Diff Spec Changes

Preview the impact of spec.md changes on downstream artifacts before propagating. Use this to understand the blast radius of a refinement.

User Input

$ARGUMENTS

You MUST consider the user input before proceeding (if not empty).

Prerequisites

1. Verify a spec-kit project exists by checking for .specify/ directory
2. Locate the current feature's spec directory
3. Verify spec.md exists

Outline

1. Load all artifacts: Read from the current feature directory:

   • spec.md (check for **Refined**: entries)
   • plan.md (if exists)
   • tasks.md (if exists)

2. Extract refinement history: Parse all **Refined**: entries in spec.md to build a change log:

   ## Refinement History
   - [DATE]: [Description of change]
   - [DATE]: [Description of change]
   

3. Analyze spec changes: For each refinement, classify the impact:

   Change Type	Spec Impact	Plan Impact	Tasks Impact
   New user story	New section added	New structure/complexity entry	New phase with tasks
   Modified requirement	Updated requirement text	May affect technical context	May affect task descriptions
   Removed requirement	Strikethrough marking	Sections to mark removed	Tasks to mark removed
   Changed priority	Reordered user story	May affect implementation order	May reorder phases
   New success criterion	Added to criteria list	Minimal	May need verification task

4. Generate impact report: Output a structured diff report:

   # Spec Refinement Impact Report
   
   ## Changes Detected
   - [List each change from refinement notes]
   
   ## Downstream Impact
   
   ### plan.md
   - **Status**: [Up to date | Stale | Does not exist]
   - **Sections affected**: [List of plan sections that need updates]
   - **Estimated changes**: [Number of sections to add/modify/remove]
   
   ### tasks.md
   - **Status**: [Up to date | Stale | Does not exist]
   - **Tasks affected**: [List of task IDs that need updates]
   - **New tasks needed**: [Count]
   - **Tasks to mark removed**: [Count]
   - **Dependency changes**: [Yes/No — describe if yes]
   
   ## Consistency Check
   - [ ] All spec user stories have plan sections: [Pass/Fail]
   - [ ] All spec requirements have task coverage: [Pass/Fail]
   - [ ] No orphaned tasks from removed requirements: [Pass/Fail]
   
   ## Recommended Action
   - Run `/speckit.refine.propagate` to apply these changes
   - Or run `/speckit.refine.propagate only plan` to update plan.md first
   

5. Report: Output the impact report. Do not modify any files — this command is read-only.

Rules

• Read-only — this command never modifies any files
• Always show impact — even if no downstream artifacts exist, report what would be needed
• Be specific — list exact section names and task IDs affected, not vague summaries