fix(websocket): avoid fresh retry for tool-output deltas

[zvladru]

Problem

Codex Desktop can send a response.create request with previous_response_id and an input delta that contains only function_call_output items. That payload is valid only while the upstream response history remains anchored by previous_response_id.

The proxy's fresh retry preparation could previously treat a multi-item client resend as safe to replay without that upstream anchor. For tool-output-only deltas, that creates a fresh request containing function_call_output items without the matching prior function_call items, which can be rejected upstream with errors like:

No tool call found for function call output with call_id ...

Changes

• Require tool-output items in a fresh replay candidate to be self-contained: each function_call_output, custom_tool_call_output, or apply_patch_call_output must have a matching earlier call item with the same call_id in the replayed input.
• Reject tool-output-only deltas and output-before-call histories as fresh-retry candidates.
• Preserve the normal anchored request path with previous_response_id; this only disables unsafe fresh replay construction.
• Keep self-contained full histories retry-safe.

Impact

This prevents the proxy from manufacturing an invalid fresh retry for Codex tool-output deltas. Normal text requests and full self-contained replay payloads continue to behave as before.

Tests

• uv run pytest -q tests/unit/test_proxy_utils.py::test_prepare_websocket_response_create_request_does_not_fresh_retry_tool_output_delta tests/unit/test_proxy_utils.py::test_prepare_websocket_response_create_request_captures_client_full_resend_anchor_replay tests/unit/test_proxy_utils.py::test_websocket_client_previous_response_full_resend_retry_rejects_tool_output_delta tests/unit/test_proxy_utils.py::test_websocket_client_previous_response_full_resend_retry_rejects_output_before_call tests/unit/test_proxy_utils.py::test_websocket_client_previous_response_full_resend_retry_allows_self_contained_tool_history

[chatgpt-codex-connector]

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[zvladru]

Addressed the automated review feedback in ad09257d by documenting the tool-output-only retry boundary in the OpenSpec source of truth.

@codex review

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: ad09257de2

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Apply guard to injected-anchor fresh retries

This self-contained check only runs for client-supplied previous_response_id payloads. The Codex-session full-resend path still injects previous_response_id from session_anchor and then marks original_full_resend_payload retry-safe whenever the fresh text body exists; when that stored prefix is a tool-output delta, a later previous_response_not_found will still replay those function_call_output items without their matching calls and hit the same upstream rejection. Please apply the same guard before marking the injected-anchor fresh body safe.

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