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nanobot/nanobot/providers/base.py
T

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67 KiB
Python

"""Base LLM provider interface."""
from __future__ import annotations
import asyncio
import json
import os
import re
import time
from abc import ABC, abstractmethod
from collections.abc import Awaitable, Callable
from contextlib import suppress
from copy import deepcopy
from dataclasses import dataclass, field
from datetime import datetime, timezone
from email.utils import parsedate_to_datetime
from typing import TYPE_CHECKING, Any, Literal, cast
import json_repair
from loguru import logger
from nanobot.utils.helpers import sanitize_surrogates_deep
if TYPE_CHECKING:
from nanobot.llm_usage.models import LLMCallRecord
STREAM_IDLE_TIMEOUT_ENV = "NANOBOT_STREAM_IDLE_TIMEOUT_S"
DEFAULT_STREAM_IDLE_TIMEOUT_S = 90.0
MAX_STREAM_IDLE_TIMEOUT_S = 3600.0
RETRY_AFTER_BUFFER = 1
RetryEventCallback = Callable[[str], Awaitable[None]]
LLMCallObserver = Callable[["LLMCallRecord"], None]
def resolve_stream_idle_timeout_s(
*,
env_value: str | None = None,
default: float = DEFAULT_STREAM_IDLE_TIMEOUT_S,
maximum: float = MAX_STREAM_IDLE_TIMEOUT_S,
) -> float:
"""Return a safe streaming idle timeout from env/config text."""
raw = os.environ.get(STREAM_IDLE_TIMEOUT_ENV) if env_value is None else env_value
if raw is None or not raw.strip():
return default
try:
value = float(raw)
except (TypeError, ValueError):
logger.warning("Ignoring invalid {}={!r}; using {}", STREAM_IDLE_TIMEOUT_ENV, raw, default)
return default
if value <= 0:
logger.warning("Ignoring non-positive {}={!r}; using {}", STREAM_IDLE_TIMEOUT_ENV, raw, default)
return default
if value > maximum:
logger.warning("Clamping {}={!r} to {}", STREAM_IDLE_TIMEOUT_ENV, raw, maximum)
return maximum
return value
@dataclass
class ToolCallRequest:
"""A tool call request from the LLM."""
id: str
name: str
arguments: Any
extra_content: dict[str, Any] | None = None
provider_specific_fields: dict[str, Any] | None = None
function_provider_specific_fields: dict[str, Any] | None = None
def has_valid_name(self) -> bool:
"""Whether this call carries a usable (non-empty string) tool name.
ToolCallRequest.name is typed ``str`` but not enforced at runtime: a
model/gateway can emit a degenerate call with ``name=None`` or ``""``.
Such a call cannot be executed and, if persisted and replayed, makes
upstream APIs reject the whole request (e.g. Anthropic-style
``messages.content.N.tool_use.name: Input should be a valid string``),
which permanently wedges the session.
"""
runtime_name = cast(object, self.name)
return isinstance(runtime_name, str) and bool(runtime_name)
def to_openai_tool_call(self) -> dict[str, Any]:
"""Serialize to an OpenAI-style tool_call payload."""
arguments = (
self.arguments
if isinstance(self.arguments, str)
else json.dumps(self.arguments, ensure_ascii=False)
)
tool_call: dict[str, Any] = {
"id": self.id,
"type": "function",
"function": {
"name": self.name,
"arguments": arguments,
},
}
if self.extra_content:
tool_call["extra_content"] = self.extra_content
if self.provider_specific_fields:
tool_call["provider_specific_fields"] = self.provider_specific_fields
if self.function_provider_specific_fields:
tool_call["function"]["provider_specific_fields"] = self.function_provider_specific_fields
return tool_call
def parse_tool_arguments(arguments: Any) -> Any:
"""Parse provider tool arguments without guessing executable parameters.
Valid JSON object strings become dicts. Empty strings become no-arg calls.
Malformed JSON and JSON array/scalar values are preserved so ToolRegistry
can reject them before execution.
"""
if arguments is None:
return {}
if not isinstance(arguments, str):
return arguments
stripped = arguments.strip()
if not stripped:
return {}
try:
parsed = json.loads(stripped)
except Exception:
return arguments
return arguments if parsed is None else parsed
def tool_arguments_object_for_replay(arguments: Any) -> dict[str, Any]:
"""Return object-shaped arguments for provider history replay only.
This compatibility path may repair malformed JSON because it only shapes
existing conversation history for provider protocols. Do not use it for
newly generated tool calls that are about to execute.
"""
if arguments is None:
return {}
if isinstance(arguments, dict):
return cast(dict[str, Any], arguments)
if not isinstance(arguments, str):
return {}
stripped = arguments.strip()
if not stripped:
return {}
try:
parsed = json.loads(stripped)
except Exception:
try:
parsed = json_repair.loads(stripped)
except Exception:
return {}
return cast(dict[str, Any], parsed) if isinstance(parsed, dict) else {}
def tool_arguments_json_for_replay(arguments: Any) -> str:
"""Return JSON object string arguments for provider history replay only."""
return json.dumps(tool_arguments_object_for_replay(arguments), ensure_ascii=False)
@dataclass
class ProviderConversationState:
"""Opaque provider-owned continuation state.
``payload`` may contain encrypted reasoning or other provider-private
protocol items. Keep it out of normal logs and public chat history.
``pending_messages`` are Chat-style messages produced after the most
recent provider response and are materialized by the owning provider on
the next request.
"""
kind: str
provider: str
model: str
version: int
payload: dict[str, Any] = field(default_factory=dict, repr=False)
pending_messages: list[dict[str, Any]] = field(default_factory=list, repr=False)
def with_pending_messages(
self,
messages: list[dict[str, Any]],
) -> ProviderConversationState:
"""Return a state copy with an isolated pending-message list."""
return ProviderConversationState(
kind=self.kind,
provider=self.provider,
model=self.model,
version=self.version,
payload=self.payload,
pending_messages=deepcopy(messages),
)
def to_private_record(self) -> dict[str, Any]:
"""Serialize for the private session sidecar, never for public history."""
return {
"kind": self.kind,
"provider": self.provider,
"model": self.model,
"version": self.version,
"payload": deepcopy(self.payload),
"pending_messages": deepcopy(self.pending_messages),
}
@classmethod
def from_private_record(
cls,
value: object,
) -> ProviderConversationState | None:
"""Validate and deserialize a private session-sidecar value."""
if not isinstance(value, dict):
return None
data = cast(dict[str, Any], value)
kind = data.get("kind")
provider = data.get("provider")
model = data.get("model")
version = data.get("version")
payload = data.get("payload")
pending = data.get("pending_messages", [])
if (
not isinstance(kind, str)
or not kind
or not isinstance(provider, str)
or not provider
or not isinstance(model, str)
or not model
or isinstance(version, bool)
or not isinstance(version, int)
or not isinstance(payload, dict)
or not isinstance(pending, list)
or any(
not isinstance(message, dict)
for message in cast(list[object], pending)
)
):
return None
return cls(
kind=kind,
provider=provider,
model=model,
version=version,
payload=deepcopy(cast(dict[str, Any], payload)),
pending_messages=deepcopy(cast(list[dict[str, Any]], pending)),
)
@dataclass(frozen=True)
class ProviderCallContext:
"""Optional provider-owned continuation data for one model request.
The regular ``chat`` contract stays provider-agnostic. Responses-capable
providers consume this context through the opt-in ``chat_with_context``
hooks, while every other provider inherits the context-free delegation.
``session_id`` gives providers a stable conversation-scoped routing key
without exposing that identity in the public message transcript.
"""
conversation_state: ProviderConversationState | None = field(default=None, repr=False)
context_window_tokens: int | None = None
session_id: str | None = field(default=None, repr=False)
@dataclass(frozen=True, slots=True)
class LLMUsage:
"""Canonical token usage reported by, or estimated for, one or more LLM calls.
``input_tokens`` is the logical input total and therefore includes cache reads
and writes. ``None`` cache counts mean the wire protocol did not report that
metric, while zero means it explicitly reported no cache activity.
``total_tokens`` preserves a provider-reported total when it exceeds the
visible input plus output (for example, hidden reasoning or tool usage). It
must be at least ``input_tokens + output_tokens``. The reported and estimated
totals partition it exactly, including after multi-call aggregation.
"""
input_tokens: int
output_tokens: int
total_tokens: int
cache_read_tokens: int | None = None
cache_write_tokens: int | None = None
reported_tokens: int = 0
estimated_tokens: int = 0
generation_ms: int = 0
measured_output_tokens: int = 0
ttft_ms: int = 0
timed_requests: int = 0
context_tokens: int | None = None
request_count: int = 0
def __post_init__(self) -> None:
token_fields = {
"input_tokens": self.input_tokens,
"output_tokens": self.output_tokens,
"total_tokens": self.total_tokens,
"reported_tokens": self.reported_tokens,
"estimated_tokens": self.estimated_tokens,
"generation_ms": self.generation_ms,
"measured_output_tokens": self.measured_output_tokens,
"ttft_ms": self.ttft_ms,
"timed_requests": self.timed_requests,
"request_count": self.request_count,
}
for name, value in token_fields.items():
runtime_value = cast(object, value)
if (
not isinstance(runtime_value, int)
or isinstance(runtime_value, bool)
or runtime_value < 0
):
raise ValueError(f"{name} must be a non-negative integer")
for name, value in (
("cache_read_tokens", self.cache_read_tokens),
("cache_write_tokens", self.cache_write_tokens),
("context_tokens", self.context_tokens),
):
runtime_value = cast(object, value)
if runtime_value is not None and (
not isinstance(runtime_value, int)
or isinstance(runtime_value, bool)
or runtime_value < 0
):
raise ValueError(f"{name} must be None or a non-negative integer")
visible_total = self.input_tokens + self.output_tokens
if self.total_tokens < visible_total:
raise ValueError("total_tokens must be at least input_tokens + output_tokens")
if self.reported_tokens + self.estimated_tokens != self.total_tokens:
raise ValueError("reported_tokens + estimated_tokens must equal total_tokens")
cache_total = (self.cache_read_tokens or 0) + (self.cache_write_tokens or 0)
if cache_total > self.input_tokens:
raise ValueError("cache token counts cannot exceed logical input_tokens")
@classmethod
def reported(
cls,
*,
input_tokens: int,
output_tokens: int,
total_tokens: int | None = None,
cache_read_tokens: int | None = None,
cache_write_tokens: int | None = None,
) -> LLMUsage:
"""Build usage normalized from a provider response."""
visible_total = input_tokens + output_tokens
normalized_total = (
visible_total if total_tokens is None else max(visible_total, total_tokens)
)
return cls(
input_tokens=input_tokens,
output_tokens=output_tokens,
total_tokens=normalized_total,
cache_read_tokens=cache_read_tokens,
cache_write_tokens=cache_write_tokens,
reported_tokens=normalized_total,
context_tokens=input_tokens,
request_count=1,
)
@classmethod
def estimated(cls, *, input_tokens: int, output_tokens: int) -> LLMUsage:
"""Build usage estimated locally because the provider omitted it."""
return cls(
input_tokens=input_tokens,
output_tokens=output_tokens,
total_tokens=input_tokens + output_tokens,
estimated_tokens=input_tokens + output_tokens,
context_tokens=input_tokens,
request_count=1,
)
@classmethod
def empty_request(cls) -> LLMUsage:
"""Represent a completed model request with no measurable token usage."""
return cls(
input_tokens=0,
output_tokens=0,
total_tokens=0,
request_count=1,
)
@property
def source(self) -> Literal["reported", "estimated", "mixed"]:
if self.estimated_tokens == 0:
return "reported"
if self.reported_tokens == 0:
return "estimated"
return "mixed"
def with_timing(
self,
*,
generation_ms: int | None,
ttft_ms: int | None,
) -> LLMUsage:
"""Attach locally measured streaming telemetry to this usage value."""
return LLMUsage(
input_tokens=self.input_tokens,
output_tokens=self.output_tokens,
total_tokens=self.total_tokens,
cache_read_tokens=self.cache_read_tokens,
cache_write_tokens=self.cache_write_tokens,
reported_tokens=self.reported_tokens,
estimated_tokens=self.estimated_tokens,
generation_ms=max(0, generation_ms or 0),
measured_output_tokens=self.output_tokens if generation_ms is not None else 0,
ttft_ms=max(0, ttft_ms or 0),
timed_requests=1 if ttft_ms is not None else 0,
context_tokens=self.context_tokens,
request_count=self.request_count,
)
def __add__(self, other: LLMUsage) -> LLMUsage:
"""Aggregate calls without turning partially reported cache data into a count."""
def _sum_cache(left: int | None, right: int | None) -> int | None:
return left + right if left is not None and right is not None else None
return LLMUsage(
input_tokens=self.input_tokens + other.input_tokens,
output_tokens=self.output_tokens + other.output_tokens,
total_tokens=self.total_tokens + other.total_tokens,
cache_read_tokens=_sum_cache(self.cache_read_tokens, other.cache_read_tokens),
cache_write_tokens=_sum_cache(self.cache_write_tokens, other.cache_write_tokens),
reported_tokens=self.reported_tokens + other.reported_tokens,
estimated_tokens=self.estimated_tokens + other.estimated_tokens,
generation_ms=self.generation_ms + other.generation_ms,
measured_output_tokens=(
self.measured_output_tokens + other.measured_output_tokens
),
ttft_ms=self.ttft_ms + other.ttft_ms,
timed_requests=self.timed_requests + other.timed_requests,
context_tokens=(
other.context_tokens
if other.context_tokens is not None
else self.context_tokens
),
request_count=self.request_count + other.request_count,
)
def to_dict(self) -> dict[str, int | str | None]:
"""Serialize the canonical contract at JSON/persistence boundaries."""
return {
"input_tokens": self.input_tokens,
"output_tokens": self.output_tokens,
"total_tokens": self.total_tokens,
"cache_read_tokens": self.cache_read_tokens,
"cache_write_tokens": self.cache_write_tokens,
"reported_tokens": self.reported_tokens,
"estimated_tokens": self.estimated_tokens,
"source": self.source,
"generation_ms": self.generation_ms,
"measured_output_tokens": self.measured_output_tokens,
"ttft_ms": self.ttft_ms,
"timed_requests": self.timed_requests,
"context_tokens": self.context_tokens,
"request_count": self.request_count,
}
def to_turn_dict(self) -> dict[str, int]:
"""Project canonical usage into the compact WebUI/TUI per-turn shape."""
result: dict[str, int] = {
"prompt_tokens": self.input_tokens,
"completion_tokens": self.output_tokens,
"total_tokens": self.total_tokens,
"request_count": self.request_count,
"estimated_tokens": self.estimated_tokens,
}
if self.context_tokens is not None:
result["context_tokens"] = self.context_tokens
if self.cache_read_tokens is not None:
result["cached_tokens"] = self.cache_read_tokens
if self.cache_write_tokens is not None:
result["cache_write_tokens"] = self.cache_write_tokens
if self.generation_ms > 0 and self.measured_output_tokens > 0:
result["generation_ms"] = self.generation_ms
result["measured_completion_tokens"] = self.measured_output_tokens
if self.timed_requests > 0:
result["ttft_ms"] = self.ttft_ms
result["timed_requests"] = self.timed_requests
return result
@classmethod
def from_dict(cls, value: object) -> LLMUsage | None:
"""Validate the exact first-party serialized contract."""
if not isinstance(value, dict):
return None
data = cast(dict[object, object], value)
integer_fields = (
"input_tokens",
"output_tokens",
"reported_tokens",
"estimated_tokens",
"generation_ms",
"measured_output_tokens",
"ttft_ms",
"timed_requests",
"request_count",
)
serialized_fields = {
*integer_fields,
"total_tokens",
"cache_read_tokens",
"cache_write_tokens",
"context_tokens",
"source",
}
if set(data) != serialized_fields:
return None
if any(
not isinstance(item := data.get(name), int) or isinstance(item, bool)
for name in integer_fields
):
return None
cache_read = data.get("cache_read_tokens")
cache_write = data.get("cache_write_tokens")
context_tokens = data.get("context_tokens")
total = data.get("total_tokens")
source = data.get("source")
if any(
item is not None and (not isinstance(item, int) or isinstance(item, bool))
for item in (cache_read, cache_write, context_tokens)
) or not isinstance(total, int) or isinstance(total, bool):
return None
try:
usage = cls(
input_tokens=cast(int, data["input_tokens"]),
output_tokens=cast(int, data["output_tokens"]),
total_tokens=total,
cache_read_tokens=cast(int | None, cache_read),
cache_write_tokens=cast(int | None, cache_write),
reported_tokens=cast(int, data["reported_tokens"]),
estimated_tokens=cast(int, data["estimated_tokens"]),
generation_ms=cast(int, data["generation_ms"]),
measured_output_tokens=cast(int, data["measured_output_tokens"]),
ttft_ms=cast(int, data["ttft_ms"]),
timed_requests=cast(int, data["timed_requests"]),
context_tokens=cast(int | None, context_tokens),
request_count=cast(int, data["request_count"]),
)
except (KeyError, ValueError):
return None
if source != usage.source:
return None
return usage
@dataclass
class LLMResponse:
"""Response from an LLM provider."""
content: str | None
tool_calls: list[ToolCallRequest] = field(default_factory=list)
finish_reason: str = "stop"
usage: LLMUsage | None = None
# Locally measured streaming telemetry. ``generation_ms`` excludes time to
# first token and provider retry gaps; ``ttft_ms`` measures the first
# streamed reasoning/content delta from request start. They stay separate
# from provider usage because providers do not report these consistently.
generation_ms: int | None = None
ttft_ms: int | None = None
retry_after: float | None = None # Provider supplied retry wait in seconds.
reasoning_content: str | None = None # Kimi, DeepSeek-R1, MiMo etc.
thinking_blocks: list[dict[str, Any]] | None = None # Anthropic extended thinking
provider_state: ProviderConversationState | None = field(default=None, repr=False)
# Routing wrappers may preserve or discard an incoming provider-owned
# continuation independently of the final fallback error's retry policy.
preserve_provider_state_on_error: bool | None = field(default=None, repr=False)
# Structured error metadata used by retry policy when finish_reason == "error".
error_status_code: int | None = None
error_kind: str | None = None # e.g. "timeout", "connection"
error_type: str | None = None # Provider/type semantic, e.g. insufficient_quota.
error_code: str | None = None # Provider/code semantic, e.g. rate_limit_exceeded.
error_retry_after_s: float | None = None
error_should_retry: bool | None = None
@property
def has_tool_calls(self) -> bool:
"""Check if response contains tool calls."""
return len(self.tool_calls) > 0
@property
def should_execute_tools(self) -> bool:
"""Tools execute only when has_tool_calls AND finish_reason is a tool-capable stop.
Blocks gateway-injected calls under ``refusal`` / ``content_filter`` / ``error`` (#3220)."""
if not self.has_tool_calls:
return False
return self.finish_reason in ("tool_calls", "function_call", "stop")
@dataclass(frozen=True)
class GenerationSettings:
"""Default generation settings."""
temperature: float = 0.7
max_tokens: int = 4096
reasoning_effort: str | None = None
_SYNTHETIC_USER_CONTENT = "(conversation continued)"
class LLMProvider(ABC):
"""Base class for LLM providers."""
supports_progress_deltas = False
_CHAT_RETRY_DELAYS = (1, 2, 4)
_PERSISTENT_MAX_DELAY = 60
_PERSISTENT_IDENTICAL_ERROR_LIMIT = 10
_RETRY_HEARTBEAT_CHUNK = 30
_TRANSIENT_ERROR_MARKERS = (
"429",
"rate limit",
"500",
"502",
"503",
"504",
"overloaded",
"timeout",
"timed out",
"connection",
"server error",
"server_error",
"temporarily unavailable",
"速率限制",
"访问量过大",
)
_RETRYABLE_STATUS_CODES = frozenset({408, 409, 429})
_TRANSIENT_ERROR_KINDS = frozenset({"timeout", "connection"})
_NON_RETRYABLE_429_ERROR_TOKENS = frozenset({
"insufficient_quota",
"quota_exceeded",
"quota_exhausted",
"billing_hard_limit_reached",
"insufficient_balance",
"credit_balance_too_low",
"billing_not_active",
"payment_required",
})
_RETRYABLE_429_ERROR_TOKENS = frozenset({
"rate_limit_exceeded",
"rate_limit_error",
"too_many_requests",
"request_limit_exceeded",
"requests_limit_exceeded",
"overloaded_error",
})
_NON_RETRYABLE_429_TEXT_MARKERS = (
"insufficient_quota",
"insufficient quota",
"quota exceeded",
"quota exhausted",
"billing hard limit",
"billing_hard_limit_reached",
"billing not active",
"insufficient balance",
"insufficient_balance",
"credit balance too low",
"payment required",
"out of credits",
"out of quota",
"exceeded your current quota",
)
_RETRYABLE_429_TEXT_MARKERS = (
"rate limit",
"rate_limit",
"too many requests",
"retry after",
"try again in",
"temporarily unavailable",
"overloaded",
"concurrency limit",
"速率限制",
)
_SENTINEL = object()
def __init__(
self,
api_key: str | None = None,
api_base: str | None = None,
*,
provider_name: str,
):
runtime_provider_name = cast(object, provider_name)
if not isinstance(runtime_provider_name, str) or not runtime_provider_name.strip():
raise ValueError("provider_name must be a non-empty configured identity")
self.api_key = api_key
self.api_base = api_base
self.provider_name = provider_name
self.generation: GenerationSettings = GenerationSettings()
self._llm_call_observer: LLMCallObserver | None = None
def set_llm_call_observer(self, observer: LLMCallObserver | None) -> None:
"""Attach a fail-open observer for each physical retry-managed call."""
self._llm_call_observer = observer
def _usage_for_call(
self,
response: LLMResponse,
kwargs: dict[str, Any],
) -> LLMUsage | None:
usage = response.usage
if usage is None or usage.total_tokens == 0:
if response.finish_reason in {"error", "cancelled"}:
return None
messages = kwargs.get("messages")
if not isinstance(messages, list):
return usage
tools_value = kwargs.get("tools")
tools = cast(list[dict[str, Any]], tools_value) if isinstance(tools_value, list) else None
model_value = kwargs.get("model")
model = model_value if isinstance(model_value, str) else self.get_default_model()
try:
from nanobot.utils.helpers import (
build_assistant_message,
estimate_message_tokens,
estimate_prompt_tokens_chain,
)
input_tokens, _ = estimate_prompt_tokens_chain(
self,
model,
cast(list[dict[str, Any]], messages),
tools,
)
assistant_message = build_assistant_message(
response.content or "",
tool_calls=[call.to_openai_tool_call() for call in response.tool_calls],
reasoning_content=response.reasoning_content,
thinking_blocks=response.thinking_blocks,
)
usage = LLMUsage.estimated(
input_tokens=max(0, input_tokens),
output_tokens=max(0, estimate_message_tokens(assistant_message)),
)
except Exception:
logger.exception("failed to estimate usage for {}", self.provider_name)
return usage
return usage.with_timing(
generation_ms=response.generation_ms,
ttft_ms=response.ttft_ms,
)
def _observe_llm_call(
self,
response: LLMResponse,
kwargs: dict[str, Any],
*,
started_at_ms: int,
started_at_ns: int,
stream: bool,
) -> LLMResponse:
observer = self._llm_call_observer
if observer is None:
return response
usage = self._usage_for_call(response, kwargs)
if usage is not None:
response.usage = usage
model_value = kwargs.get("model")
model = model_value if isinstance(model_value, str) and model_value else self.get_default_model()
try:
from nanobot.llm_usage.context import current_llm_usage_source
from nanobot.llm_usage.models import LLMCallRecord
observer(LLMCallRecord(
started_at_ms=started_at_ms,
duration_ms=max(0, (time.monotonic_ns() - started_at_ns) // 1_000_000),
provider=self.provider_name,
model=model,
source=current_llm_usage_source(),
stream=stream,
finish_reason=response.finish_reason,
usage=usage,
error_status_code=response.error_status_code,
error_kind=response.error_kind,
))
except Exception:
logger.exception("LLM call observer failed for {}", self.provider_name)
return response
def can_resume_conversation_state(
self,
state: ProviderConversationState,
model: str | None = None,
) -> bool:
"""Whether this provider can safely consume an opaque saved state."""
return False
def supports_native_compaction(self, model: str | None = None) -> bool:
"""Whether requests may include provider-native context compaction."""
return False
@staticmethod
def _sanitize_empty_content(messages: list[dict[str, Any]]) -> list[dict[str, Any]]:
"""Sanitize message content: fix empty blocks, strip internal _meta fields.
Also strips unpaired UTF-16 surrogate code points from every string leaf
as a defense-in-depth pass before the payload leaves the process. Lone
surrogates (e.g. leaking from a Windows console, prompt_toolkit history,
or a truncated JSON round-trip) otherwise cause ``UnicodeEncodeError:
'utf-8' codec can't encode characters ... surrogates not allowed`` when
the HTTP client serializes the request body.
"""
result: list[dict[str, Any]] = []
for raw_msg in messages:
msg = {key: value for key, value in raw_msg.items() if key != "_meta"}
content = msg.get("content")
if isinstance(content, str) and not content:
clean = dict(msg)
clean["content"] = None if (msg.get("role") == "assistant" and msg.get("tool_calls")) else "(empty)"
result.append(clean)
continue
if isinstance(content, list):
new_items: list[Any] = []
changed = False
for raw_item in cast(list[object], content):
item = cast(dict[str, Any], raw_item) if isinstance(raw_item, dict) else None
if (
item is not None
and item.get("type") in ("text", "input_text", "output_text")
and not item.get("text")
):
changed = True
continue
if item is not None and "_meta" in item:
new_items.append({k: v for k, v in item.items() if k != "_meta"})
changed = True
else:
new_items.append(raw_item)
if changed:
clean = dict(msg)
if new_items:
clean["content"] = new_items
elif msg.get("role") == "assistant" and msg.get("tool_calls"):
clean["content"] = None
else:
clean["content"] = "(empty)"
result.append(clean)
continue
if isinstance(content, dict):
clean = dict(msg)
clean["content"] = [content]
result.append(clean)
continue
result.append(msg)
# Defense-in-depth: scrub lone UTF-16 surrogates from every string leaf.
# This is idempotent and no-op when messages are already clean.
sanitized = sanitize_surrogates_deep(result)
return cast(list[dict[str, Any]], sanitized) if isinstance(sanitized, list) else result
@staticmethod
def _tool_name(tool: dict[str, Any]) -> str:
"""Extract tool name from either OpenAI or Anthropic-style tool schemas."""
name = tool.get("name")
if isinstance(name, str):
return name
fn = tool.get("function")
fn_object = cast(dict[str, Any], fn) if isinstance(fn, dict) else None
if fn_object is not None:
fname = fn_object.get("name")
if isinstance(fname, str):
return fname
return ""
@classmethod
def _tool_cache_marker_indices(cls, tools: list[dict[str, Any]]) -> list[int]:
"""Return cache marker indices: builtin/MCP boundary and tail index."""
if not tools:
return []
tail_idx = len(tools) - 1
last_builtin_idx: int | None = None
for i in range(tail_idx, -1, -1):
if not cls._tool_name(tools[i]).startswith("mcp_"):
last_builtin_idx = i
break
ordered_unique: list[int] = []
for idx in (last_builtin_idx, tail_idx):
if idx is not None and idx not in ordered_unique:
ordered_unique.append(idx)
return ordered_unique
@staticmethod
def _sanitize_request_messages(
messages: list[dict[str, Any]],
allowed_keys: frozenset[str],
) -> list[dict[str, Any]]:
"""Keep only provider-safe message keys and normalize assistant content."""
sanitized: list[dict[str, Any]] = []
for msg in messages:
clean = {k: v for k, v in msg.items() if k in allowed_keys}
if clean.get("role") == "assistant" and "content" not in clean:
clean["content"] = None
sanitized.append(clean)
return sanitized
@abstractmethod
async def chat(
self,
messages: list[dict[str, Any]],
tools: list[dict[str, Any]] | None = None,
model: str | None = None,
max_tokens: int = 4096,
temperature: float = 0.7,
reasoning_effort: str | None = None,
tool_choice: str | dict[str, Any] | None = None,
) -> LLMResponse:
"""
Send a chat completion request.
Args:
messages: List of message dicts with 'role' and 'content'.
tools: Optional list of tool definitions.
model: Model identifier (provider-specific).
max_tokens: Maximum tokens in response.
temperature: Sampling temperature.
tool_choice: Tool selection strategy ("auto", "required", or specific tool dict).
Returns:
LLMResponse with content and/or tool calls.
"""
pass
@classmethod
def _is_transient_error(cls, content: str | None) -> bool:
err = (content or "").lower()
return any(marker in err for marker in cls._TRANSIENT_ERROR_MARKERS)
@classmethod
def is_transient_response(cls, response: LLMResponse) -> bool:
"""Prefer structured error metadata, fallback to text markers for legacy providers."""
if response.error_should_retry is not None:
return bool(response.error_should_retry)
if response.error_status_code is not None:
status = int(response.error_status_code)
if status == 429:
return cls._is_retryable_429_response(response)
if status in cls._RETRYABLE_STATUS_CODES or status >= 500:
return True
kind = (response.error_kind or "").strip().lower()
if kind in cls._TRANSIENT_ERROR_KINDS:
return True
return cls._is_transient_error(response.content)
@classmethod
def is_arrearage_response(cls, response: LLMResponse) -> bool:
"""Detect API-key arrearage / quota / billing errors that won't clear on retry.
These surface as HTTP 402 or as billing semantic tokens (e.g.
``insufficient_quota``, ``payment_required``); reuses the same token and
text markers the 429 retry policy treats as non-retryable.
"""
if response.error_status_code is not None and int(response.error_status_code) == 402:
return True
type_token = cls._normalize_error_token(response.error_type)
code_token = cls._normalize_error_token(response.error_code)
if any(
token in cls._NON_RETRYABLE_429_ERROR_TOKENS
for token in (type_token, code_token)
if token is not None
):
return True
content = (response.content or "").lower()
return any(marker in content for marker in cls._NON_RETRYABLE_429_TEXT_MARKERS)
@staticmethod
def _normalize_error_token(value: Any) -> str | None:
if value is None:
return None
token = str(value).strip().lower()
return token or None
@classmethod
def _extract_error_type_code(cls, payload: Any) -> tuple[str | None, str | None]:
data: dict[str, Any] | None = None
if isinstance(payload, dict):
data = cast(dict[str, Any], payload)
elif isinstance(payload, str):
text = payload.strip()
if text:
try:
parsed = json.loads(text)
except Exception:
parsed = None
if isinstance(parsed, dict):
data = cast(dict[str, Any], parsed)
if data is None:
return None, None
error_obj = data.get("error")
type_value = data.get("type")
code_value = data.get("code")
error_object = cast(dict[str, Any], error_obj) if isinstance(error_obj, dict) else None
if error_object is not None:
type_value = error_object.get("type") or type_value
code_value = error_object.get("code") or code_value
return cls._normalize_error_token(type_value), cls._normalize_error_token(code_value)
@classmethod
def _is_retryable_429_response(cls, response: LLMResponse) -> bool:
type_token = cls._normalize_error_token(response.error_type)
code_token = cls._normalize_error_token(response.error_code)
semantic_tokens = {
token for token in (type_token, code_token)
if token is not None
}
if any(token in cls._NON_RETRYABLE_429_ERROR_TOKENS for token in semantic_tokens):
return False
content = (response.content or "").lower()
if any(marker in content for marker in cls._NON_RETRYABLE_429_TEXT_MARKERS):
return False
if any(token in cls._RETRYABLE_429_ERROR_TOKENS for token in semantic_tokens):
return True
if any(marker in content for marker in cls._RETRYABLE_429_TEXT_MARKERS):
return True
# Unknown 429 defaults to WAIT+retry.
return True
@staticmethod
def _enforce_role_alternation(messages: list[dict[str, Any]]) -> list[dict[str, Any]]:
"""Merge consecutive same-role messages and drop trailing assistant messages.
Some providers (OpenAI-compat, Azure, vLLM, Ollama, etc.) reject requests
where the last message is 'assistant' (prefill not supported) or two
consecutive non-system messages share the same role.
"""
if not messages:
return messages
merged: list[dict[str, Any]] = []
for msg in messages:
role = msg.get("role")
if (
merged
and role != "system"
and role not in ("tool",)
and merged[-1].get("role") == role
and role in ("user", "assistant")
):
prev = merged[-1]
if role == "assistant":
prev_has_tools = bool(prev.get("tool_calls"))
curr_has_tools = bool(msg.get("tool_calls"))
if curr_has_tools:
merged[-1] = dict(msg)
continue
if prev_has_tools:
continue
prev_content = prev.get("content") or ""
curr_content = msg.get("content") or ""
if isinstance(prev_content, str) and isinstance(curr_content, str):
prev["content"] = (prev_content + "\n\n" + curr_content).strip()
else:
merged[-1] = dict(msg)
else:
merged.append(dict(msg))
last_popped = None
while merged and merged[-1].get("role") == "assistant":
last_popped = merged.pop()
# If removing trailing assistant messages left only system messages,
# the request would be invalid for most providers (e.g. Zhipu/GLM
# error 1214). Recover by converting the last popped assistant
# message to a user message so the LLM can still see the content.
if (
merged
and last_popped is not None
and not any(m.get("role") in ("user", "tool") for m in merged)
):
recovered = dict(last_popped)
recovered["role"] = "user"
merged.append(recovered)
# Safety net: ensure the first non-system message is not a bare
# ``assistant`` message. Providers like GLM reject system→assistant
# with error 1214. This can happen when upstream truncation (e.g.
# _snip_history) drops the only user message. Insert a synthetic
# user message to keep the sequence valid.
for i, msg in enumerate(merged):
if msg.get("role") != "system":
if msg.get("role") == "assistant" and not msg.get("tool_calls"):
merged.insert(i, {"role": "user", "content": _SYNTHETIC_USER_CONTENT})
break
return merged
@staticmethod
def _strip_image_content(messages: list[dict[str, Any]]) -> list[dict[str, Any]] | None:
"""Replace image_url blocks with text placeholder. Returns None if no images found."""
found = False
result: list[dict[str, Any]] = []
for msg in messages:
content = msg.get("content")
if isinstance(content, list):
new_content: list[Any] = []
for raw_block in cast(list[object], content):
block = cast(dict[str, Any], raw_block) if isinstance(raw_block, dict) else None
if block is not None and block.get("type") == "image_url":
placeholder = (
"[Image not delivered to model — "
"do not describe or reference it]"
)
new_content.append({"type": "text", "text": placeholder})
found = True
else:
new_content.append(raw_block)
result.append({**msg, "content": new_content})
else:
result.append(msg)
return result if found else None
@staticmethod
def _contains_image_content(value: object) -> bool:
"""Return whether a JSON-like provider payload contains an input image."""
if isinstance(value, dict):
mapping = cast(dict[str, object], value)
if mapping.get("type") in {"image_url", "input_image"}:
return True
return any(LLMProvider._contains_image_content(item) for item in mapping.values())
if isinstance(value, list):
return any(
LLMProvider._contains_image_content(item)
for item in cast(list[object], value)
)
return False
@staticmethod
def _strip_image_content_inplace(messages: list[dict[str, Any]]) -> bool:
"""Replace image_url blocks with text placeholder *in-place*.
Mutates the content lists of the original message dicts so that
callers holding references to those dicts also see the stripped
version.
"""
found = False
for msg in messages:
content = msg.get("content")
if isinstance(content, list):
for i, raw_block in enumerate(cast(list[object], content)):
block = cast(dict[str, Any], raw_block) if isinstance(raw_block, dict) else None
if block is not None and block.get("type") == "image_url":
placeholder = (
"[Image not delivered to model — "
"do not describe or reference it]"
)
content[i] = {"type": "text", "text": placeholder}
found = True
return found
async def _safe_chat(self, **kwargs: Any) -> LLMResponse:
"""Call chat() and convert unexpected exceptions to error responses."""
started_at_ms = time.time_ns() // 1_000_000
started_at_ns = time.monotonic_ns()
try:
provider_context = kwargs.pop("provider_context", None)
if isinstance(provider_context, ProviderCallContext):
response = await self.chat_with_context(
provider_context=provider_context,
**kwargs,
)
else:
response = await self.chat(**kwargs)
except asyncio.CancelledError:
self._observe_llm_call(
LLMResponse(
content=None,
finish_reason="cancelled",
error_kind="cancelled",
),
kwargs,
started_at_ms=started_at_ms,
started_at_ns=started_at_ns,
stream=False,
)
raise
except Exception as exc:
response = LLMResponse(content=f"Error calling LLM: {exc}", finish_reason="error")
return self._observe_llm_call(
response,
kwargs,
started_at_ms=started_at_ms,
started_at_ns=started_at_ns,
stream=False,
)
async def chat_stream(
self,
messages: list[dict[str, Any]],
tools: list[dict[str, Any]] | None = None,
model: str | None = None,
max_tokens: int = 4096,
temperature: float = 0.7,
reasoning_effort: str | None = None,
tool_choice: str | dict[str, Any] | None = None,
on_content_delta: Callable[[str], Awaitable[None]] | None = None,
on_thinking_delta: Callable[[str], Awaitable[None]] | None = None,
on_tool_call_delta: Callable[[dict[str, Any]], Awaitable[None]] | None = None,
) -> LLMResponse:
"""Stream a chat completion, calling *on_content_delta* for each text chunk.
*on_thinking_delta* is reserved for providers that expose incremental
thinking/reasoning on the wire; the default fallback invokes neither
callback for native deltas (only the optional single *on_content_delta*
after :meth:`chat`).
Returns the same ``LLMResponse`` as :meth:`chat`. The default
implementation falls back to a non-streaming call and delivers the
full content as a single delta. Providers that support native
streaming should override this method.
"""
_ = on_thinking_delta, on_tool_call_delta
response = await self.chat(
messages=messages,
tools=tools,
model=model,
max_tokens=max_tokens,
temperature=temperature,
reasoning_effort=reasoning_effort,
tool_choice=tool_choice,
)
if on_content_delta and response.content:
await on_content_delta(response.content)
return response
async def chat_with_context(
self,
*,
provider_context: ProviderCallContext,
**kwargs: Any,
) -> LLMResponse:
"""Opt-in continuation hook; ordinary providers delegate to ``chat``."""
_ = provider_context
return await self.chat(**kwargs)
async def chat_stream_with_context(
self,
*,
provider_context: ProviderCallContext,
**kwargs: Any,
) -> LLMResponse:
"""Streaming continuation hook with a context-free default."""
_ = provider_context
return await self.chat_stream(**kwargs)
async def _safe_chat_stream(self, **kwargs: Any) -> LLMResponse:
"""Call chat_stream() and convert unexpected exceptions to error responses."""
started_at_ms = time.time_ns() // 1_000_000
started_at_ns = time.monotonic_ns()
first_output_at_ns: int | None = None
def _mark_output(delta: str) -> None:
nonlocal first_output_at_ns
if delta and first_output_at_ns is None:
first_output_at_ns = time.monotonic_ns()
if self._llm_call_observer is not None:
content_callback = kwargs.get("on_content_delta")
if callable(content_callback):
typed_content_callback = cast(
Callable[[str], Awaitable[None]],
content_callback,
)
async def _timed_content_delta(delta: str) -> None:
_mark_output(delta)
await typed_content_callback(delta)
kwargs["on_content_delta"] = _timed_content_delta
thinking_callback = kwargs.get("on_thinking_delta")
if callable(thinking_callback):
typed_thinking_callback = cast(
Callable[[str], Awaitable[None]],
thinking_callback,
)
async def _timed_thinking_delta(delta: str) -> None:
_mark_output(delta)
await typed_thinking_callback(delta)
kwargs["on_thinking_delta"] = _timed_thinking_delta
def _attach_stream_timing(response: LLMResponse) -> LLMResponse:
if first_output_at_ns is None:
return response
finished_at_ns = time.monotonic_ns()
if response.ttft_ms is None:
response.ttft_ms = max(0, round((first_output_at_ns - started_at_ns) / 1_000_000))
if response.generation_ms is None:
response.generation_ms = max(
1,
round((finished_at_ns - first_output_at_ns) / 1_000_000),
)
return response
try:
provider_context = kwargs.pop("provider_context", None)
if isinstance(provider_context, ProviderCallContext):
response = await self.chat_stream_with_context(
provider_context=provider_context,
**kwargs,
)
else:
response = await self.chat_stream(**kwargs)
except asyncio.CancelledError:
self._observe_llm_call(
LLMResponse(
content=None,
finish_reason="cancelled",
error_kind="cancelled",
),
kwargs,
started_at_ms=started_at_ms,
started_at_ns=started_at_ns,
stream=True,
)
raise
except Exception as exc:
response = LLMResponse(content=f"Error calling LLM: {exc}", finish_reason="error")
return self._observe_llm_call(
_attach_stream_timing(response),
kwargs,
started_at_ms=started_at_ms,
started_at_ns=started_at_ns,
stream=True,
)
async def chat_stream_with_retry(
self,
messages: list[dict[str, Any]],
tools: list[dict[str, Any]] | None = None,
model: str | None = None,
max_tokens: object = _SENTINEL,
temperature: object = _SENTINEL,
reasoning_effort: object = _SENTINEL,
tool_choice: str | dict[str, Any] | None = None,
on_content_delta: Callable[[str], Awaitable[None]] | None = None,
on_thinking_delta: Callable[[str], Awaitable[None]] | None = None,
on_tool_call_delta: Callable[[dict[str, Any]], Awaitable[None]] | None = None,
on_stream_recover: Callable[[], Awaitable[None]] | None = None,
retry_mode: str = "standard",
on_retry_wait: RetryEventCallback | None = None,
provider_context: ProviderCallContext | None = None,
on_retry_exhausted: RetryEventCallback | None = None,
) -> LLMResponse:
"""Call chat_stream() with retry on transient provider failures."""
if max_tokens is self._SENTINEL or max_tokens is None:
max_tokens = self.generation.max_tokens
if temperature is self._SENTINEL or temperature is None:
temperature = self.generation.temperature
if reasoning_effort is self._SENTINEL:
reasoning_effort = self.generation.reasoning_effort
has_streamed_content = False
async def _tracking_delta(text: str) -> None:
nonlocal has_streamed_content
if text:
has_streamed_content = True
if on_content_delta:
await on_content_delta(text)
async def _recover_stream() -> None:
nonlocal has_streamed_content
if on_stream_recover:
await on_stream_recover()
has_streamed_content = False
kw: dict[str, Any] = dict(
messages=messages, tools=tools, model=model,
max_tokens=max_tokens, temperature=temperature,
reasoning_effort=reasoning_effort, tool_choice=tool_choice,
on_content_delta=_tracking_delta if on_content_delta is not None else None,
on_thinking_delta=on_thinking_delta,
on_tool_call_delta=on_tool_call_delta,
)
if provider_context is not None:
kw["provider_context"] = provider_context
if on_stream_recover and getattr(self, "supports_stream_recover_callback", False):
kw["on_stream_recover"] = _recover_stream
return await self._run_chat_with_retry(
kw,
messages,
stream=True,
retry_mode=retry_mode,
on_retry_wait=on_retry_wait,
on_retry_exhausted=on_retry_exhausted or on_retry_wait,
should_retry_guard=lambda: not has_streamed_content,
on_stream_recover=_recover_stream if on_stream_recover else None,
)
async def chat_with_retry(
self,
messages: list[dict[str, Any]],
tools: list[dict[str, Any]] | None = None,
model: str | None = None,
max_tokens: object = _SENTINEL,
temperature: object = _SENTINEL,
reasoning_effort: object = _SENTINEL,
tool_choice: str | dict[str, Any] | None = None,
retry_mode: str = "standard",
on_retry_wait: RetryEventCallback | None = None,
provider_context: ProviderCallContext | None = None,
on_retry_exhausted: RetryEventCallback | None = None,
) -> LLMResponse:
"""Call chat() with retry on transient provider failures.
Parameters default to ``self.generation`` when not explicitly passed,
so callers no longer need to thread temperature / max_tokens /
reasoning_effort through every layer. Explicit ``None`` is also
normalized to the provider's generation defaults so that downstream
``_build_kwargs`` never sees ``None`` for ``max_tokens`` / ``temperature``
(which would crash ``max(1, max_tokens)``).
"""
if max_tokens is self._SENTINEL or max_tokens is None:
max_tokens = self.generation.max_tokens
if temperature is self._SENTINEL or temperature is None:
temperature = self.generation.temperature
if reasoning_effort is self._SENTINEL:
reasoning_effort = self.generation.reasoning_effort
kw: dict[str, Any] = dict(
messages=messages, tools=tools, model=model,
max_tokens=max_tokens, temperature=temperature,
reasoning_effort=reasoning_effort, tool_choice=tool_choice,
)
if provider_context is not None:
kw["provider_context"] = provider_context
return await self._run_chat_with_retry(
kw,
messages,
stream=False,
retry_mode=retry_mode,
on_retry_wait=on_retry_wait,
on_retry_exhausted=on_retry_exhausted or on_retry_wait,
)
async def _run_chat_with_retry(
self,
kw: dict[str, Any],
original_messages: list[dict[str, Any]],
*,
stream: bool,
retry_mode: str,
on_retry_wait: RetryEventCallback | None,
on_retry_exhausted: RetryEventCallback | None,
should_retry_guard: Callable[[], bool] | None = None,
on_stream_recover: Callable[[], Awaitable[None]] | None = None,
) -> LLMResponse:
"""Run one chat entry point through this provider's retry policy."""
call = self._safe_chat_stream if stream else self._safe_chat
return await self._run_with_retry(
call,
kw,
original_messages,
retry_mode=retry_mode,
on_retry_wait=on_retry_wait,
on_retry_exhausted=on_retry_exhausted,
should_retry_guard=should_retry_guard,
on_stream_recover=on_stream_recover,
)
@classmethod
def _extract_retry_after(cls, content: str | None) -> float | None:
text = (content or "").lower()
patterns = (
r"retry after\s+(\d+(?:\.\d+)?)\s*(ms|milliseconds|s|sec|secs|seconds|m|min|minutes)?",
r"try again in\s+(\d+(?:\.\d+)?)\s*(ms|milliseconds|s|sec|secs|seconds|m|min|minutes)",
r"wait\s+(\d+(?:\.\d+)?)\s*(ms|milliseconds|s|sec|secs|seconds|m|min|minutes)\s*before retry",
r"retry[_-]?after[\"'\s:=]+(\d+(?:\.\d+)?)",
)
for idx, pattern in enumerate(patterns):
match = re.search(pattern, text)
if not match:
continue
value = float(match.group(1))
unit = match.group(2) if idx < 3 else "s"
return cls._to_retry_seconds(value, unit)
return None
@classmethod
def _to_retry_seconds(cls, value: float, unit: str | None = None) -> float:
normalized_unit = (unit or "s").lower()
if normalized_unit in {"ms", "milliseconds"}:
return max(0.1, value / 1000.0)
if normalized_unit in {"m", "min", "minutes"}:
return max(0.1, value * 60.0)
return max(0.1, value)
@classmethod
def _extract_retry_after_from_headers(cls, headers: Any) -> float | None:
if not headers:
return None
def _header_value(name: str) -> Any:
if hasattr(headers, "get"):
value = headers.get(name) or headers.get(name.title())
if value is not None:
return value
if isinstance(headers, dict):
for key, value in cast(dict[object, Any], headers).items():
if isinstance(key, str) and key.lower() == name.lower():
return value
return None
with suppress(TypeError, ValueError):
retry_ms = _header_value("retry-after-ms")
if retry_ms is not None:
value = float(retry_ms) / 1000.0
if value > 0:
return value
retry_after = _header_value("retry-after")
if retry_after is None:
return None
retry_after_text = str(retry_after).strip()
if not retry_after_text:
return None
if re.fullmatch(r"\d+(?:\.\d+)?", retry_after_text):
return cls._to_retry_seconds(float(retry_after_text), "s")
try:
retry_at = parsedate_to_datetime(retry_after_text)
except Exception:
return None
if retry_at.tzinfo is None:
retry_at = retry_at.replace(tzinfo=timezone.utc)
remaining = (retry_at - datetime.now(retry_at.tzinfo)).total_seconds()
return max(0.1, remaining)
@classmethod
def _extract_retry_after_from_response(cls, response: LLMResponse) -> float | None:
if response.error_retry_after_s is not None and response.error_retry_after_s > 0:
return response.error_retry_after_s
if response.retry_after is not None and response.retry_after > 0:
return response.retry_after
return cls._extract_retry_after(response.content)
async def _sleep_with_heartbeat(
self,
delay: float,
*,
attempt: int,
persistent: bool,
on_retry_wait: Callable[[str], Awaitable[None]] | None = None,
) -> None:
remaining = max(0.0, delay)
while remaining > 0:
if on_retry_wait:
kind = "persistent retry" if persistent else "retry"
await on_retry_wait(
f"Model request failed, {kind} in {max(1, int(round(remaining)))}s "
f"(attempt {attempt})."
)
chunk = min(remaining, self._RETRY_HEARTBEAT_CHUNK)
await asyncio.sleep(chunk)
remaining -= chunk
async def _run_with_retry(
self,
call: Callable[..., Awaitable[LLMResponse]],
kw: dict[str, Any],
original_messages: list[dict[str, Any]],
*,
retry_mode: str,
on_retry_wait: RetryEventCallback | None,
on_retry_exhausted: RetryEventCallback | None,
should_retry_guard: Callable[[], bool] | None = None,
on_stream_recover: Callable[[], Awaitable[None]] | None = None,
) -> LLMResponse:
attempt = 0
delays = list(self._CHAT_RETRY_DELAYS)
persistent = retry_mode == "persistent"
last_response: LLMResponse | None = None
last_error_key: str | None = None
identical_error_count = 0
while True:
attempt += 1
response = await call(**kw)
if response.finish_reason != "error":
return response
last_response = response
if should_retry_guard is not None and not should_retry_guard():
is_timeout = (response.error_kind or "").lower() == "timeout"
if is_timeout:
if on_stream_recover:
logger.warning(
"LLM stream stalled after content was emitted; "
"starting a new stream segment and retrying"
)
await on_stream_recover()
else:
logger.warning(
"LLM stream stalled after content was emitted; "
"suppressing delta callbacks and retrying"
)
kw.setdefault("on_content_delta", None)
kw["on_content_delta"] = None
kw["on_thinking_delta"] = None
kw["on_tool_call_delta"] = None
should_retry_guard = None
else:
logger.warning(
"LLM stream failed after content was emitted; skipping retry"
)
return response
error_key = ((response.content or "").strip().lower() or None)
if error_key and error_key == last_error_key:
identical_error_count += 1
else:
last_error_key = error_key
identical_error_count = 1 if error_key else 0
if not self.is_transient_response(response):
stripped = self._strip_image_content(kw["messages"])
provider_context = kw.get("provider_context")
stripped_context: ProviderCallContext | None = None
if isinstance(provider_context, ProviderCallContext):
state = provider_context.conversation_state
if state is not None and (
stripped is not None
or self._strip_image_content(state.pending_messages) is not None
or self._contains_image_content(state.payload)
):
# Provider-owned payloads may retain earlier input_image items.
# Rebuild from the stripped public transcript for this retry.
stripped_context = ProviderCallContext(
context_window_tokens=(
provider_context.context_window_tokens
),
session_id=provider_context.session_id,
)
if stripped is not None or stripped_context is not None:
logger.warning(
"Non-transient LLM error with image content, retrying without images"
)
retry_kw = dict(kw)
if stripped is not None:
retry_kw["messages"] = stripped
if stripped_context is not None:
retry_kw["provider_context"] = stripped_context
result = await call(**retry_kw)
# Permanently strip images from the original messages so
# subsequent iterations do not repeat the error-retry cycle.
if result.finish_reason != "error":
self._strip_image_content_inplace(original_messages)
return result
return response
if persistent and identical_error_count >= self._PERSISTENT_IDENTICAL_ERROR_LIMIT:
logger.warning(
"Stopping persistent retry after {} identical transient errors: {}",
identical_error_count,
(response.content or "")[:120].lower(),
)
if on_retry_exhausted:
await on_retry_exhausted(
f"Persistent retry stopped after {identical_error_count} identical errors."
)
return response
if not persistent and attempt > len(delays):
logger.warning(
"LLM request failed after {} attempts, giving up: {}",
attempt,
(response.content or "")[:120].lower(),
)
if on_retry_exhausted:
await on_retry_exhausted(
f"Model request failed after {attempt} attempts, giving up."
)
break
retry_after = self._extract_retry_after_from_response(response)
base_delay = delays[min(attempt - 1, len(delays) - 1)]
delay = retry_after + RETRY_AFTER_BUFFER if retry_after else base_delay
if persistent:
delay = min(delay, self._PERSISTENT_MAX_DELAY)
logger.warning(
"LLM transient error (attempt {}{}), retrying in {}s: {}",
attempt,
"+" if persistent and attempt > len(delays) else f"/{len(delays)}",
int(round(delay)),
(response.content or "")[:120].lower(),
)
await self._sleep_with_heartbeat(
delay,
attempt=attempt,
persistent=persistent,
on_retry_wait=on_retry_wait,
)
return last_response if last_response is not None else await call(**kw) # pyright: ignore[reportUnnecessaryComparison]
@abstractmethod
def get_default_model(self) -> str:
"""Get the default model for this provider."""
pass