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brain-of-reese/app/rag/llm.py
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ducoterra a49be80b8e
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phase: 96_oneshot_resilience
All checks complete. Final report:

**Phase 96 (one-shot resilience) — final verification pass, all green** (all 4 task files already in `complete/`; verified the working-tree implementation against the design)

- `LLMClient.chat()` empty-content retry (D1–D3) via `_chat_once` + `_EmptyContentError` (carries `finish_reason`), under `BOR_LLM_RETRIES`/`BOR_LLM_RETRY_DELAY` — verified in diff
- `missing_folder_summaries()` + `generate_folder_summaries(only_missing=…)` — verified; `folder_summary_table_empty` deleted, both sync gates switched to the gap probe
- `.env.example` comments updated (chat-turn stream + one-shot summary calls)

**Test / lint / coverage results**
- `uv run pytest --cov=app --cov-report=term-missing` → **1988 passed**, coverage **99%** (gate >90%)
- `uv run pytest tests/e2e/test_oneshot_llm_retry.py -v --no-cov` → **2 passed** (isolated)
- Regressions, each isolated: `test_ls_tree_drilldown` 3 passed, `test_sync_button` 3 passed, `test_local_directory_sources` 3 passed, `test_llm_retry` 4 passed
- `uv run ruff check . && uv run pyright` → clean (0 errors)

**Completion criteria:** retry-then-recover unit-pinned ✓ · exhaustion + `BOR_LLM_RETRIES=0` byte-identical ✓ · streaming path untouched ✓ · gap-fill both sync paths, other rows byte-identical incl. `updated_at` ✓ · no-gap zero-burn ✓ · phase E2E green ✓ · regression E2Es green ✓ · full suite + >90% + lint/types ✓ · no completed-phase behavior change (full suite green) ✓. Commit left to the harness per executor rules (working tree, 16 files).

**Deviations:** none. **Next pending phase:** `97_kb_tree_catalog`.
2026-09-11 13:16:20 -04:00

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"""Async OpenAI-compatible client for the self-hosted aipi endpoint (PLAN A5).
Provides the embeddings surface (importer, retrieval), one-shot chat
completions (phase 30: the ``lite`` model summarizes non-markdown
documents at import time), and chat streaming (PLAN A15) for the RAG
pipeline. Chat streaming yields typed :class:`StreamPiece` values
(phase 17) and — when the caller passes a ``tools`` list —
:class:`ToolCallPiece` values (phase 37): aipi's ``turbo`` model streams
its reasoning as ``delta.reasoning_content`` chunks (deepseek/litellm
wire convention, verified live 2026-08-23) **before** the answer's
``delta.content`` chunks, and reasoning counts against ``max_tokens``
(an answer can in principle be empty).
Fail-loud rule (PLAN A6): the ``chunks.embedding`` column is fixed at 768
dimensions when the table is created, so a model that returns a different
dimension must abort the import with an actionable error — never store
vectors that pgvector rejects.
"""
from __future__ import annotations
import asyncio
import json
import logging
from collections.abc import AsyncGenerator
from dataclasses import dataclass
from typing import TYPE_CHECKING, Any, Literal, cast
from openai import AsyncOpenAI, AsyncStream
from openai.types.chat import ChatCompletionChunk, ChatCompletionMessageParam
from app.config import Settings, get_settings
from app.core.errors import sanitize_error
if TYPE_CHECKING:
# Phase 71: the filter type is only needed for typing (the module
# stays import-graph-clean; callers pass their own instances).
from app.rag.scaffolding import ScaffoldingFilter
logger = logging.getLogger("app.llm")
class EmbeddingError(RuntimeError):
"""The embeddings endpoint failed (network, HTTP, or malformed reply)."""
class EmbeddingDimensionError(EmbeddingError):
"""Embedding dimension != BOR_EMBEDDING_DIM — import must fail loudly."""
class LLMError(RuntimeError):
"""The chat-completions endpoint failed (network, HTTP, or mid-stream)."""
class ModelUnavailableError(LLMError):
"""One of the models a sync needs is unreachable (phase 41 probe).
Raised by :func:`check_models` when the pre-sync probe finds the
embedding or summary model down; the message names the model so the
admin can fix the right thing.
"""
@dataclass(frozen=True)
class StreamPiece:
"""One piece of a streamed chat turn (phase 17, PLAN §4 extension).
``kind`` is ``"content"`` for answer text (an SSE ``delta`` frame)
or ``"thinking"`` for the model's reasoning (an SSE ``thinking``
frame). Frozen: pieces are immutable wire values, not accumulators.
"""
kind: Literal["content", "thinking"]
text: str
@dataclass(frozen=True)
class ToolCallPiece:
"""One model-requested tool call accumulated from stream deltas (phase 37).
``id`` is the model's tool_call id (synthesized as ``call_<index>``
when the wire never carried one), ``name`` is the function name
(whatever the caller's ``tools`` list names — for the agent loop,
``ls`` / ``read`` / ``grep``, phase 70), and ``arguments`` is the
parsed JSON object (``{}`` when the model sent none).
"""
id: str # the model's tool_call id; synthesized "call_<index>" when absent
name: str # "ls" | "read" | "grep" (whatever AGENT_TOOLS names, phase 70)
arguments: dict[str, Any]
@dataclass(frozen=True)
class ToolResultPiece:
"""One executed tool call whose result was truncated (phase 95).
A15 extension (owner permission 2026-09-10, ``TODO.md`` L5 — recorded
in the phase 95 overview ``00_phase.md``; PLAN.md is being redone by
the owner): the ``read`` tool caps its result at
``settings.read_max_chars`` (``BOR_READ_MAX_CHARS``, default 128 000
chars ≈ 32k tokens). When a document is longer than the cap, the agent
loop appends the shared ``[…truncated…]`` marker + the grep-pointer
notice to the result the model sees AND yields one of these pieces so
the API layer can surface the truncation to the user (an SSE
``tool_result`` frame, task 02). It is the ONLY piece the agent loop
yields that does not come from the model stream — it is derived from
the executed call. ``argument`` is the combined ``source/path`` the
model passed (the same value the matching ``tool`` frame carries),
``chars_shown`` is the cap (``settings.read_max_chars``) and
``chars_total`` is the document's true length — so the UI can render
"(truncated — showing N of M chars)". ``truncated`` is always ``True``
on a yielded piece (a non-truncated read yields nothing). Frozen like
its siblings: an immutable wire value.
"""
name: str # the tool that was executed (always "read" today)
argument: str | None # the model's argument (the combined source/path)
truncated: bool # always True on a yielded piece
chars_shown: int # the cap actually kept (settings.read_max_chars)
chars_total: int # the document's true length
@dataclass(frozen=True)
class RetryPiece:
"""One LLM request retry that is about to start (phase 67, locked A2).
``attempt`` is the 1-based number of the attempt that is about to be
tried — the one AFTER the attempt that just failed (a first-attempt
failure carries ``attempt=2``, so the API's SSE ``retry`` frame reads
"retrying (2 of N)" — the same convention the endpoint's embedding
retry loop uses, phase 67 task 02); ``max_attempts`` is the total
attempt budget (``llm_retries + 1``). One piece per wait: the API
layer turns it into an SSE ``retry`` frame, and it always precedes
the pre-retry sleep so the frame reaches the client before the wait
starts.
"""
attempt: int
max_attempts: int
@dataclass
class _ToolCallSlot:
"""Mutable accumulator for one streamed tool call (phase 37, private).
``id`` and ``function.name`` arrive on the first partial for an index;
``function.arguments`` arrives in fragments to concatenate (OpenAI wire
convention, verified live against aipi 2026-08-26).
"""
id: str | None = None
name: str = ""
arguments: str = ""
def _materialize_tool_calls(
slots: dict[int, _ToolCallSlot],
) -> list[ToolCallPiece]:
"""Turn accumulated slots into ordered :class:`ToolCallPiece` values.
Malformed ``arguments`` JSON raises :class:`LLMError` — a silently
dropped tool call would corrupt the agent loop (fail-loud house
style). Empty/``null`` arguments become ``{}`` (a no-parameter call
such as an unscoped ``ls``).
"""
pieces: list[ToolCallPiece] = []
for index in sorted(slots):
slot = slots[index]
raw = slot.arguments.strip()
label = slot.name or f"index {index}"
if raw:
try:
parsed: Any = json.loads(raw)
except json.JSONDecodeError as e:
raise LLMError(
f"model sent malformed tool-call arguments for '{label}': "
f"{raw[:200]!r} ({e})"
) from e
else:
parsed = None
if parsed is None:
arguments: dict[str, Any] = {}
elif isinstance(parsed, dict):
arguments = cast("dict[str, Any]", parsed)
else:
raise LLMError(
f"model sent non-object tool-call arguments for '{label}': "
f"{raw[:200]!r}"
)
pieces.append(
ToolCallPiece(
id=slot.id or f"call_{index}", name=slot.name, arguments=arguments
)
)
return pieces
# aipi's local embedding model rejects requests over ~1024 input tokens
# ("input is too large to process"). Batch by estimated tokens, with a
# safety margin under that cap — code-dense text can tokenize at ~3
# chars/token, so stay well below the ceiling. A retry that halves an
# over-large batch (:meth:`LLMClient._embed_batch`) is the backstop.
_TOKENS_PER_CHAR = 0.25
_REQUEST_TOKEN_BUDGET = 700
class _TooLarge(RuntimeError):
"""Internal: the endpoint rejected the request's input size."""
class _EmptyContentError(RuntimeError):
"""Internal: the one-shot reply parsed but carries no usable content.
Raised by :meth:`LLMClient._chat_once` for the retryable failure
class (phase 96: ``content`` None or whitespace). Carries the
reply's ``finish_reason`` (``None`` when the provider omits it) so
:meth:`LLMClient.chat` can log the greppable retry line. Never
escapes the client — ``chat()`` converts it to the public
:class:`LLMError` (D3). Not an :class:`LLMError` on purpose: callers
catching :class:`LLMError` must only ever see final, public errors.
"""
def __init__(self, message: str, finish_reason: str | None) -> None:
super().__init__(message)
self.finish_reason = finish_reason
class LLMClient:
"""Thin async wrapper over the aipi OpenAI-compatible API."""
def __init__(self, settings: Settings | None = None) -> None:
self.settings = settings or get_settings()
#: Number of embedding HTTP requests made so far (importer logging).
self.embed_batches: int = 0
self._client = AsyncOpenAI(
base_url=self.settings.llm_base_url,
api_key=self.settings.effective_api_key,
timeout=self.settings.llm_timeout,
)
async def _post_embeddings(self, texts: list[str]) -> list[list[float]]:
"""One POST /embeddings with a minimal OpenAI-compatible payload.
The ``openai`` SDK (1.x and 2.x) injects ``encoding_format`` into
every embeddings request (defaulting to ``"base64"``), and aipi's
litellm ``openai_like`` model group rejects that parameter in any
form — so we reuse the openai client's own httpx transport (same
base URL, TLS, and connection pooling) and send a clean payload.
The endpoint's default is floats, which is what pgvector needs.
"""
http = self._client._client # pyright: ignore[reportAttributeAccessIssue]
resp = await http.post(
"embeddings",
json={"model": self.settings.llm_embed_model, "input": texts},
headers={"Authorization": f"Bearer {self.settings.effective_api_key}"},
)
if resp.status_code >= 400:
if "too large" in resp.text:
raise _TooLarge(resp.text[:300])
raise EmbeddingError(
f"embeddings endpoint returned HTTP {resp.status_code}: {resp.text[:300]}"
)
payload = resp.json()
rows = payload.get("data") if isinstance(payload, dict) else None
if not isinstance(rows, list) or len(rows) != len(texts):
n = len(rows) if isinstance(rows, list) else "?"
raise EmbeddingError(
f"embeddings endpoint returned {n} vectors for {len(texts)} inputs — "
"refusing to guess which is which"
)
ordered = sorted(rows, key=lambda r: r["index"])
return [[float(x) for x in row["embedding"]] for row in ordered]
async def _embed_batch(self, chunk: list[str]) -> list[list[float]]:
"""Embed *chunk*, halving the request if the endpoint says the input
is too large (tokenizer estimates can be wrong for dense content).
A single text that still fails is a hard, actionable error."""
try:
return await self._post_embeddings(chunk)
except _TooLarge:
if len(chunk) == 1:
raise EmbeddingError(
f"a single {len(chunk[0])}-char chunk exceeded the endpoint's "
"per-request input token cap — lower BOR_CHUNK_TARGET_CHARS "
"and re-import"
) from None
mid = len(chunk) // 2
left = await self._embed_batch(chunk[:mid])
right = await self._embed_batch(chunk[mid:])
return [*left, *right]
def _check_dims(self, vecs: list[list[float]]) -> None:
expected = self.settings.embedding_dim
dims = sorted({len(v) for v in vecs})
if dims != [expected]:
raise EmbeddingDimensionError(
f"embedding dimension mismatch: model '{self.settings.llm_embed_model}' "
f"returned dims {dims} but BOR_EMBEDDING_DIM={expected}. The chunks "
"table stores a fixed dimension — run `uv run python -m scripts.llm_probe`,"
" update BOR_EMBEDDING_DIM, and recreate the schema (README → "
"Troubleshooting: 'Embedding dimension mismatch')."
)
def _batch_texts(self, texts: list[str]) -> list[list[str]]:
"""Group *texts* into requests under the endpoint's token cap.
``BOR_EMBED_BATCH_SIZE`` stays a hard cap on *texts* per request;
the token budget usually binds first for 2000-char chunks.
"""
budget_chars = int(_REQUEST_TOKEN_BUDGET / _TOKENS_PER_CHAR)
max_texts = max(1, self.settings.embed_batch_size)
batches: list[list[str]] = []
cur: list[str] = []
cur_chars = 0
for text in texts:
if cur and (len(cur) >= max_texts or cur_chars + len(text) > budget_chars):
batches.append(cur)
cur, cur_chars = [], 0
cur.append(text)
cur_chars += len(text)
if cur:
batches.append(cur)
return batches
async def embed(self, texts: list[str]) -> list[list[float]]:
"""Embed *texts* in token-budgeted batches (order always kept)."""
if not texts:
return []
out: list[list[float]] = []
for chunk in self._batch_texts(texts):
try:
vecs = await self._embed_batch(chunk)
except EmbeddingError:
raise
except Exception as e: # noqa: BLE001 — wrap transport-level failures
raise EmbeddingError(
# Phase 84 (SEC-13): a base URL configured with
# embedded ``user:pass@`` credentials must not reach
# the error string — sanitized at construction.
f"embeddings request to {sanitize_error(self.settings.llm_base_url)} "
f"failed: {e}"
) from e
self.embed_batches += 1
self._check_dims(vecs)
out.extend(vecs)
return out
async def embed_one(self, text: str) -> list[float]:
"""Convenience: embed a single text (retrieval path)."""
(vec,) = await self.embed([text])
return vec
async def _chat_once(self, messages: list[dict[str, Any]], model: str) -> str:
"""One non-streaming completion attempt (phase 96, private).
The single-attempt body of :meth:`chat` — the transport wrap
(→ :class:`LLMError` with the sanitized base URL), the choiceless
check, and the empty-content check. Raises
:class:`_EmptyContentError` (carrying the reply's
``finish_reason``) for an empty reply — the one failure class
:meth:`chat` retries — and :class:`LLMError` for everything else.
"""
try:
resp = await self._client.chat.completions.create(
model=model,
messages=cast("list[ChatCompletionMessageParam]", messages),
temperature=0.2,
max_tokens=2048,
stream=False,
)
except LLMError:
raise
except Exception as e: # noqa: BLE001 — wrap transport-level failures
raise LLMError(
# Phase 84 (SEC-13): sanitize the base URL (see embed).
f"chat completion from {sanitize_error(self.settings.llm_base_url)} "
f"failed: {e}"
) from e
if not resp.choices:
raise LLMError(
f"chat completion from {sanitize_error(self.settings.llm_base_url)} "
"returned no choices"
)
choice = resp.choices[0]
content = choice.message.content
if content is None or not content.strip():
raise _EmptyContentError(
f"chat completion from {sanitize_error(self.settings.llm_base_url)} "
"returned empty content — refusing to store a silent summary",
choice.finish_reason,
)
return content.strip()
async def chat(
self, messages: list[dict[str, Any]], model: str | None = None
) -> str:
"""One-shot (non-streaming) completion (A5 extended, phase 30).
Short, low-temperature request (``temperature=0.2``, 2048-token
cap — summaries and outlines are small, so a fixed budget is
enough) against ``BOR_LLM_SUMMARY_MODEL`` (default ``lite``)
unless *model* names another. Used by the document summarizer
(phase 30), the KB overview generator (phase 31), folder
summaries (phase 94), and the pre-sync probe
(``check_models``, phase 41).
Any transport/HTTP/malformed failure, a choiceless reply, or an
empty/missing ``content`` field raises :class:`LLMError` — a
silent empty summary must never be stored.
Empty-reply retry (phase 96, house LLM-retry policy D1–D3): the
empty-content failure class — the model answered but said
nothing (``content`` None or whitespace) — is retried up to
``settings.llm_retries`` times (``BOR_LLM_RETRIES``, default 3;
``0`` = off) with a flat ``settings.llm_retry_delay``
(``BOR_LLM_RETRY_DELAY``) between attempts, one WARNING per
retry naming the model, the reply's ``finish_reason`` (``None``
when the provider omits it), and the attempt count. After
``1 + llm_retries`` empty attempts it raises
:class:`LLMError` naming the attempts; with ``llm_retries=0``
the single-attempt message stays byte-identical to the
pre-phase-96 behavior. NO other failure retries at the app level:
a choiceless reply and transport failures raise immediately (the
openai SDK's own ``max_retries=2`` already re-POSTs wire-level
failures — an app-level transport retry would stack on top of
it).
"""
total = 1 + self.settings.llm_retries
chosen = model or self.settings.llm_summary_model
for attempt in range(1, total + 1):
try:
return await self._chat_once(messages, chosen)
except _EmptyContentError as e:
if attempt >= total:
# Retries exhausted — refuse to store the silent
# summary. total == 1 (BOR_LLM_RETRIES=0 kill switch)
# keeps the pre-phase-96 message byte-identical.
if total == 1:
raise LLMError(str(e)) from e
raise LLMError(
f"chat completion from "
f"{sanitize_error(self.settings.llm_base_url)} "
f"returned empty content on all {total} attempts — "
"refusing to store a silent summary"
) from e
logger.warning(
"one-shot LLM reply returned empty content (model=%s, "
"finish_reason=%s, attempt %d/%d) — retrying in %.1fs",
chosen,
e.finish_reason,
attempt,
total,
self.settings.llm_retry_delay,
)
# Flat delay — the phase-67 convention, no backoff.
await asyncio.sleep(self.settings.llm_retry_delay)
raise AssertionError("unreachable: every attempt returned or raised")
async def chat_stream(
self,
messages: list[dict[str, Any]],
tools: list[dict[str, Any]] | None = None,
scaffolding: ScaffoldingFilter | None = None,
) -> AsyncGenerator[StreamPiece | ToolCallPiece, None]:
"""Stream assistant pieces from the chat model (PLAN A5/A15, phase 17).
Messages are passed to the request body VERBATIM: string-only
``{role, content}`` dicts are byte-identical on the wire to the
pre-phase-74 requests, and an assistant message may additionally
carry ``reasoning_content`` (the client's prior thinking, phase
74 — the same wire field the model uses for its OWN reasoning on
the response side; the ``openai`` SDK passes message dicts
through untouched, so no transport change).
``stream=True`` against the OpenAI-compatible endpoint, yielding
typed :class:`StreamPiece` values. Wire convention (verified live
against aipi's ``turbo`` on 2026-08-23): the model's reasoning
arrives as ``delta.reasoning_content`` chunks (deepseek/litellm
convention) **before** the first ``delta.content`` chunk, so in
practice thinking pieces precede content pieces. The ``openai``
SDK keeps unknown delta fields in ``model_extra``, so ``getattr``
is the right accessor — no raw-HTTP parsing is needed. A chunk
carrying both fields yields the thinking piece **first**.
Reasoning counts against ``max_tokens``: an answer can in principle
be empty (thinking with no content) — the UI handles that.
Answers are allowed up to ``BOR_MAX_OUTPUT_TOKENS`` (default
32 768) output tokens — the old hard 700-token cap cut long
answers off mid-sentence (owner report 2026-08-22).
Tool calls (phase 37): when *tools* (an OpenAI ``tools`` list) is
not None it is passed through as ``tools=…``; when None the key is
**not** included, so the request is byte-identical to pre-phase-37
and no tool pieces can be produced. A tool-calling model replies
with ``delta.tool_calls`` partials — keyed by ``index``, with
``id`` and ``function.name`` on the first partial and
``function.arguments`` in fragments — which are accumulated into
one :class:`ToolCallPiece` per call, yielded in index order at
stream end (after the stream's chunks are exhausted — aipi ends
the stream at ``finish_reason="tool_calls"``, so this is the
wire's emission point). Malformed ``arguments`` JSON raises
:class:`LLMError`. Wire convention verified live against
aipi's ``turbo`` on 2026-08-26 via
``uv run python -m scripts.llm_probe --tools`` (phase 37, task 01:
``probe: turbo tool_calls=supported 2026-08-26``).
Scaffolding guardrail (phase 71): the caller may pass a
``ScaffoldingFilter`` — one per request, caller-owned (this
method never creates or resets one). When present, only
**content** is filtered: ``delta.content`` is fed through the
filter and only the clean text is yielded (an empty clean
result yields **no** piece — no empty ``delta`` frames); thinking
pieces are never filtered (the scratchpad stays raw, phase 17).
At stream end the filter's held tail is flushed to a content
piece **before** any tool-call materialization (content-
before-tools wire convention). ``None`` (the default) keeps
today's byte-identical raw path for callers that opt out.
Any failure (network, HTTP, malformed stream) surfaces as
:class:`LLMError` so the API layer can turn it into an SSE
``error`` event instead of a hung request.
Teardown (phase 48, 2026-08-29, ``TODO.md`` L3): once
``create()`` succeeded, the endpoint stream's lifetime is
explicit — it is closed on **every** exit: normal exhaustion
(a quiet no-op on the already-ended SDK stream, so the
completed path stays byte-identical), a wrapped mid-stream
failure, and consumer abandon (stop/cancel — ``GeneratorExit``;
awaiting in the ``finally`` is safe because it does not yield).
The SDK's ``close()`` awaits the underlying httpx response's
``aclose()``, so the local model stops generating as soon as
the SSE consumer goes away.
"""
kwargs: dict[str, Any] = {
# ``{role, content}`` dicts are exactly what the message params
# accept; the cast keeps pyright honest about the SDK's union.
"model": self.settings.llm_chat_model,
"messages": cast("list[ChatCompletionMessageParam]", messages),
"temperature": 0.4,
"max_tokens": self.settings.max_output_tokens,
"stream": True,
}
if tools is not None:
kwargs["tools"] = tools
stream: AsyncStream[ChatCompletionChunk] | None = None
try:
stream = cast(
"AsyncStream[ChatCompletionChunk]",
await self._client.chat.completions.create(**kwargs),
)
calls: dict[int, _ToolCallSlot] = {}
async for chunk in stream:
if not chunk.choices:
continue
choice = chunk.choices[0]
delta = choice.delta
# Tool-call partials (phase 37) accumulate across chunks,
# keyed by index; a missing index (not seen on aipi) falls
# back to the next synthetic slot.
for tc in getattr(delta, "tool_calls", None) or []:
idx = getattr(tc, "index", None)
key = idx if isinstance(idx, int) else (max(calls) + 1 if calls else 0)
slot = calls.setdefault(key, _ToolCallSlot())
tc_id = getattr(tc, "id", None)
if tc_id and slot.id is None:
slot.id = tc_id
fn = getattr(tc, "function", None)
if fn is not None:
if fn.name:
slot.name += fn.name
if fn.arguments:
slot.arguments += fn.arguments
reasoning = getattr(delta, "reasoning_content", None)
if not reasoning:
# Future-proofing: the same wire convention under a
# shorter field name.
reasoning = getattr(delta, "reasoning", None)
if reasoning:
yield StreamPiece("thinking", reasoning)
content = delta.content
if content:
if scaffolding is not None:
# Phase 71: content only — an empty clean result
# yields nothing (no empty delta frames).
cleaned = scaffolding.feed(content)
if cleaned:
yield StreamPiece("content", cleaned)
else:
yield StreamPiece("content", content)
# Phase 71: flush the filter's held tail at stream end, BEFORE
# any tool-call materialization — flushed-tail content precedes
# ToolCallPieces (content-before-tools wire convention).
if scaffolding is not None:
tail = scaffolding.flush()
if tail:
yield StreamPiece("content", tail)
if calls:
for piece in _materialize_tool_calls(calls):
yield piece
except LLMError:
raise
except Exception as e: # noqa: BLE001 — wrap transport-level failures
# Phase 84 (SEC-13): sanitize the base URL (see embed).
raise LLMError(
f"chat stream from {sanitize_error(self.settings.llm_base_url)} failed: {e}"
) from e
finally:
# Phase 48: deterministic teardown — whenever ``create()``
# succeeded, close the endpoint's stream on every subsequent
# exit (normal exhaustion, wrapped failures, and consumer
# abandon). A failure of ``create()`` itself never sets
# ``stream``, so it stays the plain wrap above.
if stream is not None:
await stream.close()
async def chat_stream_retried(
llm: LLMClient,
messages: list[dict[str, Any]],
*,
tools: list[dict[str, Any]] | None = None,
retries: int = 0,
delay: float = 0.0,
scaffolding: ScaffoldingFilter | None = None,
) -> AsyncGenerator[StreamPiece | ToolCallPiece | RetryPiece, None]:
"""Stream a chat turn, retrying a dead endpoint (phase 67).
Wraps :meth:`LLMClient.chat_stream` with the retry-before-first-piece
rule (owner-locked A2): a request is restarted **only** while no output
piece (thinking/tool/delta) has been yielded for it. Once pieces have
flowed, an :class:`LLMError` is re-raised unchanged — a partial answer
is never redone, and the API layer's terminal ``error`` frame applies.
This primitive is the ONLY place that rule lives (the chat endpoint
and the agent loop both build on it).
Up to *retries* restarts after the initial attempt (``retries + 1``
attempts total; ``retries=0`` is exactly one attempt with no
:class:`RetryPiece` — the pre-phase-67 kill-switch path). Each restart
is preceded by one :class:`RetryPiece` (``attempt`` = the 1-based
number of the attempt about to be tried — the failed attempt + 1 —
and ``max_attempts`` = ``retries + 1``) and a flat
``asyncio.sleep(delay)`` — the TODO-locked fixed interval, no
backoff. The ``RetryPiece`` always precedes its sleep: the API frame
must reach the client before the wait starts.
The request is restarted byte-identical: ``chat_stream`` is stateless,
so every attempt is opened with the SAME *messages*/*tools*.
Scaffolding guardrail (phase 71): *scaffolding* is passed through to
every attempt's ``chat_stream``. The SAME caller-owned filter object
across the retry attempts of one logical request is safe by
construction: a restarted attempt only happens while no piece was
emitted, i.e. the filter was never fed (its pending buffer is still
empty).
Teardown (phase 48, extended): every attempt's stream is explicitly
closed in a ``finally`` — normal exhaustion, a terminal
:class:`LLMError`, and a consumer abandon (``GeneratorExit`` mid-attempt
or during the pre-retry sleep) all run it, so an abandoned turn never
leaves the endpoint's stream open.
"""
max_attempts = retries + 1
for attempt in range(1, max_attempts + 1):
emitted = False
stream = llm.chat_stream(messages, tools=tools, scaffolding=scaffolding)
try:
async for piece in stream:
emitted = True
yield piece
except LLMError as e:
if emitted:
# Locked A2: tokens already flowed — the failure is
# terminal, never redo a partial answer.
raise
if attempt >= max_attempts:
# Retries exhausted — the API layer turns this into the
# terminal error frame.
raise
logger.warning(
"llm stream failed before the first piece (attempt %d/%d) — "
"retrying in %.1fs: %s",
attempt,
max_attempts,
delay,
e,
)
yield RetryPiece(attempt + 1, max_attempts)
await asyncio.sleep(delay)
else:
# A fully consumed attempt — the turn is done; the loop must
# NOT open another stream for an attempt that never failed.
return
finally:
# Phase 48 teardown for THIS attempt's stream (a no-op once the
# stream already ended; the real close on a consumer abandon).
await stream.aclose()
async def check_models(llm: LLMClient) -> None:
"""Verify the models a sync needs (embed + summary) before any
expensive work; raise ModelUnavailableError naming the model.
The probe is deliberately tiny — one short embedding
(``sync model check``) and one 1-token-scale completion (``ping``)
— so a dead endpoint is discovered cheaper than a single git
clone. The sync sanitizer downstream (``app.api.sync
._sanitize_error``) still masks any credentials embedded in the
wrapped error text, so the raw endpoint URL in the original
exception is safe to include.
"""
embed_model = llm.settings.llm_embed_model
try:
await llm.embed_one("sync model check")
except Exception as e: # noqa: BLE001 — wrap EmbeddingError + transport failures
raise ModelUnavailableError(
f"The embedding model ('{embed_model}') is not available — "
f"check the model endpoint and retry. ({e})"
) from e
summary_model = llm.settings.llm_summary_model
try:
await llm.chat([{"role": "user", "content": "ping"}])
except Exception as e: # noqa: BLE001 — wrap LLMError + transport failures
raise ModelUnavailableError(
f"The summary model ('{summary_model}') is not available — "
f"check the model endpoint and retry. ({e})"
) from e