Files
chat/chat/llm/featherless.py
T
Joseph Doherty b3d78c1603 docs: clarify FeatherlessClient.embed() rationale (verified 500 + empty embedding catalog)
Updates the docstring + test docstring for the NotImplementedError stub
shipped in T112 (Phase 4.5). Original wording said Featherless 'does
not expose /v1/embeddings'; verified the endpoint actually responds
but always returns HTTP 500 with type='completions_error' for every
model tried (text-embedding-3-small, BAAI/bge-small-en-v1.5,
sentence-transformers/all-MiniLM-L6-v2, etc.) and /v1/models has no
embedding-class entries. Stub behavior unchanged.
2026-04-27 11:39:53 -04:00

87 lines
3.7 KiB
Python

from __future__ import annotations
import asyncio
from typing import AsyncIterator, Sequence
from openai import AsyncOpenAI
from .client import Message
class FeatherlessClient:
"""Client for Featherless's OpenAI-compatible API.
Featherless caps concurrent connections per account (2 on free / lower
paid tiers). A class-level semaphore gates every ``generate`` and
``stream`` call so the orchestrator never exceeds the configured cap,
regardless of how many ``FeatherlessClient`` instances are alive.
Configure once at app startup via :meth:`configure_concurrency`. The
default is 2.
"""
_semaphore: asyncio.Semaphore | None = None
@classmethod
def configure_concurrency(cls, max_concurrent: int) -> None:
cls._semaphore = asyncio.Semaphore(max(1, int(max_concurrent)))
@classmethod
def _sem(cls) -> asyncio.Semaphore:
if cls._semaphore is None:
cls._semaphore = asyncio.Semaphore(2)
return cls._semaphore
def __init__(self, api_key: str, base_url: str = "https://api.featherless.ai/v1"):
self._client = AsyncOpenAI(api_key=api_key, base_url=base_url)
async def generate(self, messages: Sequence[Message], *, model: str, **params) -> str:
async with self._sem():
resp = await self._client.chat.completions.create(
model=model,
messages=[{"role": m.role, "content": m.content} for m in messages],
**params,
)
return resp.choices[0].message.content or ""
async def stream(self, messages: Sequence[Message], *, model: str, **params) -> AsyncIterator[str]:
async with self._sem():
stream = await self._client.chat.completions.create(
model=model,
messages=[{"role": m.role, "content": m.content} for m in messages],
stream=True,
**params,
)
async for chunk in stream:
delta = chunk.choices[0].delta.content or ""
if delta:
yield delta
async def embed(self, text: str, *, model: str) -> list[float]:
"""Embeddings via Featherless — unsupported in practice.
T112 (Phase 4.5) extends the LLMClient Protocol with ``embed()``
for a future real-embedding swap. Featherless's OpenAI-compatible
surface routes ``/v1/embeddings`` (no 404), but every request
returns HTTP 500 ``{"error": {"type": "completions_error", ...}}``
— including standard names like ``text-embedding-3-small`` and
``BAAI/bge-small-en-v1.5``. ``/v1/models`` confirms it: the
catalog has no embedding-class entries, only chat/completion
classes (``llama3-*``, ``gemma3-*``, ``glm5-*``, etc.).
Rather than ship a request that always 500s, this implementation
raises ``NotImplementedError``. The
:func:`chat.services.embeddings.generate_embedding` wrapper
catches it and degrades to the existing zero-vector fallback
(with the T107 warning), so misconfigured callers fail loudly in
logs but the request path keeps working.
For real embeddings, configure a different provider (OpenAI
direct, Cohere, Voyage, Together, self-hosted Ollama /
sentence-transformers). The Mock + routing seam from T112 keeps
the swap to a one-class change in ``chat/llm/``.
"""
raise NotImplementedError(
"Featherless /v1/embeddings always returns 500 "
'("completions_error") and the model catalog has no '
"embedding class; configure a different embedding provider "
"or stick with the default pseudo-sha256-384 model."
)