# Evidence: executor-v2-output-contract

## Context Used

- `devflow/projects/2026-07-07-executor-evidence-output-contract`: V1 evidence-attribution contract kept `user_facing_answer`.
- `devflow/projects/2026-07-02-chat-verifier-agent`: Verifier consumes explicit inputs and should not see intermediate reasoning.
- `devflow/projects/2026-07-04-evidence-trace-hardening`: evidence summaries and tool invocation references are the evidence foundation.
- `mvp/issues/design-notes/executor-structured-output-v2.md`: staged implementation design; stage one is Executor V2 output contract.

## Code Evidence

- `src/main/resources/prompts/chat-executor-prompt.md`: V2 contract now uses `answer_version="executor_evidence_v2"` and removes final-expression fields.
- `src/main/java/com/superbiz/agent/service/ChatService.java`: PASS path now tries V1 `user_facing_answer`, then renders V2 structured output to readable Chinese.
- `src/main/resources/prompts/chat-verifier-prompt.md`: `user_facing_answer` is now described as compatibility-only.
- `src/test/java/com/superbiz/agent/hook/VerifierInputHookTest.java`: V2 structured output without `user_facing_answer` parses successfully.
- `src/test/java/com/superbiz/agent/service/ChatServiceSequentialAgentTest.java`: PASS + V2 output renders Chinese and does not expose raw JSON.

## Key Finding

The previous V1 contract intentionally kept `user_facing_answer`, but the V2 staged design intentionally removes it. This is an internal Agent contract break, mitigated by a temporary renderer until Composer is implemented.