Files
strix/strix/llm/context_budget.py
T
chunguscodes 76e97e6a59 fix(llm): avoid auth during ChatGPT lookup
LiteLLM treats provider-qualified metadata lookups as an auth path.
Use the underlying model slug so context sizing cannot block the scan
loop in a device-code poll.
2026-07-31 03:45:41 +03:00

88 lines
2.8 KiB
Python

"""Model-aware token budgets, resolved from LiteLLM model metadata with a
large configurable fallback for models LiteLLM doesn't map.
"""
from __future__ import annotations
import logging
from functools import lru_cache
from typing import Any
import litellm
from strix.config import load_settings
logger = logging.getLogger(__name__)
# LiteLLM keys models without the routing prefix users type (``openai/``,
# ``litellm/``, ``ollama/`` ...). Strip a leading provider segment on lookup.
_STRIPPABLE_PREFIXES = (
"openai/",
"chatgpt/",
"litellm/",
"any-llm/",
"ollama/",
"ollama_chat/",
)
_DEFAULT_OUTPUT_TOKENS = 8_192
def _lookup_key(model: str) -> str:
for prefix in _STRIPPABLE_PREFIXES:
if model.startswith(prefix):
return model[len(prefix) :]
return model
def _safe_get_model_info(model: str) -> dict[str, Any] | None:
try:
return dict(litellm.get_model_info(model))
except Exception: # noqa: BLE001 - unmapped models raise; caller falls back.
return None
@lru_cache(maxsize=128)
def _model_info(model: str) -> dict[str, int]:
lookup_key = _lookup_key(model)
# Provider-qualified ChatGPT lookups may start a synchronous device-login
# poll. LiteLLM keys the metadata by the underlying model slug.
candidates = (lookup_key,) if model.startswith("chatgpt/") else (model, lookup_key)
for candidate in candidates:
info = _safe_get_model_info(candidate)
if info is not None:
return {
"max_input_tokens": int(
info.get("max_input_tokens") or info.get("max_tokens") or 0
),
"max_output_tokens": int(info.get("max_output_tokens") or 0),
}
logger.debug("No LiteLLM model info for %r; using configured fallbacks", model)
return {"max_input_tokens": 0, "max_output_tokens": 0}
def context_window(model: str) -> int:
"""Input token capacity for ``model`` (configured fallback when unmapped)."""
resolved = _model_info(model)["max_input_tokens"]
return resolved or load_settings().context.fallback_context_tokens
def output_limit(model: str) -> int:
"""Max output tokens for ``model`` (a conservative default when unmapped)."""
return _model_info(model)["max_output_tokens"] or _DEFAULT_OUTPUT_TOKENS
def count_tokens(model: str, text: str) -> int:
"""Token count for ``text`` under ``model``.
Falls back to UTF-8 byte length (a guaranteed upper bound) when LiteLLM
can't count, so budget checks stay conservative.
"""
if not text:
return 0
try:
return int(litellm.token_counter(model=_lookup_key(model), text=text))
except Exception: # noqa: BLE001 - tokenizer may be unavailable for some models.
return len(text.encode("utf-8"))