PRD Verifier Skill

PRD Verifier Skill

Status: Stub (contract defined, implementation pending)

Purpose

Verifies implementation completeness and quality against PRD requirements, specifications, and quality standards. This skill is invoked by the loop-core platform before loop exit when require_verification_pass is enabled.

Input/Output Contract

Inputs

The verification skill receives the following context from loop-core:

1. PRD/Spec Path (required)

   • Source: Config or plan metadata
   • Format: File path (relative to project root)
   • Example: docs/PRD.md or spec/requirements.md
   • Purpose: Defines requirements to verify against

2. Plan Path (required)

   • Source: Loop state (from loop_state.json)
   • Format: File path (relative to project root)
   • Example: .claude/loop/plan-{terminal_id}.md
   • Purpose: Defines planned implementation to verify

3. Codebase Directory (required)

   • Source: Current working directory
   • Format: Directory path
   • Example: /path/to/project
   • Purpose: Source code to verify

4. Verification Fields (optional, defaults from config)

   • Source: config.yaml verification.fields
   • Format: List of field names
   • Default: ["prd_coverage", "spec_compliance", "implementation_quality"]
   • Purpose: Define which verification aspects to include

Outputs

The verification skill produces the following artifacts:

1. Verification Report (required)

   • Path: From config.yaml verification.write_report
   • Default: .claude/loop/verification-report.md
   • Format: Markdown
   • Required sections:

     # Verification Report
     
     ## Summary
     [PASS/FAIL] - Brief overall status
     
     ## PRD Coverage
     - Requirements addressed: X/Y
     - Missing requirements: [list]
     - Coverage percentage: Z%
     
     ## Spec Compliance
     - Spec requirements met: X/Y
     - Deviations: [list]
     - Compliance percentage: Z%
     
     ## Implementation Quality
     - Code quality score: X/Y
     - Critical issues: [list]
     - Recommendations: [list]
     
     ## Detailed Findings
     [Per-field detailed analysis]
     

2. Verification Passed Flag (required)

   • Location: loop_state.json
   • Key: verification_passed
   • Type: Boolean
   • Purpose: Signals to loop-core whether verification passed
   • Format:

     {
       "verification_passed": true|false,
       "verification_report": ".claude/loop/verification-report.md",
       "verification_timestamp": "2026-03-15T12:34:56Z"
     }
     

Verification Fields

prd_coverage

Verifies that all PRD requirements are addressed:

• Functional requirements implementation
• Non-functional requirements (performance, security, etc.)
• User stories and use cases
• Acceptance criteria

spec_compliance

Verifies compliance with technical specifications:

• API contract adherence
• Data structure compliance
• Architecture pattern compliance
• Integration point correctness

implementation_quality

Verifies code quality and best practices:

• Code organization and structure
• Error handling completeness
• Testing coverage
• Documentation quality
• Performance characteristics

Invocation Context

This skill is automatically invoked by loop-core when:

1. Loop exit policy conditions are met
2. require_verification_pass is enabled in config
3. All other exit criteria are satisfied

Error Handling

If verification fails:

• Set verification_passed: false in loop_state
• Write detailed findings to verification report
• Loop-core will NOT exit, allowing iteration to continue

If verification encounters an error:

• Report error to verification report
• Set verification_passed: false
• Log error to verifier.log

Implementation

STATUS: Implemented (TASK-015 Complete)

The verification logic is implemented in skills/prd_verifier/verifier.py with:

1. PRDVerifier class: Main verification orchestrator

   • Accepts PRD path, plan path, codebase directory, and config
   • Runs verification for specified fields
   • Generates structured markdown reports
   • Returns VerificationResult with pass/fail status

2. Verification dimensions:

   • prd_coverage: Extracts requirements from plan, matches against completed tasks
   • spec_compliance: Validates against PRD technical specifications
   • implementation_quality: Scores completion rate and checks for user concerns

3. Convenience function: run_verification() for quick invocation

4. Integration: Works with loop_policy.py for practical verification

Configuration Integration

This skill integrates with .claude/loop/config.yaml:

verification:
  enabled: true
  skill: prd-verifier  # This skill
  write_report: .claude/loop/verification-report.md
  fields:
    - prd_coverage
    - spec_compliance
    - implementation_quality

Testing

Test cases should verify:

• PASS scenario: All requirements met
• FAIL scenario: Missing requirements
• FAIL scenario: Quality issues below threshold
• ERROR scenario: Missing PRD file
• ERROR scenario: Invalid codebase path
• PARTIAL scenario: Some requirements met

Related Files

• Config schema: scripts/config_schema.py (VerificationConfig)
• Loop state: scripts/state_manager.py
• Exit policy: scripts/loop_policy.py
• Integration test: tests/test_integration.py