len(messages) * 4
if tools:
total_tokens += len(tools) * 5
return max(1, total_tokens)