A Claude refusal (HTTP 200, stop_reason="refusal", empty content) was
laundered into a generic retry loop and surfaced as a misleading
"rate limited / invalid response" or "no content after retries" error,
burning paid attempts reproducing a deterministic refusal.
This hit two distinct paths:
- Direct Anthropic (anthropic_messages): validate_response rejected the
empty-content refusal *before* normalize_response mapped refusal ->
content_filter, so it fell into the invalid-response retry loop.
- Nous Portal / OpenAI-compatible (chat_completions): the portal surfaces
a Claude refusal via message.refusal with empty content, which sailed
past validation and died in the empty-response retry loop.
Fix (one unified content_filter dispatch for all backends):
- AnthropicTransport.validate_response: accept empty content when
stop_reason == "refusal" so it flows to normalize_response.
- ChatCompletionsTransport.normalize_response: promote message.refusal to
content + a content_filter finish reason.
- conversation_loop: handle finish_reason == "content_filter" - fire the
api_request_error hook (content_policy_blocked), try a configured
fallback once, else return a clear terminal refusal message. Never retry
a deterministic refusal.
Supersedes #43084, which fixed only the direct-Anthropic path and could
not reach the chat_completions/portal path.
Tests: transport-level (validate_response refusal, message.refusal
promotion) + end-to-end loop (refusal surfaced, exactly one API call).
(cherry picked from commit 01f546f92c)
Remove unused imports (F401) and duplicate/shadowed import
redefinitions (F811) across the codebase using ruff's safe
autofixes. No behavioral changes -- imports only.
- ~1400 safe autofixes applied across 644 files (net -1072 lines)
- __init__.py re-exports preserved (excluded from F401 removal so
public re-export surfaces stay intact)
- Re-exports that are imported or monkeypatched by tests but look
unused in their defining module are kept with explicit # noqa:
F401 (gateway/run.py load_dotenv; run_agent re-exports from
agent.message_sanitization, agent.context_compressor,
agent.retry_utils, agent.prompt_builder, agent.process_bootstrap,
agent.codex_responses_adapter)
- Unsafe F841 (unused-variable) fixes deliberately skipped -- those
can change behavior when the RHS has side effects
- ruff lints remain disabled in pyproject.toml (only PLW1514 is
selected); this is a one-time cleanup, not a config change
Verification:
- python -m compileall: clean
- pytest --collect-only: all 27161 tests collect (zero import errors)
- core entry points import clean (run_agent, model_tools, cli,
toolsets, hermes_state, batch_runner, gateway)
- static scan: every name any test imports directly from an edited
module still resolves
Anthropic's API can legitimately return content=[] with stop_reason="end_turn"
when the model has nothing more to add after a turn that already delivered the
user-facing text alongside a trivial tool call (e.g. memory write). The transport
validator was treating that as an invalid response, triggering 3 retries that
each returned the same valid-but-empty response, then failing the run with
"Invalid API response after 3 retries."
The downstream normalizer already handles empty content correctly (empty loop
over response.content, content=None, finish_reason="stop"), so the only fix
needed is at the validator boundary.
Tests:
- Empty content + stop_reason="end_turn" → valid (the fix)
- Empty content + stop_reason="tool_use" → still invalid (regression guard)
- Empty content without stop_reason → still invalid (existing behavior preserved)
