diff --git a/devflow/index.md b/devflow/index.md
index 3ed2022..b75a82e 100644
--- a/devflow/index.md
+++ b/devflow/index.md
@@ -5,6 +5,7 @@
 | 日期 | slug | 领域 | 关键词 | 状态 |
 |---|---|---|---|---|
 | 2026-07-05 | diagnosis-playbook-skills | Agent Skill/Playbook | read_skill, diagnosis playbook, progressive disclosure, payment timeout, MySQL pool, Redis timeout | openspec/changes/diagnosis-playbook-skills | implemented |
+| 2026-07-07 | executor-evidence-output-contract | Chat质量门禁/证据归因 | Executor structured output, evidence bindings, Verifier structured claims, LOW_CONFID, hallucination | openspec/changes/executor-evidence-output-contract | proposed |
 | 2026-07-06 | rag-eval-pipeline-closure | RAG/评测/回归闭环 | lookupResult fixture, LookupKnowledgeTool snapshot, evidenceBlocks, contextPack, retrievalTrace, rerankTrace, baseline diff, fallback case | devflow/projects/2026-07-06-rag-eval-pipeline-closure | archived |
 | 2026-07-06 | modular-rag-pipeline | RAG/Agent工具/证据链 | modular RAG, lookup_knowledge, evidenceBlocks, contextPack, rerank, retrievalTrace, L0 hint, unfiltered retry | openspec/changes/archive/2026-07-06-modular-rag-pipeline | archived |
 | 2026-07-05 | mvp-demo-interview-runbook | MVP Demo/Interview | Plan C, payment timeout, runbook, trace checklist, demo script | openspec/changes/archive/2026-07-05-mvp-demo-interview-runbook | archived |
diff --git a/devflow/projects/2026-07-07-executor-evidence-output-contract/acceptance.md b/devflow/projects/2026-07-07-executor-evidence-output-contract/acceptance.md
new file mode 100644
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--- /dev/null
+++ b/devflow/projects/2026-07-07-executor-evidence-output-contract/acceptance.md
@@ -0,0 +1,16 @@
+# Acceptance: executor-evidence-output-contract
+
+## Draft Acceptance
+
+- [x] Issue exists: `mvp/issues/executor-evidence-attribution-hallucination.md`.
+- [x] OpenSpec change artifacts exist.
+- [x] devflow tracking files exist.
+- [x] OpenSpec validation passes.
+- [x] Implementation updates Chat Executor prompt.
+- [x] Implementation passes structured Executor output to Verifier.
+- [x] Verifier prefers structured claims and still falls back safely.
+- [x] Focused tests cover parsing, payload assembly, and unsupported confirmed claims.
+
+## Notes
+
+This project is currently in proposal/design stage. Runtime code is intentionally not changed yet.
diff --git a/devflow/projects/2026-07-07-executor-evidence-output-contract/brief.md b/devflow/projects/2026-07-07-executor-evidence-output-contract/brief.md
new file mode 100644
index 0000000..f918408
--- /dev/null
+++ b/devflow/projects/2026-07-07-executor-evidence-output-contract/brief.md
@@ -0,0 +1,23 @@
+# Brief: executor-evidence-output-contract
+
+## Summary
+
+Executor currently returns natural-language diagnosis answers that may mix confirmed evidence, runbook guidance, historical patterns, and unsupported inference. Verifier catches many unsupported facts, but only after extracting claims from prose.
+
+This project defines a structured Executor evidence-attribution contract and updates the Verifier input/verification path to consume it.
+
+## Goal
+
+Make Chat Executor output machine-checkable so confirmed claims are explicitly bound to current-session evidence, while hypotheses and evidence gaps remain visibly separate.
+
+## Scope
+
+- Chat Executor prompt contract.
+- Executor structured output parsing.
+- Verifier payload extension.
+- Chat Verifier prompt behavior.
+- Focused tests/eval fixtures.
+
+## Related OpenSpec
+
+`openspec/changes/executor-evidence-output-contract/`
diff --git a/devflow/projects/2026-07-07-executor-evidence-output-contract/decisions.md b/devflow/projects/2026-07-07-executor-evidence-output-contract/decisions.md
new file mode 100644
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--- /dev/null
+++ b/devflow/projects/2026-07-07-executor-evidence-output-contract/decisions.md
@@ -0,0 +1,71 @@
+# Decisions: executor-evidence-output-contract
+
+## sm-flow Progress
+
+### Clarify
+
+Entry summary: recent Chat diagnosis sessions are `LOW_CONFID` because Executor presents unsupported or weakly supported details as confirmed facts after successful tool calls.
+
+Slug: `executor-evidence-output-contract`
+
+Scale: standard. This affects prompts, verifier input assembly, parsing behavior, and tests, but does not require a database schema change.
+
+### Context
+
+Relevant history:
+
+- `executor-action-memory-relevance`: Executor already has retrieval quality constraints and should avoid repeated `lookup_knowledge`.
+- `chat-verifier-agent`: Verifier should not see intermediate reasoning; it receives explicit `original_query`, `executor_final_answer`, `tool_trace_summary`, and `retry_context`.
+- `evidence-trace-hardening`: evidence-bearing tools persist stable traces and no-evidence semantics.
+- `modular-rag-pipeline`: `lookup_knowledge` exposes evidence blocks and context packs; L0 hints are not fact evidence.
+
+Current code shape:
+
+- `src/main/resources/prompts/chat-executor-prompt.md` is the Chat Executor prompt.
+- `src/main/resources/prompts/executor-prompt.md` is for the AiOps flow and is not the target of this Chat change.
+- `VerifierInputHook` currently builds a payload with `original_query`, `executor_final_answer`, `tool_trace_summary`, and `retry_context`.
+- Verifier prompt currently extracts facts from `executor_final_answer`.
+
+### Grill
+
+Question: Should Executor output only JSON or JSON plus readable answer?
+
+Decision: use one JSON object containing both machine fields and `user_facing_answer`. This avoids losing a readable Chinese answer while giving Verifier structured claims.
+
+Question: Should evidence binding use `chunk_id`?
+
+Decision: no. Use generic binding fields because `query_logs` and `query_metrics` do not naturally expose RAG chunks.
+
+Question: Should Verifier trust Executor-provided claims completely?
+
+Decision: no. Verifier should verify structured claims first, then scan `user_facing_answer` for extra confirmed-sounding facts omitted from `claims`.
+
+Question: What happens when Executor JSON is malformed?
+
+Decision: preserve raw final answer, mark parse failure, and fall back to existing natural-language verification.
+
+### Specify
+
+OpenSpec artifacts:
+
+- `proposal.md`: why and scope
+- `design.md`: contract, verifier behavior, risks
+- `specs/chat-verifier-agent/spec.md`: modified and added requirements
+- `tasks.md`: implementation checklist
+
+### Audit
+
+Cross-artifact alignment:
+
+- Issue describes evidence attribution hallucination.
+- Proposal scopes the fix to Executor output and Verifier consumption.
+- Design preserves existing verifier isolation.
+- Spec adds observable behavior without changing database schema.
+- Tasks remain implementation-oriented and unchecked.
+
+Interface impact:
+
+- Prompt/output contract: L2 internal Agent contract change.
+- Verifier payload: L2 internal structured input extension.
+- Database schema: no change.
+- External HTTP API: no intended change.
diff --git a/devflow/projects/2026-07-07-executor-evidence-output-contract/evidence.md b/devflow/projects/2026-07-07-executor-evidence-output-contract/evidence.md
new file mode 100644
index 0000000..38002a0
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+++ b/devflow/projects/2026-07-07-executor-evidence-output-contract/evidence.md
@@ -0,0 +1,17 @@
+# Evidence: executor-evidence-output-contract
+
+## Repository Evidence
+
+- `chat-executor-prompt.md` currently requires using real tool data but does not require a structured evidence-attribution output.
+- `chat-verifier-prompt.md` currently extracts facts from `executor_final_answer` prose and compares them with `tool_trace_summary`.
+- `VerifierInputHook` currently provides `original_query`, `executor_final_answer`, `tool_trace_summary`, and `retry_context`.
+- `openspec/specs/chat-verifier-agent/spec.md` already requires explicit verifier inputs, auditable evidence refs, fixed verdicts, and low-confidence handling.
+- `openspec/specs/evidence-trace-hardening/spec.md` already distinguishes failed, no-hit, deduped, and successful evidence-tool traces.
+
+## Runtime Evidence From Recent Sessions
+
+Recent MySQL inspection showed repeated `LOW_CONFID` verifier results with many `no_evidence` facts. Typical unsupported claims included OOM, Full GC frequency, specific slow SQL timings, lock waits, and service-specific timeout details that were not supported by current-session tool traces.
+
+## Design Evidence
+
+This change preserves the previous design that Verifier should not inspect intermediate reasoning. The new structured output is still final Executor output, not hidden chain-of-thought.
diff --git a/mvp/eval/schema.md b/mvp/eval/schema.md
index 21e5130..5d611d3 100644
--- a/mvp/eval/schema.md
+++ b/mvp/eval/schema.md
@@ -58,6 +58,7 @@ trace fixture 是一次 Agent 运行后的“留痕快照”。评测器不会
 | `session.answer` | Agent 最终给用户的回答 | 用来检查根因关键词和禁用词 |
 | `session.totalDurationMs` | 这次运行耗时 | 进入报告，帮助观察性能是否明显变差 |
 | `session.selfEvaluation.verifier_evaluation.verdict` | Verifier 对最终回答的判断 | 必须存在，并且要落在 case 的 `allowedVerdicts` 里 |
+| `session.selfEvaluation.verifier_evaluation.executor_structured_output.claims[*].evidence_bindings` | Executor 结构化输出里的确认事实证据绑定 | 如果 trace 中存在结构化 Executor 输出，每条 confirmed claim 必须有证据绑定 |
 | `session.selfEvaluation.verifier_evaluation.tool_trace_summary[*].tool_name` | Verifier 总结里看到的工具证据 | 用来补充判断证据工具是否出现 |
 | `toolInvocations[*].toolName` | Agent 实际调用过的工具名 | 用来检查 `requiredEvidenceTools` 是否满足 |
 | `toolInvocations[*].success` | 工具调用是否成功 | 当前主要保留在 trace 里，后续可以升级成更严格的成功率检查 |
diff --git a/openspec/changes/executor-evidence-output-contract/design.md b/openspec/changes/executor-evidence-output-contract/design.md
new file mode 100644
index 0000000..5a30202
--- /dev/null
+++ b/openspec/changes/executor-evidence-output-contract/design.md
@@ -0,0 +1,161 @@
+## Context
+
+Current Chat flow explicitly runs `Planner -> Executor -> Verifier`. `VerifierInputHook` builds a structured verifier payload containing:
+
+- `original_query`
+- `executor_final_answer`
+- `tool_trace_summary`
+- `retry_context`
+
+This satisfies the earlier design goal that Verifier should not see Planner/Executor intermediate reasoning. However, Executor's answer is still natural language. Verifier must infer claims from prose, then compare those claims to tool traces. Recent low-confidence sessions show that Executor often converts weak or unrelated evidence into confirmed conclusions before Verifier sees it.
+
+The fix should move evidence attribution earlier: Executor must state which claims are confirmed, which evidence supports them, and which points remain hypotheses or gaps.
+
+## Goals / Non-Goals
+
+**Goals:**
+
+- Make Executor final output machine-checkable.
+- Separate confirmed claims, hypotheses, recommended actions, and missing information.
+- Make every confirmed claim bind to concrete tool evidence identifiers or excerpts.
+- Let Verifier consume structured claims directly instead of reconstructing all facts from prose.
+- Preserve Verifier input isolation from intermediate reasoning.
+- Preserve existing behavior when Executor output is malformed by falling back to natural-language verification and low-confidence handling.
+
+**Non-Goals:**
+
+- Do not add database tables or columns.
+- Do not change evidence tool method signatures.
+- Do not let Verifier call tools.
+- Do not require full raw tool outputs in verifier input.
+- Do not make user-facing answers become raw JSON-only unless the product layer explicitly chooses that rendering.
+
+## Decisions
+
+### Decision: Executor emits an evidence-attribution contract
+
+Executor final output SHALL be a single JSON object. The recommended contract is:
+
+```json
+{
+  "answer_version": "executor_evidence_v1",
+  "diagnosis_summary": "1-2 sentence summary using only supported facts",
+  "claims": [
+    {
+      "claim_id": "claim-1",
+      "claim_type": "root_cause",
+      "claim_text": "The payment-service connection pool is saturated",
+      "support_level": "direct",
+      "evidence_bindings": [
+        {
+          "source_type": "tool_trace",
+          "source_id": "trace-1",
+          "tool_name": "query_metrics",
+          "source_invocation_ids": [101],
+          "evidence_excerpt": "active connections reached max pool size"
+        }
+      ]
+    }
+  ],
+  "hypotheses": [
+    {
+      "hypothesis_text": "A connection leak may be contributing",
+      "basis": "metrics show saturation, but no leak evidence was returned",
+      "needed_evidence": ["connection lifetime metrics", "leak detection logs"]
+    }
+  ],
+  "recommended_actions": [
+    {
+      "action_text": "Check HikariCP active/idle/pending connection metrics",
+      "reason": "Needed to confirm pool saturation scope",
+      "evidence_bindings": []
+    }
+  ],
+  "missing_info": [
+    "No log evidence confirming a connection leak was returned"
+  ],
+  "user_facing_answer": "Chinese answer rendered from the same confirmed claims, hypotheses, actions, and gaps"
+}
+```
+
+Rationale: this keeps the machine contract explicit while still allowing the product to return a readable Chinese answer.
+
+### Decision: Evidence binding uses generic source fields
+
+`chunk_id` alone is too specific to `lookup_knowledge`. The binding shape SHALL support all evidence-bearing tools:
+
+- `source_type`: `tool_trace`, `lookup_evidence_block`, or another stable source family
+- `source_id`: `tool_trace_summary.trace_ref`, evidence block id, or equivalent stable id
+- `tool_name`: evidence tool name when available
+- `source_invocation_ids`: persisted `tool_invocation` ids when available
+- `evidence_excerpt`: bounded excerpt copied or summarized from tool evidence
+
+Rationale: `query_logs`, `query_metrics`, and `lookup_knowledge` expose evidence differently. A generic binding prevents the prompt contract from overfitting to RAG chunks.
+
+### Decision: Confirmed claims are stricter than hypotheses and actions
+
+Confirmed `claims` SHALL contain only facts supported by current-session evidence. Runbook instructions, skill guidance, and historical case patterns SHALL NOT appear as confirmed claims unless the current tool trace supports that exact fact.
+
+Unsupported but useful diagnostic ideas SHALL be placed under `hypotheses` or `recommended_actions`.
+
+Rationale: this directly addresses the observed hallucination: turning plausible patterns into current incident facts.
+
+### Decision: Verifier prefers structured claims but keeps fallback
+
+Verifier prompt SHALL use this order:
+
+1. If `executor_structured_output.claims` is valid, verify each claim directly.
+2. Also scan `user_facing_answer` for extra confirmed-sounding facts not present in `claims`; mark them as facts to check.
+3. If the structured output is missing or invalid, fall back to the existing natural-language extraction from `executor_final_answer`.
+
+Invalid structured output SHALL NOT crash the flow. It SHOULD produce a fallback verifier decision and make malformed structure visible in `verifier_evaluation`.
+
+Rationale: the new contract should improve precision without making runtime brittle.
+
+### Decision: Verifier still does not see intermediate reasoning
+
+The verifier payload MAY add:
+
+- `executor_structured_output`
+- `executor_output_parse_status`
+
+It SHALL continue to exclude Planner reasoning, Executor intermediate reasoning, and raw conversation noise.
+
+Rationale: this preserves the original verifier design: verify the final answer and tool traces, not hidden reasoning.
+
+### Decision: User-facing output remains Chinese
+
+For Chat user-facing pages and answers, the rendered answer SHALL be Chinese. If the Executor emits JSON, either:
+
+- `user_facing_answer` is returned to the user after verifier routing, or
+- ChatService renders a Chinese answer from the structured contract.
+
+The raw machine contract may remain visible in trace/debug views, but the normal user answer should not become an English/JSON-only artifact.
+
+Rationale: this aligns with current UI/product language requirements while keeping machine-checkable evidence.
+
+## Risks / Trade-offs
+
+- [Risk] LLM may emit malformed JSON. Mitigation: parse-status fallback and verifier natural-language fallback.
+- [Risk] Executor may put unsupported facts in `user_facing_answer` but omit them from `claims`. Mitigation: Verifier scans `user_facing_answer` for extra confirmed-sounding facts.
+- [Risk] Evidence excerpts may be fabricated. Mitigation: Verifier checks binding ids against `tool_trace_summary` and treats missing refs as no evidence.
+- [Risk] More verbose output increases tokens. Mitigation: keep excerpts bounded and put detailed raw evidence only in tool traces.
+- [Risk] Prompt-only enforcement is soft. Mitigation: add focused tests/eval fixtures and later consider code-level schema validation.
+
+## Migration Plan
+
+1. Update `chat-executor-prompt.md` with the evidence-attribution JSON contract.
+2. Add parsing in Chat runtime for Executor output:
+   - valid JSON -> preserve parsed `executor_structured_output`
+   - invalid JSON -> mark parse status and keep raw `executor_final_answer`
+3. Update verifier payload assembly to include `executor_structured_output` and parse status.
+4. Update `chat-verifier-prompt.md` to prefer structured claims and verify extra facts in `user_facing_answer`.
+5. Persist parsed or raw structured output in existing trace/evaluation snapshots without schema changes.
+6. Add focused tests and regression fixtures for unsupported confirmed claims.
+7. Validate OpenSpec and run targeted tests.
+
+## Open Questions
+
+- Should `user_facing_answer` be mandatory in Executor JSON, or should ChatService render it from structured fields?
+- Should malformed Executor JSON force `LOW_CONFID`, or should Verifier decide based on natural-language fallback alone?
+- Should `support_level` allow only `direct`, `indirect`, and `none`, or should it also include `contradicted` for Executor self-reporting?
diff --git a/openspec/changes/executor-evidence-output-contract/proposal.md b/openspec/changes/executor-evidence-output-contract/proposal.md
new file mode 100644
index 0000000..c68cff8
--- /dev/null
+++ b/openspec/changes/executor-evidence-output-contract/proposal.md
@@ -0,0 +1,42 @@
+# Proposal: executor-evidence-output-contract
+
+## Why
+
+Recent Chat diagnosis sessions frequently end as `LOW_CONFID` even though evidence tools were called successfully. The main failure mode is not missing tool execution; it is that Executor blends tool evidence, runbook/reference patterns, and model inference into one natural-language answer, then presents unsupported details as confirmed incident facts.
+
+Verifier currently receives `original_query`, `executor_final_answer`, `tool_trace_summary`, and optional `retry_context`. It can catch unsupported claims, but it must first infer facts from unstructured prose. That makes the quality gate reactive and noisy: unsupported claims are detected after the answer has already been shaped as a confident story.
+
+## What Changes
+
+- Update the Chat Executor prompt so its final output follows a strict evidence-attribution JSON contract.
+- Require confirmed claims to carry explicit evidence bindings and require unsupported items to be placed in `hypotheses`, `missing_info`, or `recommended_actions` instead of confirmed conclusions.
+- Extend the verifier input contract with a parsed or raw `executor_structured_output` field while preserving the existing `executor_final_answer` field for fallback compatibility.
+- Update the Chat Verifier prompt so it prefers Executor-provided structured claims over natural-language fact extraction.
+- Keep Verifier isolated from Planner/Executor intermediate reasoning; it still receives only the original query, Executor final output, structured claim contract, tool trace summary, and retry context.
+- Do not change evidence tool signatures, database schema, or the `Planner -> Executor -> Verifier` topology.
+
+## Capabilities
+
+### New Capabilities
+
+None.
+
+### Modified Capabilities
+
+- `chat-verifier-agent`: Chat verification now consumes an Executor evidence-attribution contract when available.
+
+## Impact
+
+- Affected prompts: `chat-executor-prompt.md`, `chat-verifier-prompt.md`.
+- Affected integration: `VerifierInputHook` or equivalent verifier payload assembly must include `executor_structured_output` when Executor returns valid structured JSON.
+- Affected parsing: `ChatService` may parse Executor output to separate machine contract from user-facing text, with fallback when parsing fails.
+- Affected tests/eval: prompt contract tests, verifier input assembly tests, and unsupported-claim regression fixtures.
+- No database schema change is required. Structured Executor output can be persisted in existing step output fields and verifier snapshots.
+
+## Out Of Scope
+
+- Loosening Verifier scoring or `PASS` criteria.
+- Raising `verifier.low-confidence-threshold` to hide unsupported claims.
+- Treating runbook, skill, or historical case text as current incident evidence unless it was returned as evidence for the current query and bound explicitly.
+- Adding a new verifier tool or allowing Verifier to perform retrieval.
+- Replacing the existing tool trace summary contract.
diff --git a/openspec/changes/executor-evidence-output-contract/specs/chat-verifier-agent/spec.md b/openspec/changes/executor-evidence-output-contract/specs/chat-verifier-agent/spec.md
new file mode 100644
index 0000000..94bc0dd
--- /dev/null
+++ b/openspec/changes/executor-evidence-output-contract/specs/chat-verifier-agent/spec.md
@@ -0,0 +1,95 @@
+## MODIFIED Requirements
+
+### Requirement: Verifier SHALL consume explicit verification inputs
+The Verifier SHALL receive explicit verification inputs rather than inferring them only from raw conversation history.
+
+#### Scenario: explicit input blocks available to Verifier
+- **WHEN** the Verifier starts
+- **THEN** the system SHALL provide `original_query`, `executor_final_answer`, and `tool_trace_summary` as explicit inputs
+- **AND** `retry_context` SHALL be provided on the second round only
+- **AND** when Executor returns a valid evidence-attribution contract, the system SHALL provide `executor_structured_output`
+- **AND** when Executor output parsing fails, the system SHALL provide an `executor_output_parse_status` that indicates the failure
+- **AND** message filtering MAY be used only to remove intermediate reasoning or unrelated noise
+
+#### Scenario: Verifier remains isolated from intermediate reasoning
+- **WHEN** `executor_structured_output` is added to the verifier input
+- **THEN** the input SHALL still exclude Planner reasoning and Executor intermediate reasoning
+- **AND** the input SHALL be limited to the original query, final Executor output, parsed Executor evidence contract, tool trace summary, and retry context
+
+### Requirement: Verifier SHALL fact-check Executor answers
+The system SHALL have a Verifier Agent that reads the Executor's answer and the tool call history, then produces a structured verdict.
+
+#### Scenario: Structured Executor claims are verified first
+- **WHEN** `executor_structured_output.claims` is present and valid
+- **THEN** Verifier SHALL verify each structured claim against `tool_trace_summary`
+- **AND** each claim's evidence bindings SHALL reference existing trace or invocation identifiers when those identifiers are available
+- **AND** a claim with fabricated or missing evidence references SHALL NOT be classified as `direct_evidence`
+
+#### Scenario: Extra confirmed-sounding answer facts are still checked
+- **WHEN** `executor_structured_output.user_facing_answer` contains confirmed-sounding facts that are absent from `executor_structured_output.claims`
+- **THEN** Verifier SHALL add those facts to `facts_checked`
+- **AND** unsupported extra facts SHALL lower the verdict according to the existing verdict matrix
+
+#### Scenario: Natural-language fallback remains available
+- **WHEN** Executor does not return parseable structured output
+- **THEN** Verifier SHALL fall back to extracting facts from `executor_final_answer`
+- **AND** the final verdict SHALL still follow the existing groundedness and evidence classification rules
+
+## ADDED Requirements
+
+### Requirement: Executor SHALL output an evidence-attribution contract
+The Chat Executor SHALL produce a machine-checkable final output that separates confirmed claims from hypotheses, recommendations, and missing information.
+
+#### Scenario: Executor final output contains required top-level fields
+- **WHEN** Executor completes a Chat diagnosis step
+- **THEN** its final output SHALL contain `answer_version`, `diagnosis_summary`, `claims`, `hypotheses`, `recommended_actions`, `missing_info`, and `user_facing_answer`
+- **AND** the output SHOULD be parseable as one JSON object without Markdown fences
+
+#### Scenario: Confirmed claims carry evidence bindings
+- **WHEN** Executor emits an item under `claims`
+- **THEN** the item SHALL include `claim_id`, `claim_type`, `claim_text`, `support_level`, and `evidence_bindings`
+- **AND** `support_level` SHALL be one of `direct`, `indirect`, or `none`
+- **AND** claims with `support_level=direct` or `support_level=indirect` SHALL include at least one evidence binding
+
+#### Scenario: Evidence bindings support multiple tool types
+- **WHEN** Executor binds evidence to a claim
+- **THEN** each binding SHALL include `source_type`, `source_id`, `tool_name`, `source_invocation_ids`, and `evidence_excerpt`
+- **AND** the binding SHALL be able to reference `lookup_knowledge`, `query_logs`, `query_metrics`, or other evidence-bearing tool traces
+- **AND** the binding SHALL NOT rely only on a RAG-specific `chunk_id`
+
+#### Scenario: Unsupported conclusions are not confirmed claims
+- **WHEN** a possible root cause, detail, or remediation lacks current-session tool evidence
+- **THEN** Executor SHALL place it under `hypotheses`, `recommended_actions`, or `missing_info`
+- **AND** Executor SHALL NOT present it as a confirmed claim
+
+#### Scenario: Runbook and skill guidance do not become incident facts
+- **WHEN** Executor uses runbook, skill, or historical-case guidance
+- **THEN** the guidance MAY influence `recommended_actions`
+- **AND** the guidance SHALL NOT be emitted as a current incident fact unless current-session tool evidence supports it
+
+### Requirement: User-facing Chat answers SHALL remain readable Chinese
+The system SHALL preserve a readable Chinese answer for normal Chat users even when Executor emits a machine-checkable contract.
+
+#### Scenario: User-facing answer is available
+- **WHEN** Executor emits structured output
+- **THEN** `user_facing_answer` SHALL be written in Chinese
+- **AND** it SHALL be consistent with the confirmed claims, hypotheses, recommended actions, and missing information in the same JSON object
+
+#### Scenario: Machine contract remains available for trace inspection
+- **WHEN** the Chat trace or verifier evaluation is inspected
+- **THEN** the structured Executor contract MAY be shown for debugging or audit
+- **AND** normal user output SHALL use the existing verifier-routed display path rather than exposing raw JSON by default
+
+### Requirement: Structured Executor output SHALL degrade safely
+The system SHALL tolerate malformed or absent structured Executor output without crashing the Chat flow.
+
+#### Scenario: Malformed Executor JSON is captured
+- **WHEN** Executor returns malformed JSON or text outside the expected contract
+- **THEN** Chat runtime SHALL preserve the raw `executor_final_answer`
+- **AND** it SHALL mark `executor_output_parse_status` as failed
+- **AND** Verifier SHALL use natural-language fallback behavior
+
+#### Scenario: Structured parse failure remains observable
+- **WHEN** Executor output parsing fails
+- **THEN** the verifier evaluation or trace snapshot SHALL make the parse failure visible
+- **AND** the failure SHALL NOT be silently treated as a successful evidence-attribution contract
diff --git a/openspec/changes/executor-evidence-output-contract/tasks.md b/openspec/changes/executor-evidence-output-contract/tasks.md
new file mode 100644
index 0000000..392490d
--- /dev/null
+++ b/openspec/changes/executor-evidence-output-contract/tasks.md
@@ -0,0 +1,31 @@
+## 1. Executor Contract
+
+- [x] 1.1 Update `chat-executor-prompt.md` with the evidence-attribution JSON contract.
+- [x] 1.2 Require confirmed claims, hypotheses, recommended actions, missing information, and Chinese `user_facing_answer`.
+- [x] 1.3 Add prompt-level constraints that runbook/skill/history guidance cannot become current incident facts without current-session evidence.
+
+## 2. Runtime Parsing And Verifier Input
+
+- [x] 2.1 Parse Executor final output into `executor_structured_output` when it is valid JSON.
+- [x] 2.2 Add `executor_output_parse_status` for valid, missing, and malformed outputs.
+- [x] 2.3 Pass `executor_structured_output` and parse status into the verifier payload while preserving existing `executor_final_answer`.
+- [x] 2.4 Persist or expose the structured output through existing trace/evaluation snapshots without a schema change.
+
+## 3. Verifier Prompt
+
+- [x] 3.1 Update `chat-verifier-prompt.md` to verify structured claims before natural-language extraction.
+- [x] 3.2 Add a verifier rule to scan `user_facing_answer` for extra confirmed-sounding facts not present in structured `claims`.
+- [x] 3.3 Keep the existing natural-language fallback for malformed or absent structured output.
+
+## 4. Tests And Evaluation
+
+- [x] 4.1 Add focused tests for Executor output parsing and parse-status fallback.
+- [x] 4.2 Add focused tests for verifier payload assembly with structured Executor output.
+- [x] 4.3 Add prompt/fixture regression coverage for unsupported claims being placed outside confirmed `claims`.
+- [x] 4.4 Add or update eval fixture checks that confirmed claims must have evidence bindings.
+
+## 5. Verification
+
+- [x] 5.1 Run targeted unit tests for the parsing and verifier-input changes.
+- [x] 5.2 Run relevant Chat verifier/eval regression tests.
+- [x] 5.3 Run OpenSpec validation for `executor-evidence-output-contract`.
diff --git a/src/main/java/com/superbiz/agent/eval/DiagnosisTraceEvaluator.java b/src/main/java/com/superbiz/agent/eval/DiagnosisTraceEvaluator.java
index 77588f5..0abd070 100644
--- a/src/main/java/com/superbiz/agent/eval/DiagnosisTraceEvaluator.java
+++ b/src/main/java/com/superbiz/agent/eval/DiagnosisTraceEvaluator.java
@@ -101,6 +101,8 @@ public class DiagnosisTraceEvaluator {
             failedChecks.add("reject output does not use degraded template");
         }
 
+        failedChecks.addAll(validateExecutorStructuredOutput(trace));
+
         Integer toolCallCount = trace.getToolInvocations() == null ? 0 : trace.getToolInvocations().size();
         Integer durationMs = trace.getSession() == null ? null : trace.getSession().getTotalDurationMs();
 
@@ -174,6 +176,32 @@ public class DiagnosisTraceEvaluator {
         return value == null ? null : String.valueOf(value);
     }
 
+    private List<String> validateExecutorStructuredOutput(DiagnosisTraceResponse trace) {
+        Object structuredOutput = nestedValue(trace, "verifier_evaluation", "executor_structured_output");
+        if (!(structuredOutput instanceof Map<?, ?> output)) {
+            return List.of();
+        }
+        Object claims = output.get("claims");
+        if (!(claims instanceof List<?> claimList)) {
+            return List.of("executor structured output missing claims array");
+        }
+
+        List<String> failedChecks = new ArrayList<>();
+        for (Object item : claimList) {
+            if (!(item instanceof Map<?, ?> claim)) {
+                failedChecks.add("executor structured claim is not an object");
+                continue;
+            }
+            Object claimIdValue = claim.get("claim_id");
+            String claimId = claimIdValue == null ? "unknown" : String.valueOf(claimIdValue);
+            Object bindings = claim.get("evidence_bindings");
+            if (!(bindings instanceof List<?> bindingList) || bindingList.isEmpty()) {
+                failedChecks.add("executor confirmed claim missing evidence bindings: " + claimId);
+            }
+        }
+        return failedChecks;
+    }
+
     private Object nestedValue(DiagnosisTraceResponse trace, String firstKey, String secondKey) {
         if (trace.getSession() == null || trace.getSession().getSelfEvaluation() == null) {
             return null;
diff --git a/src/main/java/com/superbiz/agent/hook/VerifierInputHook.java b/src/main/java/com/superbiz/agent/hook/VerifierInputHook.java
index 6e599be..4a9fe83 100644
--- a/src/main/java/com/superbiz/agent/hook/VerifierInputHook.java
+++ b/src/main/java/com/superbiz/agent/hook/VerifierInputHook.java
@@ -5,6 +5,8 @@ import com.alibaba.cloud.ai.graph.agent.hook.HookPosition;
 import com.alibaba.cloud.ai.graph.agent.hook.HookPositions;
 import com.alibaba.cloud.ai.graph.agent.hook.messages.AgentCommand;
 import com.alibaba.cloud.ai.graph.agent.hook.messages.MessagesModelHook;
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.superbiz.agent.service.ToolTraceSummaryService;
 import com.superbiz.agent.util.SessionContextHolder;
@@ -27,6 +29,8 @@ public class VerifierInputHook extends MessagesModelHook {
 
     private final ToolTraceSummaryService toolTraceSummaryService;
     private final ObjectMapper objectMapper = new ObjectMapper();
+    private static final TypeReference<Map<String, Object>> MAP_TYPE = new TypeReference<>() {
+    };
 
     public VerifierInputHook(ToolTraceSummaryService toolTraceSummaryService) {
         this.toolTraceSummaryService = toolTraceSummaryService;
@@ -48,6 +52,10 @@ public class VerifierInputHook extends MessagesModelHook {
                 executorFinalAnswer = extractLastAssistantText(previousMessages);
             }
 
+            ExecutorOutputParseResult parseResult = parseExecutorOutput(executorFinalAnswer);
+            VerifierContextHolder.setExecutorStructuredOutput(parseResult.structuredOutput());
+            VerifierContextHolder.setExecutorOutputParseStatus(parseResult.status());
+
             List<Map<String, Object>> toolTraceSummary =
                     toolTraceSummaryService.buildVerifierTraceSummary(sessionId, executorFinalAnswer);
             VerifierContextHolder.setToolTraceSummary(toolTraceSummary);
@@ -55,6 +63,8 @@ public class VerifierInputHook extends MessagesModelHook {
             Map<String, Object> verifierInput = new LinkedHashMap<>();
             verifierInput.put("original_query", VerifierContextHolder.getOriginalQuery());
             verifierInput.put("executor_final_answer", executorFinalAnswer);
+            verifierInput.put("executor_structured_output", parseResult.structuredOutput());
+            verifierInput.put("executor_output_parse_status", parseResult.status());
             verifierInput.put("tool_trace_summary", toolTraceSummary);
             verifierInput.put("retry_context", VerifierContextHolder.getRetryContext());
 
@@ -66,6 +76,59 @@ public class VerifierInputHook extends MessagesModelHook {
         }
     }
 
+    private ExecutorOutputParseResult parseExecutorOutput(String executorFinalAnswer) {
+        if (executorFinalAnswer == null || executorFinalAnswer.isBlank()) {
+            return new ExecutorOutputParseResult(null, status("missing", "executor_final_answer is blank"));
+        }
+
+        String sanitized = sanitizeJsonPayload(executorFinalAnswer);
+        if (!looksJsonLike(sanitized)) {
+            return new ExecutorOutputParseResult(null, status("missing", "executor output is not JSON"));
+        }
+
+        try {
+            JsonNode root = objectMapper.readTree(sanitized);
+            if (!root.isObject() || !root.path("claims").isArray()) {
+                return new ExecutorOutputParseResult(null, status("malformed",
+                        "executor output JSON does not match evidence-attribution contract"));
+            }
+            Map<String, Object> structuredOutput = objectMapper.convertValue(root, MAP_TYPE);
+            return new ExecutorOutputParseResult(structuredOutput, status("valid", "parsed executor evidence contract"));
+        } catch (Exception e) {
+            log.debug("Failed to parse executor structured output", e);
+            return new ExecutorOutputParseResult(null, status("malformed", e.getMessage()));
+        }
+    }
+
+    private String sanitizeJsonPayload(String raw) {
+        String trimmed = raw.trim();
+        int fenceStart = trimmed.indexOf("```");
+        if (fenceStart >= 0) {
+            int firstNewline = trimmed.indexOf('\n', fenceStart);
+            int lastFence = trimmed.indexOf("```", firstNewline + 1);
+            if (firstNewline >= 0 && lastFence > firstNewline) {
+                return trimmed.substring(firstNewline + 1, lastFence).trim();
+            }
+        }
+        int objectStart = trimmed.indexOf('{');
+        int objectEnd = trimmed.lastIndexOf('}');
+        if (objectStart >= 0 && objectEnd > objectStart) {
+            return trimmed.substring(objectStart, objectEnd + 1).trim();
+        }
+        return trimmed;
+    }
+
+    private boolean looksJsonLike(String text) {
+        return text.startsWith("{") && text.endsWith("}");
+    }
+
+    private Map<String, Object> status(String status, String detail) {
+        Map<String, Object> result = new LinkedHashMap<>();
+        result.put("status", status);
+        result.put("detail", detail == null ? "" : detail);
+        return result;
+    }
+
     private String extractLastAssistantText(List<Message> previousMessages) {
         for (int i = previousMessages.size() - 1; i >= 0; i--) {
             if (previousMessages.get(i) instanceof AssistantMessage assistantMessage) {
@@ -102,4 +165,10 @@ public class VerifierInputHook extends MessagesModelHook {
         }
         return message.toString();
     }
+
+    private record ExecutorOutputParseResult(
+            Map<String, Object> structuredOutput,
+            Map<String, Object> status
+    ) {
+    }
 }
diff --git a/src/main/java/com/superbiz/agent/service/ChatService.java b/src/main/java/com/superbiz/agent/service/ChatService.java
index 83f7055..d0e2b9f 100644
--- a/src/main/java/com/superbiz/agent/service/ChatService.java
+++ b/src/main/java/com/superbiz/agent/service/ChatService.java
@@ -444,7 +444,8 @@ public class ChatService {
                 }
 
                 if ("PASS".equals(finalDecision.verdict())) {
-                    answer = answer == null || answer.isBlank() ? "抱歉，多 Agent 分析未能生成有效结论。" : answer;
+                    answer = extractUserFacingAnswer(answer)
+                            .orElse(answer == null || answer.isBlank() ? "抱歉，多 Agent 分析未能生成有效结论。" : answer);
                     persistVerifierEvaluation(session, finalDecision, round);
                     break;
                 }
@@ -744,6 +745,10 @@ public class ChatService {
         verifierEvaluation.put("rationale", decision.rationale());
         verifierEvaluation.put("round", round);
         verifierEvaluation.put("traceability_version", "v1");
+        verifierEvaluation.put("executor_output_parse_status",
+                Optional.ofNullable(VerifierContextHolder.getExecutorOutputParseStatus())
+                        .orElse(Map.of("status", "missing", "detail", "executor parse status unavailable")));
+        verifierEvaluation.put("executor_structured_output", VerifierContextHolder.getExecutorStructuredOutput());
         verifierEvaluation.put("tool_trace_summary",
                 Optional.ofNullable(VerifierContextHolder.getToolTraceSummary()).orElse(List.of()));
 
@@ -795,6 +800,22 @@ public class ChatService {
         return output.toString();
     }
 
+    private Optional<String> extractUserFacingAnswer(String executorAnswer) {
+        if (executorAnswer == null || executorAnswer.isBlank()) {
+            return Optional.empty();
+        }
+        try {
+            JsonNode root = objectMapper.readTree(sanitizeJsonPayload(executorAnswer));
+            String userFacingAnswer = root.path("user_facing_answer").asText("");
+            if (!userFacingAnswer.isBlank()) {
+                return Optional.of(userFacingAnswer);
+            }
+        } catch (Exception e) {
+            logger.debug("Executor answer is not structured JSON, keep raw answer");
+        }
+        return Optional.empty();
+    }
+
     private String buildDegradedOutput(VerifierDecision decision) {
         StringBuilder output = new StringBuilder(DEGRADED_PREFIX);
 
diff --git a/src/main/java/com/superbiz/agent/util/VerifierContextHolder.java b/src/main/java/com/superbiz/agent/util/VerifierContextHolder.java
index 3bad0a4..d6fab9b 100644
--- a/src/main/java/com/superbiz/agent/util/VerifierContextHolder.java
+++ b/src/main/java/com/superbiz/agent/util/VerifierContextHolder.java
@@ -11,6 +11,8 @@ public final class VerifierContextHolder {
     private static final ThreadLocal<String> ORIGINAL_QUERY = new ThreadLocal<>();
     private static final ThreadLocal<String> RETRY_CONTEXT = new ThreadLocal<>();
     private static final ThreadLocal<String> EXECUTOR_FINAL_ANSWER = new ThreadLocal<>();
+    private static final ThreadLocal<Map<String, Object>> EXECUTOR_STRUCTURED_OUTPUT = new ThreadLocal<>();
+    private static final ThreadLocal<Map<String, Object>> EXECUTOR_OUTPUT_PARSE_STATUS = new ThreadLocal<>();
     private static final ThreadLocal<List<Map<String, Object>>> TOOL_TRACE_SUMMARY = new ThreadLocal<>();
 
     private VerifierContextHolder() {
@@ -40,6 +42,22 @@ public final class VerifierContextHolder {
         return EXECUTOR_FINAL_ANSWER.get();
     }
 
+    public static void setExecutorStructuredOutput(Map<String, Object> executorStructuredOutput) {
+        EXECUTOR_STRUCTURED_OUTPUT.set(executorStructuredOutput);
+    }
+
+    public static Map<String, Object> getExecutorStructuredOutput() {
+        return EXECUTOR_STRUCTURED_OUTPUT.get();
+    }
+
+    public static void setExecutorOutputParseStatus(Map<String, Object> executorOutputParseStatus) {
+        EXECUTOR_OUTPUT_PARSE_STATUS.set(executorOutputParseStatus);
+    }
+
+    public static Map<String, Object> getExecutorOutputParseStatus() {
+        return EXECUTOR_OUTPUT_PARSE_STATUS.get();
+    }
+
     public static void setToolTraceSummary(List<Map<String, Object>> toolTraceSummary) {
         TOOL_TRACE_SUMMARY.set(toolTraceSummary);
     }
@@ -52,6 +70,8 @@ public final class VerifierContextHolder {
         ORIGINAL_QUERY.remove();
         RETRY_CONTEXT.remove();
         EXECUTOR_FINAL_ANSWER.remove();
+        EXECUTOR_STRUCTURED_OUTPUT.remove();
+        EXECUTOR_OUTPUT_PARSE_STATUS.remove();
         TOOL_TRACE_SUMMARY.remove();
     }
 }
diff --git a/src/main/resources/prompts/chat-executor-prompt.md b/src/main/resources/prompts/chat-executor-prompt.md
index e30f608..703bda0 100644
--- a/src/main/resources/prompts/chat-executor-prompt.md
+++ b/src/main/resources/prompts/chat-executor-prompt.md
@@ -1,15 +1,17 @@
 你是任务执行器。执行 Planner 分配给你的具体步骤，并及时反馈结果。
 
 ## 职责
-- 按步骤执行具体的查询任务
-- 需要外部信息时调用工具，但须遵守下方的检索约束
-- 不要凭记忆回答，必须基于工具返回的真实数据
-- 执行完成后，综合所有结果给出完整的答案
+- 按步骤执行具体的查询任务。
+- 需要外部信息时调用工具，但必须遵守下方的检索约束。
+- 严禁凭记忆回答，必须基于本轮工具返回的真实数据。
+- 执行完成后，输出严格的证据归因 JSON，供 Verifier 校验。
 
 ## 规则
-- 按顺序执行，不可跳过步骤
-- 不要凭记忆回答，必须基于工具返回的真实数据
-- 执行完成后，综合所有结果给出完整的答案
+- 按顺序执行，不可跳过步骤。
+- 所有事实性结论必须来自本轮 evidence tools 的返回。
+- runbook、skill、历史案例、知识库中的通用模式只能作为排查指导或建议动作，不能直接写成本次事故的已确认事实。
+- 如果检索内容不足以支撑结论，必须显式声明证据不足，严禁补全事故故事。
+- 不要使用“通常情况下”“根据经验”“很可能已经发生”等无证据推断词来伪装事实。
 
 ## 检索约束
 
@@ -20,22 +22,99 @@
 
 ### 2. 重复了该怎么办
 如果当前想检索的内容与【已检索上下文】语义相似：
-- 禁止换关键词重新检索
-- 直接基于已有事实回答
+- 禁止换关键词重新检索。
+- 直接基于已有事实回答。
 - 如果信息不足，先明确指出缺少什么具体维度
-  （如："缺少 HikariCP 具体配置参数"、"缺少连接池耗尽的日志样例"），
-  再针对该维度进行一次定向补充检索——而非盲目换词重查
+  （如：“缺少 HikariCP 具体配置参数”、“缺少连接池耗尽的日志样例”），
+  再针对该维度进行一次定向补充检索，而非盲目换词重查。
 
-### 3. 合法出口：允许信息不全时给出结论
-如果你认为已有信息足以回答核心问题，即使细节不全，
-也请直接给出结论并说明局限性（如："基于已有信息，连接池配置建议如下，
-但具体参数值需结合实际负载调整"）。
-**不查全不会被追责，重复检索才会被惩罚。**
+### 3. 合法出口：允许信息不全时给出有限结论
+如果已有信息足以回答核心问题，即使细节不全，也可以给出有限结论。
+但你只能把有证据支撑的内容放入 `claims`。
+缺失的细节必须写入 `missing_info`，可疑但未证实的方向必须写入 `hypotheses`。
+**不查全不会被追责，重复检索或编造细节才会被惩罚。**
 
 ### 4. 利用质量信号判断
-- relevanceLevel=PRECISE → 信息精准，直接使用，不再检索
-- relevanceLevel=HIGHLY_RELEVANT + 域已在 retrievedDomainsThisSession → 禁止再次调用
-- relevanceLevel=REFERENCE → 先指出缺什么维度，再定向补充一次
-- completenessHint 是知识库给你的天花板信号，信任它
-- lookup_knowledge 的事实证据以 evidenceBlocks 和 contextPack.packedText 为准，不要假设 L0 hint 本身就是事实证据
-- retrievalTrace 只用于理解检索路径和降级原因，不能单独作为诊断事实
+- relevanceLevel=PRECISE → 信息精准，直接使用，不再检索。
+- relevanceLevel=HIGHLY_RELEVANT + 域已在 retrievedDomainsThisSession → 禁止再次调用。
+- relevanceLevel=REFERENCE → 先指出缺什么维度，再定向补充一次。
+- completenessHint 是知识库给你的天花板信号，信任它。
+- lookup_knowledge 的事实证据以 evidenceBlocks 和 contextPack.packedText 为准，不要假设 L0 hint 本身就是事实证据。
+- retrievalTrace 只用于理解检索路径和降级原因，不能单独作为诊断事实。
+
+## 证据归因要求
+
+### confirmed claims
+`claims` 只允许放已证实或有明确间接支撑的事实断言。
+每条 claim 必须带证据绑定。
+
+支持等级：
+- `direct`：工具返回中有直接事实。
+- `indirect`：工具返回可支撑方向，但没有直接陈述完整结论。
+- `none`：不能放入 `claims`，应放入 `hypotheses`、`recommended_actions` 或 `missing_info`。
+
+### hypotheses
+`hypotheses` 用来放合理怀疑但未被工具证实的方向。
+例如：工具只显示连接池耗尽，但没有泄漏日志，则“可能存在连接泄漏”只能是 hypothesis。
+
+### recommended_actions
+`recommended_actions` 用来放下一步排查或修复动作。
+建议可以来自 runbook/skill，但必须说明 reason，不能写成“已确认根因”。
+
+### missing_info
+`missing_info` 用来列出无法确认结论所缺少的具体证据。
+
+## 最终输出格式（严格契约）
+
+你必须输出且只能输出一个 JSON 对象，不要输出 Markdown，不要输出代码块，不要输出 JSON 之外的解释文字。
+所有用户可读内容必须使用中文。
+
+```json
+{
+  "answer_version": "executor_evidence_v1",
+  "diagnosis_summary": "1-2句话总结，仅包含有证据支撑的事实和证据边界",
+  "claims": [
+    {
+      "claim_id": "claim-1",
+      "claim_type": "root_cause",
+      "claim_text": "事实断言或有限结论",
+      "support_level": "direct",
+      "evidence_bindings": [
+        {
+          "source_type": "tool_trace",
+          "source_id": "工具返回中的 evidence block id、trace_ref 或可定位标识",
+          "tool_name": "lookup_knowledge/query_logs/query_metrics/read_skill 等",
+          "source_invocation_ids": [],
+          "evidence_excerpt": "从工具返回中摘取的原话、指标值、日志片段或关键数据"
+        }
+      ]
+    }
+  ],
+  "hypotheses": [
+    {
+      "hypothesis_text": "未被证实但值得排查的方向",
+      "basis": "它基于哪些已知证据或为什么只是推测",
+      "needed_evidence": ["需要补充的证据"]
+    }
+  ],
+  "recommended_actions": [
+    {
+      "action_text": "建议动作",
+      "reason": "为什么建议做这个动作",
+      "evidence_bindings": []
+    }
+  ],
+  "missing_info": [
+    "导致无法确认完整根因的证据缺口"
+  ],
+  "user_facing_answer": "面向用户的中文回答。必须与 claims/hypotheses/recommended_actions/missing_info 一致，不得额外加入未绑定证据的确认式事实。"
+}
+```
+
+## 输出校验
+- `claims[*].support_level` 只能是 `direct` 或 `indirect`。
+- `claims[*].evidence_bindings` 不能为空。
+- `evidence_excerpt` 必须来自工具返回，不允许编造。
+- 如果没有任何可确认事实，`claims` 返回空数组，并在 `missing_info` 说明缺少什么。
+- `user_facing_answer` 不得出现 `claims` 中没有、且又被写成确认结论的事实。
+- 不要把其它服务、其它历史案例、其它会话的事实迁移为当前会话事实。
diff --git a/src/main/resources/prompts/chat-verifier-prompt.md b/src/main/resources/prompts/chat-verifier-prompt.md
index 8a5c9cd..11891eb 100644
--- a/src/main/resources/prompts/chat-verifier-prompt.md
+++ b/src/main/resources/prompts/chat-verifier-prompt.md
@@ -10,6 +10,8 @@
 
 - `original_query`：用户原始问题
 - `executor_final_answer`：本轮 Executor 最终答案
+- `executor_structured_output`：如果 Executor 输出了合法证据归因 JSON，这里会提供解析后的对象。结构包含 `claims`、`hypotheses`、`recommended_actions`、`missing_info`、`user_facing_answer`
+- `executor_output_parse_status`：Executor 输出解析状态，包含 `status` 和 `detail`。`status` 可能是 `valid` / `missing` / `malformed`
 - `tool_trace_summary`：基于真实工具调用整理出的证据索引。每一项都带有：
   - `trace_ref`
   - `tool_name`
@@ -23,7 +25,18 @@
 ## 任务步骤
 
 ### 步骤一：提取关键事实
-优先提取并校验 `executor_final_answer` 里的全部实质性结论。关键事实至少包括：
+如果 `executor_output_parse_status.status="valid"` 且 `executor_structured_output.claims` 存在：
+- 优先逐条校验 `executor_structured_output.claims`
+- 每个 claim 至少形成一条 `facts_checked`
+- 必须检查 claim 的 `evidence_bindings` 是否能对应到 `tool_trace_summary` 中真实存在的 trace、tool 或 source_invocation_ids
+- 如果 claim 声称 direct/indirect 支撑，但 evidence binding 不存在、无法定位、或 excerpt 与工具摘要不匹配，不得判为 `direct_evidence`
+
+然后必须扫描 `executor_structured_output.user_facing_answer`：
+- 如果其中出现 confirmed-sounding facts（确认式事实、根因、指标值、错误码、服务名、修复结论）
+- 且这些事实没有出现在 `executor_structured_output.claims`
+- 必须额外加入 `facts_checked` 并按工具证据校验
+
+如果 structured output 缺失或 malformed，则回退到旧逻辑：提取并校验 `executor_final_answer` 里的全部实质性结论。关键事实至少包括：
 - 每一个根因结论
 - 每一个错误码、接口、组件归属或语义判断
 - 每一个明确的修复建议、参数建议、排查步骤
@@ -49,6 +62,15 @@
 - `no_evidence`
 - `contradicted`
 
+结构化 claim 的校验规则：
+- claim 有真实 evidence binding，且工具摘要直接包含该事实 → `direct_evidence`
+- claim 有真实 evidence binding，但工具摘要只能支持方向或背景 → `indirect_support`
+- claim 无法绑定真实 trace、invocation 或 excerpt → `no_evidence`
+- claim 与工具摘要冲突，或编造了不存在的关键实体、服务、错误码、指标值 → `contradicted`
+
+`hypotheses` 和 `missing_info` 默认不是 confirmed facts，不应因为它们承认缺证据而惩罚。
+但如果 `user_facing_answer` 把 hypothesis 写成确认结论，必须按 confirmed fact 校验。
+
 ### 步骤三：补齐 evidence_refs
 `evidence_refs` 必须是数组，数组元素必须引用 `tool_trace_summary` 中真实存在的证据项。每个元素包含：
 - `trace_ref`
diff --git a/src/test/java/com/superbiz/agent/eval/DiagnosisTraceEvaluatorTest.java b/src/test/java/com/superbiz/agent/eval/DiagnosisTraceEvaluatorTest.java
index 8a0c9a8..6d71520 100644
--- a/src/test/java/com/superbiz/agent/eval/DiagnosisTraceEvaluatorTest.java
+++ b/src/test/java/com/superbiz/agent/eval/DiagnosisTraceEvaluatorTest.java
@@ -73,6 +73,41 @@ class DiagnosisTraceEvaluatorTest {
         assertTrue(result.getFailedChecks().contains("reject output does not use degraded template"));
     }
 
+    @Test
+    void evaluateFailsWhenStructuredConfirmedClaimHasNoEvidenceBindings() {
+        DiagnosisEvalCase evalCase = DiagnosisEvalCase.builder()
+                .id("structured-claim-case")
+                .title("Structured claim case")
+                .expectedRootCauseKeywords(List.of())
+                .requiredEvidenceTools(List.of())
+                .allowedVerdicts(List.of("LOW_CONFID", "PASS"))
+                .build();
+        DiagnosisTraceResponse trace = DiagnosisTraceResponse.builder()
+                .session(DiagnosisTraceResponse.SessionTrace.builder()
+                        .answer("以下结论基于当前已获取证据，仍存在部分证据缺口，请谨慎参考。")
+                        .selfEvaluation(java.util.Map.of(
+                                "verifier_evaluation", java.util.Map.of(
+                                        "verdict", "LOW_CONFID",
+                                        "executor_structured_output", java.util.Map.of(
+                                                "claims", java.util.List.of(java.util.Map.of(
+                                                        "claim_id", "claim-unsupported",
+                                                        "claim_text", "OOM 导致连接泄漏",
+                                                        "support_level", "direct",
+                                                        "evidence_bindings", java.util.List.of()
+                                                ))
+                                        )
+                                )))
+                        .build())
+                .toolInvocations(List.of())
+                .build();
+
+        DiagnosisEvalResult result = evaluator.evaluate(evalCase, trace);
+
+        assertFalse(result.isPassed());
+        assertTrue(result.getFailedChecks().contains(
+                "executor confirmed claim missing evidence bindings: claim-unsupported"));
+    }
+
     @Test
     void reportWriterOutputsJsonAndMarkdown(@TempDir Path tempDir) throws Exception {
         DiagnosisEvalReport report = evaluator.evaluate(readCases(), Path.of("mvp/eval/fixtures"));
diff --git a/src/test/java/com/superbiz/agent/hook/VerifierInputHookTest.java b/src/test/java/com/superbiz/agent/hook/VerifierInputHookTest.java
new file mode 100644
index 0000000..c4b20e3
--- /dev/null
+++ b/src/test/java/com/superbiz/agent/hook/VerifierInputHookTest.java
@@ -0,0 +1,181 @@
+package com.superbiz.agent.hook;
+
+import com.alibaba.cloud.ai.graph.RunnableConfig;
+import com.alibaba.cloud.ai.graph.agent.hook.messages.AgentCommand;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.superbiz.agent.service.ToolTraceSummaryService;
+import com.superbiz.agent.util.VerifierContextHolder;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.ai.chat.messages.AssistantMessage;
+import org.springframework.ai.chat.messages.Message;
+import org.springframework.ai.chat.messages.UserMessage;
+
+import java.util.List;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+class VerifierInputHookTest {
+
+    private final ObjectMapper objectMapper = new ObjectMapper();
+
+    @AfterEach
+    void tearDown() {
+        VerifierContextHolder.clear();
+    }
+
+    @Test
+    void beforeModelAddsStructuredExecutorOutputWhenJsonContractIsValid() throws Exception {
+        ToolTraceSummaryService traceSummaryService = mock(ToolTraceSummaryService.class);
+        when(traceSummaryService.buildVerifierTraceSummary(anyString(), anyString())).thenReturn(List.of(
+                Map.of("trace_ref", "trace-1", "tool_name", "query_metrics")
+        ));
+        VerifierInputHook hook = new VerifierInputHook(traceSummaryService);
+        VerifierContextHolder.setOriginalQuery("分析 MySQL 连接池耗尽");
+
+        String executorOutput = """
+                {
+                  "answer_version": "executor_evidence_v1",
+                  "diagnosis_summary": "连接池已满，但缺少泄漏证据。",
+                  "claims": [
+                    {
+                      "claim_id": "claim-1",
+                      "claim_type": "symptom",
+                      "claim_text": "连接池 active 达到上限",
+                      "support_level": "direct",
+                      "evidence_bindings": [
+                        {
+                          "source_type": "tool_trace",
+                          "source_id": "trace-1",
+                          "tool_name": "query_metrics",
+                          "source_invocation_ids": [101],
+                          "evidence_excerpt": "active=50 max=50"
+                        }
+                      ]
+                    }
+                  ],
+                  "hypotheses": [],
+                  "recommended_actions": [],
+                  "missing_info": ["缺少泄漏检测日志"],
+                  "user_facing_answer": "已确认连接池 active 达到上限。"
+                }
+                """;
+
+        AgentCommand command = hook.beforeModel(
+                List.of(new AssistantMessage(executorOutput)),
+                RunnableConfig.builder().addMetadata("sessionId", "structured-session").build()
+        );
+
+        JsonNode payload = readPayload(command);
+        assertEquals("valid", payload.path("executor_output_parse_status").path("status").asText());
+        assertEquals("executor_evidence_v1",
+                payload.path("executor_structured_output").path("answer_version").asText());
+        assertEquals("连接池 active 达到上限",
+                payload.path("executor_structured_output").path("claims").get(0).path("claim_text").asText());
+        assertNotNull(VerifierContextHolder.getExecutorStructuredOutput());
+        assertEquals("valid", VerifierContextHolder.getExecutorOutputParseStatus().get("status"));
+    }
+
+    @Test
+    void beforeModelExtractsStructuredOutputFromPrefixedJsonFence() throws Exception {
+        ToolTraceSummaryService traceSummaryService = mock(ToolTraceSummaryService.class);
+        when(traceSummaryService.buildVerifierTraceSummary(anyString(), anyString())).thenReturn(List.of());
+        VerifierInputHook hook = new VerifierInputHook(traceSummaryService);
+
+        String executorOutput = """
+                现在我已经收集了足够的数据，最终输出如下。
+
+                ```json
+                {
+                  "answer_version": "executor_evidence_v1",
+                  "diagnosis_summary": "已确认连接池 active 达到上限。",
+                  "claims": [
+                    {
+                      "claim_id": "claim-1",
+                      "claim_type": "symptom",
+                      "claim_text": "连接池 active 达到上限",
+                      "support_level": "direct",
+                      "evidence_bindings": [
+                        {
+                          "source_type": "tool_trace",
+                          "source_id": "trace-1",
+                          "tool_name": "query_metrics",
+                          "source_invocation_ids": [101],
+                          "evidence_excerpt": "active=50 max=50"
+                        }
+                      ]
+                    }
+                  ],
+                  "hypotheses": [],
+                  "recommended_actions": [],
+                  "missing_info": [],
+                  "user_facing_answer": "已确认连接池 active 达到上限。"
+                }
+                ```
+                """;
+
+        AgentCommand command = hook.beforeModel(
+                List.of(new AssistantMessage(executorOutput)),
+                RunnableConfig.builder().addMetadata("sessionId", "fenced-session").build()
+        );
+
+        JsonNode payload = readPayload(command);
+        assertEquals("valid", payload.path("executor_output_parse_status").path("status").asText());
+        assertEquals("claim-1",
+                payload.path("executor_structured_output").path("claims").get(0).path("claim_id").asText());
+    }
+
+    @Test
+    void beforeModelMarksMalformedJsonAndKeepsRawAnswerFallback() throws Exception {
+        ToolTraceSummaryService traceSummaryService = mock(ToolTraceSummaryService.class);
+        when(traceSummaryService.buildVerifierTraceSummary(anyString(), anyString())).thenReturn(List.of());
+        VerifierInputHook hook = new VerifierInputHook(traceSummaryService);
+
+        AgentCommand command = hook.beforeModel(
+                List.of(new AssistantMessage("{\"diagnosis_summary\":\"缺少 claims\"}")),
+                RunnableConfig.builder().addMetadata("sessionId", "malformed-session").build()
+        );
+
+        JsonNode payload = readPayload(command);
+        assertEquals("malformed", payload.path("executor_output_parse_status").path("status").asText());
+        assertTrue(payload.path("executor_structured_output").isNull());
+        assertEquals("{\"diagnosis_summary\":\"缺少 claims\"}", payload.path("executor_final_answer").asText());
+        assertEquals("malformed", VerifierContextHolder.getExecutorOutputParseStatus().get("status"));
+    }
+
+    @Test
+    void beforeModelMarksPlainTextAsMissingStructuredOutput() throws Exception {
+        ToolTraceSummaryService traceSummaryService = mock(ToolTraceSummaryService.class);
+        when(traceSummaryService.buildVerifierTraceSummary(anyString(), anyString())).thenReturn(List.of());
+        VerifierInputHook hook = new VerifierInputHook(traceSummaryService);
+
+        AgentCommand command = hook.beforeModel(
+                List.of(new AssistantMessage("普通自然语言答案")),
+                RunnableConfig.builder().addMetadata("sessionId", "plain-session").build()
+        );
+
+        JsonNode payload = readPayload(command);
+        assertEquals("missing", payload.path("executor_output_parse_status").path("status").asText());
+        assertTrue(payload.path("executor_structured_output").isNull());
+        assertFalse(payload.path("executor_final_answer").asText().isBlank());
+    }
+
+    private JsonNode readPayload(AgentCommand command) throws Exception {
+        var field = AgentCommand.class.getDeclaredField("messages");
+        field.setAccessible(true);
+        @SuppressWarnings("unchecked")
+        List<Message> messages = (List<Message>) field.get(command);
+        assertEquals(1, messages.size());
+        Message message = messages.get(0);
+        assertTrue(message instanceof UserMessage);
+        return objectMapper.readTree(((UserMessage) message).getText());
+    }
+}
diff --git a/src/test/java/com/superbiz/agent/service/ChatServiceSequentialAgentTest.java b/src/test/java/com/superbiz/agent/service/ChatServiceSequentialAgentTest.java
index c5d25a3..2628363 100644
--- a/src/test/java/com/superbiz/agent/service/ChatServiceSequentialAgentTest.java
+++ b/src/test/java/com/superbiz/agent/service/ChatServiceSequentialAgentTest.java
@@ -226,6 +226,53 @@ class ChatServiceSequentialAgentTest {
         assertTrue(chatModel.sawVerifierPrompt);
     }
 
+    @Test
+    void verifierReceivesStructuredExecutorPayloadFields() throws Exception {
+        ChatService chatService = createChatService();
+        ScriptedChatModel chatModel = new ScriptedChatModel();
+        chatModel.executorOutput = """
+                {
+                  "answer_version": "executor_evidence_v1",
+                  "diagnosis_summary": "已确认连接池 active 达到上限。",
+                  "claims": [
+                    {
+                      "claim_id": "claim-1",
+                      "claim_type": "symptom",
+                      "claim_text": "连接池 active 达到上限",
+                      "support_level": "direct",
+                      "evidence_bindings": [
+                        {
+                          "source_type": "tool_trace",
+                          "source_id": "trace-1",
+                          "tool_name": "query_metrics",
+                          "source_invocation_ids": [101],
+                          "evidence_excerpt": "active=50 max=50"
+                        }
+                      ]
+                    }
+                  ],
+                  "hypotheses": [],
+                  "recommended_actions": [],
+                  "missing_info": [],
+                  "user_facing_answer": "已确认连接池 active 达到上限。"
+                }
+                """;
+
+        ChatService.ChatResult result = chatService.executeChatComplex(
+                chatModel,
+                new ToolCallback[0],
+                "请分析 MySQL 连接池耗尽",
+                List.of(),
+                "sequential-structured-executor-session"
+        );
+
+        assertEquals("已确认连接池 active 达到上限。", result.answer());
+        assertTrue(chatModel.verifierPromptText.contains("\"executor_structured_output\""));
+        assertTrue(chatModel.verifierPromptText.contains("\"executor_output_parse_status\""));
+        assertTrue(chatModel.verifierPromptText.contains("\"status\" : \"valid\""));
+        assertTrue(chatModel.verifierPromptText.contains("连接池 active 达到上限"));
+    }
+
     @Test
     void buildMethodToolsArrayIncludesLogsAndMetricsWhenAvailable() {
         ChatService chatService = new ChatService();
@@ -353,6 +400,7 @@ class ChatServiceSequentialAgentTest {
         private String plannerPromptText = "";
         private String executorPromptText = "";
         private String verifierPromptText = "";
+        private String executorOutput = "EXECUTOR_FINAL_ANSWER";
         private boolean sawVerifierPrompt;
         private final java.util.List<String> verifierOutputs;
         private int verifierOutputIndex;
@@ -396,7 +444,7 @@ class ChatServiceSequentialAgentTest {
             } else if (promptText.contains("EXECUTOR_TEST_PROMPT")) {
                 agentCalls.add("chat_executor");
                 executorPromptText = promptText;
-                text = "EXECUTOR_FINAL_ANSWER";
+                text = executorOutput;
             } else if (promptText.contains("VERIFIER_TEST_PROMPT")) {
                 agentCalls.add("chat_verifier");
                 verifierPromptText = promptText;