feat(learning-harness): chat endpoint independent of embeddings, with the DeepSeek adapter

Task 1.2. Detectors, the classifier's model tier, the proposer and the judge
resolve one chat endpoint: an explicit override first, then the scripted client
flag, then an endpoint named in the config, then DeepSeek, then OpenRouter.
Prove-order retrieval keeps its own embedding endpoint untouched, because the
chat provider we default to offers none.

The adapter handles the provider's documented quirks: thinking is on by default
there and silently ignores temperature, so it is disabled explicitly; the
reasoning field is kept on the reply for the caller to replay across tool turns;
JSON mode has no schema and occasionally returns empty content, so one retry is
built in, never a loop; token log-probabilities are requested only when the
caller wants them, and their mean is what lets the classifier abstain.

Cost comes from the provider's own usage fields, cache hits priced separately,
and a model with no recorded price reports no cost rather than a made-up one.
The endpoint record deliberately holds no key, so it is safe to journal.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
This commit is contained in:
Marius Ciepluch
2026-09-06 09:10:19 +02:00
co-authored by Claude Opus 5
parent 289648338c
commit 944df86d12
5 changed files with 452 additions and 3 deletions
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"""The chat endpoint, resolved independently of embeddings (learning-harness, Req 6.6).
Detectors, the classifier's model tier, the proposer and the judge all talk to one chat endpoint;
prove-order retrieval keeps its own embedding endpoint, because the chat provider we default to has
none. Resolution order is explicit override, the scripted client flag, an endpoint named in the
config, DeepSeek, then OpenRouter. ``DeepSeekChatClient`` adapts the provider's quirks: thinking is
on by default there and silently ignores ``temperature``, so it is disabled explicitly; the reasoning
field is kept on the reply for the caller to replay across tool turns; JSON mode has no schema and
occasionally returns empty content, so one retry is built in. Prices are data, and an unpriced model
reports no cost rather than a made-up one.
"""
from __future__ import annotations
import os
from collections.abc import Mapping, Sequence
from dataclasses import dataclass
from typing import Literal
from ..config import ResolvedConfig
from ..provider.openrouter import OpenRouterChatClient, OpenRouterError
from ..tool_hunter import CLIENT_ENV, ChatClient, ChatResponse, chat_response_from_message, scripted_hunter_client
DEEPSEEK_BASE_URL = "https://api.deepseek.com" # no version suffix: the platform rejects /v1
DEEPSEEK_KEY_ENV = "DEEPSEEK_API_KEY"
DEEPSEEK_BASE_ENV = "DEEPSEEK_BASE_URL"
OPENROUTER_BASE_URL = "https://openrouter.ai/api/v1"
DEFAULT_DETECTOR_MODEL = "deepseek-v4-flash"
DEFAULT_JUDGE_MODEL = "deepseek-v4-pro"
Provider = Literal["deepseek", "openrouter", "custom", "scripted"]
_SCRIPTED_FLAGS = frozenset({"scripted", "script", "dump", "dump-only", "unsafe", "unsafe-snippet"})
@dataclass(frozen=True)
class Prices:
"""USD per million tokens. DeepSeek platform pricing, peak rate, recorded 2026-09-06."""
cache_hit_per_m: float
input_per_m: float
output_per_m: float
_PRICES: dict[str, Prices] = {
"deepseek-v4-flash": Prices(cache_hit_per_m=0.014, input_per_m=0.44, output_per_m=1.32),
"deepseek-v4-flash-vision-exp": Prices(cache_hit_per_m=0.014, input_per_m=0.44, output_per_m=1.32),
"deepseek-v4-pro": Prices(cache_hit_per_m=0.044, input_per_m=1.32, output_per_m=3.96),
}
def price_of(model: str) -> Prices | None:
return _PRICES.get(model.strip())
@dataclass(frozen=True)
class ChatEndpoint:
"""What the run should record about where the model calls went. Never holds the key."""
provider: Provider
base_url: str
thinking: bool # the provider's models reason by default, so the adapter disables it explicitly
prices: Prices | None = None
def cost(self, usage: Mapping[str, object] | None) -> float | None:
"""Dollars for one call from the provider's own usage fields, or None when the model has no recorded price."""
if self.prices is None or not isinstance(usage, Mapping):
return None
cache_hit = _tokens(usage.get("prompt_cache_hit_tokens"))
miss = usage.get("prompt_cache_miss_tokens")
input_tokens = _tokens(miss) if miss is not None else max(_tokens(usage.get("prompt_tokens")) - cache_hit, 0)
output_tokens = _tokens(usage.get("completion_tokens"))
return (
cache_hit * self.prices.cache_hit_per_m + input_tokens * self.prices.input_per_m + output_tokens * self.prices.output_per_m
) / 1_000_000
class DeepSeekChatClient:
"""Adapt an OpenAI-shaped chat client to what detectors and the classifier need."""
def __init__(self, client: OpenRouterChatClient, *, disable_thinking: bool = True, endpoint: ChatEndpoint | None = None) -> None:
self._client = client
self._disable_thinking = disable_thinking
self.endpoint = endpoint
self.usage: list[dict[str, object]] = [] # one entry per call, for the round's cost meter
def complete(
self,
*,
model: str,
messages: list[dict[str, object]],
tools: list[dict[str, object]],
timeout_seconds: int = 60,
json_object: bool = False,
logprobs: bool = False,
) -> ChatResponse:
response = self._call(
model=model, messages=messages, tools=tools, timeout_seconds=timeout_seconds, json_object=json_object, logprobs=logprobs
)
if json_object and not (response.content or "").strip():
response = self._call(
model=model, messages=messages, tools=tools, timeout_seconds=timeout_seconds, json_object=json_object, logprobs=logprobs
) # documented behaviour: JSON mode occasionally returns empty content. One retry, never a loop.
return response
def cost_usd(self) -> float:
"""Recorded cost of the calls made so far; calls whose model has no price contribute nothing."""
if self.endpoint is None:
return 0.0
return sum(self.endpoint.cost(entry) or 0.0 for entry in self.usage)
def _call(
self,
*,
model: str,
messages: Sequence[Mapping[str, object]],
tools: Sequence[Mapping[str, object]],
timeout_seconds: int,
json_object: bool,
logprobs: bool,
) -> ChatResponse:
extra: dict[str, object] = {}
if self._disable_thinking:
extra["thinking"] = {"type": "disabled"} # otherwise temperature is silently ignored
if json_object:
extra["response_format"] = {"type": "json_object"}
if logprobs:
extra["logprobs"] = True
extra["top_logprobs"] = 1
raw = getattr(self._client, "complete_chat_raw", None)
if callable(raw):
payload = raw(
model=model, messages=list(messages), tools=list(tools) or None, timeout_seconds=timeout_seconds, extra_body=extra
)
usage = payload.get("usage") if isinstance(payload, dict) else None
if isinstance(usage, dict):
self.usage.append(dict(usage))
message = _message_of(payload)
else: # a stub or a client without the raw call
message = self._client.complete_chat(
model=model, messages=list(messages), tools=list(tools) or None, timeout_seconds=timeout_seconds, extra_body=extra
)
return chat_response_from_message(message)
def resolve_chat_endpoint(config: ResolvedConfig, *, override: ChatClient | None = None) -> tuple[ChatClient, ChatEndpoint] | None:
"""The chat client for detectors, classifier, proposer and judge, with what to record about it."""
if override is not None:
return override, ChatEndpoint(provider="scripted", base_url="", thinking=False)
flag = os.environ.get(CLIENT_ENV, "").strip().lower()
if flag in _SCRIPTED_FLAGS:
return scripted_hunter_client(flag), ChatEndpoint(provider="scripted", base_url="", thinking=False)
model = resolve_models(config)[0]
configured = config.models.chat_base_url
key_env = config.models.chat_api_key_env
if configured or key_env:
key = os.environ.get(key_env or DEEPSEEK_KEY_ENV, "")
base_url = configured or DEEPSEEK_BASE_URL
return _deepseek_client(key, base_url, model, provider=_provider_of(base_url))
deepseek_key = os.environ.get(DEEPSEEK_KEY_ENV)
if deepseek_key:
return _deepseek_client(deepseek_key, os.environ.get(DEEPSEEK_BASE_ENV, DEEPSEEK_BASE_URL), model, provider="deepseek")
if os.environ.get("OPENROUTER_API_KEY"):
try:
client = OpenRouterChatClient.from_env()
except OpenRouterError:
return None
endpoint = ChatEndpoint(provider="openrouter", base_url=client.base_url, thinking=False, prices=price_of(model))
return DeepSeekChatClient(client, disable_thinking=False, endpoint=endpoint), endpoint
return None
def resolve_models(config: ResolvedConfig) -> tuple[str, str]:
"""(detector model, judge model). `[learning]` wins, then `[models]`, then the shipped defaults."""
detector = config.learning.detector_model or config.models.hunter or DEFAULT_DETECTOR_MODEL
judge = config.learning.judge_model or config.models.judge or DEFAULT_JUDGE_MODEL
return detector, judge
def _deepseek_client(key: str, base_url: str, model: str, *, provider: Provider) -> tuple[ChatClient, ChatEndpoint]:
endpoint = ChatEndpoint(provider=provider, base_url=base_url.rstrip("/"), thinking=True, prices=price_of(model))
client = OpenRouterChatClient(api_key=key, base_url=endpoint.base_url)
return DeepSeekChatClient(client, endpoint=endpoint), endpoint
def _provider_of(base_url: str) -> Provider:
host = base_url.lower()
if "deepseek" in host:
return "deepseek"
return "openrouter" if "openrouter" in host else "custom"
def _message_of(payload: object) -> Mapping[str, object]:
if isinstance(payload, Mapping):
choices = payload.get("choices")
if isinstance(choices, Sequence) and choices and isinstance(choices[0], Mapping):
message = choices[0].get("message")
if isinstance(message, Mapping):
return message
return {}
def _tokens(value: object) -> int:
return int(value) if isinstance(value, int | float) else 0
__all__ = [
"DEEPSEEK_BASE_URL",
"DEFAULT_DETECTOR_MODEL",
"DEFAULT_JUDGE_MODEL",
"ChatEndpoint",
"DeepSeekChatClient",
"Prices",
"price_of",
"resolve_chat_endpoint",
"resolve_models",
]