## MODIFIED Requirements

### Requirement: Verifier SHALL fact-check Executor answers
The system SHALL have a Verifier Agent that reads only Gatekeeper-projected structured Executor claims and verified claim-local evidence, then produces a structured verdict based on claim derivability.

#### Scenario: PASS verdict when all claims have evidence
- **WHEN** all critical claims in `verified_executor_output.claims` have direct observation or reasonable inference support in `verified_evidence`
- **AND** at least one critical claim has direct observation
- **AND** no critical claim is contradicted, unsupported, external unknown, or overstated
- **AND** verdict ceiling is PASS
- **THEN** the Verifier MAY output model verdict="PASS" with groundedness_score ≥ 0.5

#### Scenario: LOW_CONFID verdict with partial evidence
- **WHEN** no critical claim contradicts verified evidence
- **AND** some critical claims are `unsupported`, `external_unknown`, or `overstated`
- **THEN** the Verifier SHALL output model verdict="LOW_CONFID"

#### Scenario: LOW_CONFID verdict with only inference support
- **WHEN** no critical claim contradicts verified evidence
- **AND** all critical claims are only `reasonable_inference`
- **THEN** the Verifier SHALL output model verdict="LOW_CONFID"

#### Scenario: REJECT verdict when claims contradict evidence
- **WHEN** any critical claim in `verified_executor_output.claims` contradicts verified evidence
- **OR** the claim fabricates a key entity, error code, or conclusion that does not exist in verified evidence
- **THEN** the Verifier SHALL output model verdict="REJECT"

#### Scenario: Verified structured claims are the only verification target
- **WHEN** `verified_executor_output.claims` is present
- **THEN** Verifier SHALL verify each structured claim against matching `verified_evidence` through `claim_checks`
- **AND** each claim's evidence references SHALL match existing claim/invocation/tool/path identifiers when available
- **AND** a claim without matching verified evidence SHALL NOT be classified as `direct_observation`
- **AND** Verifier SHALL NOT receive or add confirmed facts from raw Executor text

#### Scenario: Executor output is invalid
- **WHEN** Executor does not return a legal structured contract
- **THEN** the Graph SHALL route directly to pre-verification Fallback
- **AND** Verifier SHALL NOT execute or fabricate a diagnostic verdict

### Requirement: facts_checked SHALL use a fixed classification set
The system SHALL continue to expose compatibility `facts_checked` using its fixed verification classification set.

#### Scenario: claim checks are mapped to legacy facts
- **WHEN** Verifier output contains `claim_checks`
- **THEN** the shared Verifier protocol parser SHALL derive compatibility `facts_checked` when the model did not provide them
- **AND** `direct_observation` SHALL map to `direct_evidence`
- **AND** `reasonable_inference` and `overstated` SHALL map to `indirect_support`
- **AND** `unsupported` and `external_unknown` SHALL map to `no_evidence`
- **AND** `contradicted` SHALL map to `contradicted`

### Requirement: ChatService SHALL route based on Verifier verdict
The system SHALL use Diagnosis StateGraph conditional edges, rather than a ChatService outer loop, to route explicit Verifier execution status and effective verdict.

#### Scenario: PASS routes to Composer
- **WHEN** Verifier completes with effective verdict="PASS"
- **THEN** the Graph SHALL invoke Composer with filtered Verifier-allowed material
- **AND** the final user-facing answer SHALL NOT pass through raw Executor output
- **AND** the final user-facing answer SHALL NOT read Executor `user_facing_answer`

#### Scenario: LOW_CONFID does not qualify for evidence retry
- **WHEN** Verifier completes LOW_CONFID but ceiling is LOW_CONFID, no valid critical evidence gap exists, or evidence retry count is already one
- **THEN** the Graph SHALL route to Composer without another Planner cycle
- **AND** the final answer SHALL distinguish confirmed information, possible directions, and evidence gaps

#### Scenario: LOW_CONFID qualifies for evidence retry
- **WHEN** Verifier completes LOW_CONFID with ceiling PASS, at least one critical valid evidence gap, and evidence retry count zero
- **THEN** the Graph SHALL invoke one EVIDENCE_GAP_ONLY Planner cycle
- **AND** it SHALL NOT use groundedness threshold or a ChatService feature flag to decide the retry

#### Scenario: REJECT does not enter retry round
- **WHEN** Verifier completes with effective verdict="REJECT"
- **THEN** the Graph SHALL NOT start an evidence supplementation round
- **AND** it SHALL route to Composer-safe output

#### Scenario: REJECT produces bounded output
- **WHEN** effective verdict is REJECT
- **THEN** the system SHALL output a degraded result indicating current evidence cannot support a reliable conclusion
- **AND** it SHALL NOT pass through raw Executor answer
- **AND** it SHALL NOT include an unsupported root-cause conclusion

#### Scenario: Verifier execution fails
- **WHEN** Verifier exhausts technical retry or returns a non-retryable failure
- **THEN** the Graph SHALL route to pre-verification Fallback
- **AND** no execution status string SHALL be used as model or effective verdict

### Requirement: Verifier SHALL be observable
The Verifier execution, effective verdict, and downstream final-answer composition SHALL be persisted in the current Diagnosis Run self-evaluation container.

#### Scenario: claim checks written to self_evaluation
- **WHEN** a completed Verifier evaluation is persisted
- **THEN** `diagnosis_run.self_evaluation.verifier_evaluation` SHALL include `claim_checks`
- **AND** it SHALL continue to include compatibility `facts_checked`
- **AND** it SHALL include `verifier_status`, `model_verdict`, `effective_verdict`, `verdict`, `groundedness_score`, `rationale`, verified output/evidence, and Gatekeeper audit

#### Scenario: composer output written to self_evaluation
- **WHEN** final answer composition completes
- **THEN** `diagnosis_run.self_evaluation.verifier_evaluation` SHALL include compact `composer_output` when available
- **AND** handled Composer fallback SHALL remain observable through orchestration trace and status/reason fields
- **AND** existing claim/fact and Gatekeeper fields SHALL be preserved

#### Scenario: verdict written to self_evaluation
- **WHEN** Verifier completes
- **THEN** Graph result mapping SHALL write effective verdict under `diagnosis_run.self_evaluation.verifier_evaluation.verdict`
- **AND** existing `rule_evaluation` and `aiops_rule_evaluation` channels SHALL be preserved

#### Scenario: pre-verification fallback is persisted
- **WHEN** Graph reaches Fallback before Verifier completes
- **THEN** verifier evaluation SHALL include available status, Gatekeeper audit, failure reason, and Prompt audit
- **AND** it SHALL NOT fabricate `model_verdict` or `effective_verdict`

#### Scenario: gatekeeper result written to self_evaluation
- **WHEN** Graph result mapping persists available Gatekeeper state
- **THEN** `diagnosis_run.self_evaluation.verifier_evaluation` SHALL include `gatekeeper_result`
- **AND** the result SHALL retain status, severity, checked bindings, rules, failed rules, warnings, and errors when provided by Gatekeeper

#### Scenario: prompt audit written to verifier evaluation
- **WHEN** a complex Chat Graph result is persisted
- **THEN** the system SHALL include a `prompt_audit` object under `diagnosis_run.self_evaluation.verifier_evaluation`
- **AND** `prompt_audit.version` SHALL identify the Chat Prompt audit catalog version
- **AND** `prompt_audit.prompts` SHALL include Planner, Executor, Verifier, and Composer Prompt names and versions
- **AND** full Prompt text SHALL NOT be persisted

#### Scenario: prompt audit available on fallback paths
- **WHEN** Planner, Executor, Gatekeeper, Verifier, or Composer reaches a handled Fallback
- **THEN** the persisted verifier evaluation SHALL still include `prompt_audit`

#### Scenario: evaluation payload is inspected
- **WHEN** Graph verifier evaluation is persisted
- **THEN** it SHALL NOT contain raw Executor text or complete `tool_trace_summary`
- **AND** compatibility `executor_structured_output` SHALL contain at most the verified projection

### Requirement: Verifier SHALL consume explicit verification inputs
The Verifier SHALL receive a Graph-built verified-only payload rather than inferring business inputs from conversation history, ThreadLocal state, raw Executor text, or complete tool history.

#### Scenario: explicit input blocks available to Verifier
- **WHEN** the Verifier Graph Node starts
- **THEN** the payload SHALL provide `diagnosis_context`, `verified_executor_output`, `verified_evidence`, `gatekeeper_audit`, and `verdict_ceiling`
- **AND** permitted structured `retry_context` SHALL be provided only after evidence retry preparation

#### Scenario: Verifier remains isolated from intermediate and raw material
- **WHEN** the Verifier input is serialized
- **THEN** it SHALL exclude Planner reasoning, Executor intermediate reasoning, raw Executor text, complete tool trace summary, Prompt text, and unrelated parent Graph State

#### Scenario: only passed bindings are available
- **WHEN** Gatekeeper returns mixed passed and failed checked bindings
- **THEN** `verified_executor_output` and `verified_evidence` SHALL contain only claims/material matching passed bindings
- **AND** the Verifier SHALL NOT receive failed or unreferenced tool material

#### Scenario: verified evidence preserves precise references
- **WHEN** the system prepares Verifier input
- **THEN** each verified evidence item SHALL preserve claim id, source invocation id, tool name, raw path, and matched text
- **AND** the item SHALL be traceable to current-run Gatekeeper validation

#### Scenario: gatekeeper audit and ceiling are available
- **WHEN** the system prepares Verifier input
- **THEN** the payload SHALL include raw Gatekeeper audit separately from normalized verdict ceiling
- **AND** a LOW_CONFID ceiling SHALL prevent effective PASS

#### Scenario: technical retry occurs
- **WHEN** the first Verifier attempt returns invalid output or a retryable invocation failure
- **THEN** the second attempt SHALL receive byte-identical serialized input
- **AND** Executor, Gatekeeper, and tools SHALL NOT rerun

### Requirement: Verifier facts SHALL be auditable
Verifier claims and facts SHALL be linkable to the verified binding projection used during verification.

#### Scenario: claim checks contain evidence refs
- **WHEN** the Verifier emits `claim_checks`
- **THEN** each check SHALL include an `evidence_refs` array
- **AND** any non-empty evidence ref SHALL correspond to existing verified evidence by claim id, source invocation id, tool name, or raw path
- **AND** it SHALL NOT reference a failed or unverified binding

#### Scenario: verifier evaluation persists traceability snapshot
- **WHEN** Graph result mapping persists verifier evaluation
- **THEN** it SHALL include `traceability_version`
- **AND** it SHALL include the bounded `verified_evidence` snapshot used by the Verifier
- **AND** it SHALL NOT persist a complete tool trace summary as Verifier input

### Requirement: Structured Executor output SHALL degrade safely
The StateGraph runtime SHALL tolerate malformed or absent structured Executor output without crashing the Chat flow or invoking Verifier with untrusted material.

#### Scenario: Malformed Executor JSON is classified
- **WHEN** Executor returns malformed JSON or text outside the expected contract
- **THEN** Executor Node SHALL set INVALID_OUTPUT
- **AND** the Graph SHALL route directly to deterministic pre-verification Fallback
- **AND** Gatekeeper, Verifier, and model Composer SHALL NOT execute

#### Scenario: Structured parse failure remains observable
- **WHEN** Executor output parsing fails
- **THEN** orchestration events and verifier evaluation status/failure fields SHALL make the parse failure visible
- **AND** the failure SHALL NOT be treated as a successful evidence-attribution contract or diagnostic verdict

### Requirement: Executor Gatekeeper SHALL validate deterministic structured-output failures
The system SHALL run deterministic Gatekeeper checks as an explicit Graph Node after legal Executor output parsing and before Verifier model execution.

#### Scenario: schema rule rejects removed fields
- **WHEN** Executor structured output contains `diagnosis_summary` or `user_facing_answer`
- **THEN** `gatekeeper_result.status` SHALL be `fail`
- **AND** `gatekeeper_result.failed_rules` SHALL contain `schema.executor_v2`

#### Scenario: schema rule rejects missing evidence bindings
- **WHEN** a confirmed claim has no `evidence_bindings`
- **THEN** `gatekeeper_result.status` SHALL be `fail`
- **AND** `gatekeeper_result.failed_rules` SHALL contain `schema.executor_v2`

#### Scenario: invocation rule rejects fabricated invocation ids
- **WHEN** a claim evidence binding references an invocation id absent from current-run `tool_invocation` rows
- **THEN** `gatekeeper_result.status` SHALL be `fail`
- **AND** `gatekeeper_result.failed_rules` SHALL contain `evidence.invocation_ref`

#### Scenario: invocation rule rejects tool name mismatch
- **WHEN** a claim evidence binding references an existing current-run invocation id
- **AND** binding `tool_name` does not match persisted invocation `tool_name`
- **THEN** `gatekeeper_result.status` SHALL be `fail`
- **AND** `gatekeeper_result.failed_rules` SHALL contain `evidence.invocation_ref`

#### Scenario: valid structured output passes initial gatekeeper rules
- **WHEN** Executor emits legal `executor_evidence_v2`
- **AND** each claim has evidence bindings pointing to current-run invocations with matching tool names and paths
- **THEN** `gatekeeper_result.status` SHALL be `pass`
- **AND** `gatekeeper_result.failed_rules` SHALL be empty

#### Scenario: gatekeeper reject bypasses Verifier
- **WHEN** normalized Gatekeeper status is REJECT
- **THEN** the Graph SHALL route directly to pre-verification Fallback
- **AND** Verifier SHALL NOT execute

#### Scenario: gatekeeper low confidence is bounded
- **WHEN** normalized Gatekeeper status is LOW_CONFID with at least one passed binding
- **THEN** verified input SHALL contain only passed bindings
- **AND** effective verdict SHALL NOT exceed LOW_CONFID

### Requirement: Verifier SHALL use verified claim-local evidence for derivability
Verifier SHALL judge structured claims only against Gatekeeper-verified claim-local evidence excerpts and their precise current-run references.

#### Scenario: Verified excerpt supports direct observation
- **WHEN** verdict ceiling is PASS
- **AND** a claim's verified evidence matched text directly contains the claim's concrete facts
- **THEN** Verifier MAY classify that claim as `direct_observation`

#### Scenario: Verified evidence is complete Verifier context
- **WHEN** verified claims and evidence are available
- **THEN** Verifier SHALL use them as its evidence context
- **AND** it SHALL NOT require or request a complete tool trace summary
- **AND** it SHALL NOT read raw Executor or unreferenced tool material

### Requirement: Gatekeeper severity SHALL constrain effective verdict
Runtime effective verdict calculation SHALL treat normalized Gatekeeper ceiling as a hard upper bound independent from Verifier model output.

#### Scenario: Reject severity bypasses Verifier
- **WHEN** `gatekeeper_result.severity=reject`
- **THEN** the Graph SHALL route to pre-verification Fallback without invoking Verifier
- **AND** it SHALL NOT fabricate an effective diagnostic verdict

#### Scenario: Low confidence severity prevents PASS
- **WHEN** `gatekeeper_result.severity=low_confid`
- **AND** the Verifier model returns `verdict=PASS`
- **THEN** deterministic effective-verdict calculation SHALL downgrade the result
- **AND** effective verdict SHALL be `LOW_CONFID`

#### Scenario: Gatekeeper audit includes severity
- **WHEN** Graph verifier evaluation is persisted
- **THEN** `diagnosis_run.self_evaluation.verifier_evaluation.gatekeeper_result` SHALL include available `status`, `severity`, `checked_bindings`, `failed_rules`, `warnings`, and `errors`