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mcp-nextcloud/nextcloud_mcp_server/providers/openai.py
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Chris CoutinhoandClaude Opus 4.8 a0bb5642cb fix(usage): embed query once across doc_types; address review round 1
Round-1 claude-review findings:

- 🔴 Multi-doc_type search billed N embedding calls as 1. nc_semantic_search
  loops search() once per doc_type on one BM25HybridSearchAlgorithm instance,
  and each call re-embedded the query, so only the last query_token_count was
  recorded. Cache the dense embedding per query on the (per-request) instance
  so the query is embedded — and metered — exactly once regardless of how many
  doc_types are searched. This also removes the redundant per-type embed work
  and avoids billing a user N× for one logical query.
- 🟡 Ollama embed() now delegates to embed_with_usage() so single and batch
  embeds use the same /api/embed endpoint (was the legacy /api/embeddings),
  keeping _detect_dimension and other embed() callers consistent.
- 🟢 round() instead of truncating int() when coercing provider-reported token
  counts (forward-compatible if a provider ever returns a float).

Tests: per-instance query-embedding cache (embedded once across 3 doc_types;
re-embeds on a different query).

Deferred (stated on the PR): mistral/openai single-embed dual path (changes
tested error/request semantics on the cloud-critical path — separate refactor),
bedrock boto3 sync-in-async (pre-existing; no new invoke_model calls per doc).

Deck #67.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-08 01:07:22 +02:00

297 lines
9.8 KiB
Python

"""Unified OpenAI provider for embeddings and text generation.
Supports:
- OpenAI's standard API
- GitHub Models API (models.github.ai)
- Any OpenAI-compatible API via base_url override
"""
import logging
from openai import AsyncOpenAI, RateLimitError
from ._retry import retry_on_rate_limit
from .base import Provider
logger = logging.getLogger(__name__)
# OpenAI's RateLimitError is itself a 429-specific class, so the default
# is_rate_limit predicate ("always True") matches the previous behavior.
_retry_429 = retry_on_rate_limit(RateLimitError, provider_name="OpenAI")
# Well-known embedding dimensions for OpenAI models
OPENAI_EMBEDDING_DIMENSIONS: dict[str, int] = {
"text-embedding-3-small": 1536,
"text-embedding-3-large": 3072,
"text-embedding-ada-002": 1536,
# GitHub Models API uses openai/ prefix
"openai/text-embedding-3-small": 1536,
"openai/text-embedding-3-large": 3072,
}
class OpenAIProvider(Provider):
"""
OpenAI provider supporting both embeddings and text generation.
Works with:
- OpenAI's standard API (api.openai.com)
- GitHub Models API (models.github.ai)
- Any OpenAI-compatible API (via base_url)
"""
def __init__(
self,
api_key: str,
base_url: str | None = None,
embedding_model: str | None = None,
generation_model: str | None = None,
timeout: float = 120.0,
):
"""
Initialize OpenAI provider.
Args:
api_key: OpenAI API key (or GITHUB_TOKEN for GitHub Models)
base_url: Base URL override (e.g., "https://models.github.ai/inference")
embedding_model: Model for embeddings (e.g., "text-embedding-3-small").
None disables embeddings.
generation_model: Model for text generation (e.g., "gpt-4o-mini").
None disables generation.
timeout: HTTP timeout in seconds (default: 120)
"""
self.embedding_model = embedding_model
self.generation_model = generation_model
self._dimension: int | None = None
# Initialize async client
self.client = AsyncOpenAI(
api_key=api_key,
base_url=base_url,
timeout=timeout,
)
# Try to get known dimension without API call
if embedding_model and embedding_model in OPENAI_EMBEDDING_DIMENSIONS:
self._dimension = OPENAI_EMBEDDING_DIMENSIONS[embedding_model]
logger.info(
"Initialized OpenAI provider: base_url=%s "
"(embedding_model=%s, generation_model=%s, dimension=%s)",
base_url or "default",
embedding_model,
generation_model,
self._dimension,
)
@property
def supports_embeddings(self) -> bool:
"""Whether this provider supports embedding generation."""
return self.embedding_model is not None
@property
def supports_generation(self) -> bool:
"""Whether this provider supports text generation."""
return self.generation_model is not None
@_retry_429
async def embed(self, text: str) -> list[float]:
"""
Generate embedding vector for text.
Args:
text: Input text to embed
Returns:
Vector embedding as list of floats
Raises:
NotImplementedError: If embeddings not enabled (no embedding_model)
"""
if not self.supports_embeddings:
raise NotImplementedError(
"Embedding not supported - no embedding_model configured"
)
assert self.embedding_model is not None # Type narrowing
response = await self.client.embeddings.create(
input=text,
model=self.embedding_model,
)
embedding = response.data[0].embedding
# Update dimension if not set
if self._dimension is None:
self._dimension = len(embedding)
logger.info(
"Detected embedding dimension: %d for model %s",
self._dimension,
self.embedding_model,
)
return embedding
async def embed_batch(self, texts: list[str]) -> list[list[float]]:
"""
Generate embeddings for multiple texts using OpenAI's batch API.
OpenAI supports up to 2048 inputs per request.
Args:
texts: List of texts to embed
Returns:
List of vector embeddings
Raises:
NotImplementedError: If embeddings not enabled (no embedding_model)
"""
if not self.supports_embeddings:
raise NotImplementedError(
"Embedding not supported - no embedding_model configured"
)
embeddings, _ = await self.embed_batch_with_usage(texts)
return embeddings
async def embed_with_usage(self, text: str) -> tuple[list[float], int]:
"""Embed one text, reporting the request's token count."""
embeddings, tokens = await self.embed_batch_with_usage([text])
if not embeddings:
raise RuntimeError(
"OpenAI embeddings API returned no embedding for model "
f"{self.embedding_model}"
)
return embeddings[0], tokens
async def embed_batch_with_usage(
self, texts: list[str]
) -> tuple[list[list[float]], int]:
"""Embed multiple texts, summing the API-reported token usage.
Returns ``(embeddings, total_tokens)`` where ``total_tokens`` sums
``response.usage.total_tokens`` across the sub-requests (the unit the
provider bills on). Used by the usage-metering hooks (Deck #67). Also
serves the gateway path via :class:`GatewayProvider`.
"""
if not self.supports_embeddings:
raise NotImplementedError(
"Embedding not supported - no embedding_model configured"
)
if not texts:
return [], 0
# OpenAI supports batches up to 2048, but use smaller batches for safety
batch_size = 100
all_embeddings: list[list[float]] = []
total_tokens = 0
for i in range(0, len(texts), batch_size):
batch = texts[i : i + batch_size]
# Use helper method with retry logic for each batch
batch_embeddings, batch_tokens = await self._embed_batch_request(batch)
all_embeddings.extend(batch_embeddings)
total_tokens += batch_tokens
# Update dimension if not set
if self._dimension is None and batch_embeddings:
self._dimension = len(batch_embeddings[0])
logger.info(
"Detected embedding dimension: %d for model %s",
self._dimension,
self.embedding_model,
)
return all_embeddings, total_tokens
@_retry_429
async def _embed_batch_request(
self, batch: list[str]
) -> tuple[list[list[float]], int]:
"""Make a single batch embedding request with retry logic.
Returns ``(embeddings, token_count)``; ``token_count`` comes from the
response's ``usage.total_tokens`` and falls back to a char-based
estimate if the API omits usage.
"""
assert self.embedding_model is not None # Type narrowing
response = await self.client.embeddings.create(
input=batch,
model=self.embedding_model,
)
# Sort by index to maintain order
sorted_data = sorted(response.data, key=lambda x: x.index)
embeddings = [item.embedding for item in sorted_data]
usage = getattr(response, "usage", None)
total_tokens = getattr(usage, "total_tokens", None) if usage else None
# Guard on numeric type (not just ``is not None``): a real response
# gives an int, but test doubles / partial responses can surface a
# non-numeric attribute — fall back to the estimate there.
tokens = (
round(total_tokens)
if isinstance(total_tokens, (int, float))
else self._estimate_tokens(batch)
)
return embeddings, tokens
def get_dimension(self) -> int:
"""
Get embedding dimension.
Returns:
Vector dimension for the configured embedding model
Raises:
NotImplementedError: If embeddings not enabled (no embedding_model)
RuntimeError: If dimension not detected yet (call embed first)
"""
if not self.supports_embeddings:
raise NotImplementedError(
"Embedding not supported - no embedding_model configured"
)
if self._dimension is None:
raise RuntimeError(
f"Embedding dimension not detected yet for model {self.embedding_model}. "
"Call embed() first or use a known model."
)
return self._dimension
@_retry_429
async def generate(self, prompt: str, max_tokens: int = 500) -> str:
"""
Generate text from a prompt.
Args:
prompt: The prompt to generate from
max_tokens: Maximum tokens to generate
Returns:
Generated text
Raises:
NotImplementedError: If generation not enabled (no generation_model)
"""
if not self.supports_generation:
raise NotImplementedError(
"Text generation not supported - no generation_model configured"
)
response = await self.client.chat.completions.create(
model=self.generation_model,
messages=[{"role": "user", "content": prompt}],
max_tokens=max_tokens,
temperature=0.7,
)
return response.choices[0].message.content or ""
async def close(self) -> None:
"""Close HTTP client."""
await self.client.close()