Admins often need another account with the same provider and routing configuration. Duplicate on the server so credentials never return to the browser, preserve exact group priorities atomically, start the copy paused, and recover the same copy after ambiguous idempotency-store failures.
Constraint: Admin account responses redact credentials, so duplication must remain server-side
Constraint: OAuth and setup-token credentials rotate and must not be shared across account rows
Rejected: Copy raw account JSON to the clipboard | exposes credentials outside the server
Rejected: Duplicate rotating credentials | account-scoped refresh locks can race token rotation
Confidence: high
Scope-risk: moderate
Reversibility: clean
Directive: Keep copies paused, avoid automatic upstream probes, and exclude rotating credential types unless token ownership is redesigned
Tested: Targeted Go tests, Go vet, server build; frontend lint, typecheck, Vitest suite, production build; integration test compiled
Not-tested: Docker-backed PostgreSQL execution because Docker is unavailable
Related: Wei-Shaw/sub2api#1379
Related: Wei-Shaw/sub2api#2928
Skip the Responses API intermediate representation on the /v1/messages
force-chat path. Previously every streaming token ran through two state
machines (CC→Responses→Anthropic); now it runs through one (CC→Anthropic).
New file backend/internal/pkg/apicompat/chatcompletions_anthropic_bridge.go:
- AnthropicToChatCompletionsRequest: request-side direct conversion
- ChatCompletionsResponseToAnthropic: non-stream response direct conversion
- ChatCompletionsChunkToAnthropicEvents + Finalize: single streaming state machine
openai_gateway_messages_chat_fallback.go rewired to use the direct bridge.
Existing 7 ForceChatCompletions end-to-end tests pass unchanged; 22 new
unit tests added including equivalence tests vs the double-conversion path.
Add a dedicated client first-message timeout while preserving the legacy 30-second default.
Use the resolved value for both the WebSocket read deadline and structured timeout logs, and document tuning for large requests or slow links.
Add configuration, validation, handler, and resolver regression coverage.
Refs #4158
ChatGPT OAuth may normalize explicit image size controls to auto while returning smaller raster bytes. Decode final image headers so Images API metadata and tier billing reflect the actual output for both streaming and non-streaming OAuth responses.