openspec-apply-change

name: openspec-apply-change description: Implement tasks from an OpenSpec change. Use when the user wants to start implementing, continue implementation, or work through tasks. license: MIT compatibility: Requires openspec CLI. metadata: author: openspec version: "1.0" generatedBy: "1.1.1"

Implement tasks from an OpenSpec change.

Input: Optionally specify a change name. If omitted, check if it can be inferred from conversation context. If vague or ambiguous you MUST prompt for available changes.

Steps

1. Select the change

   If a name is provided, use it. Otherwise:

   • Infer from conversation context if the user mentioned a change
   • Auto-select if only one active change exists
   • If ambiguous, run openspec list --json to get available changes and use the AskUserQuestion tool to let the user select

   Always announce: "Using change: " and how to override (e.g., /opsx:apply <other>).

2. Check status to understand the schema

   openspec status --change "<name>" --json
   

   Parse the JSON to understand:

   • schemaName: The workflow being used (e.g., "spec-driven")
   • Which artifact contains the tasks (typically "tasks" for spec-driven, check status for others)

3. Get apply instructions

   openspec instructions apply --change "<name>" --json
   

   This returns:

   • Context file paths (varies by schema - could be proposal/specs/design/tasks or spec/tests/implementation/docs)
   • Progress (total, complete, remaining)
   • Task list with status
   • Dynamic instruction based on current state

   Handle states:

   • If state: "blocked" (missing artifacts): show message, suggest using openspec-continue-change
   • If state: "all_done": congratulate, suggest archive
   • Otherwise: proceed to implementation

4. Read context files

   Read the files listed in contextFiles from the apply instructions output. The files depend on the schema being used:

   • spec-driven: proposal, specs, design, tasks
   • Other schemes: follow the contextFiles from CLI output

5. Show current progress

   Display:

   • Schema being used
   • Progress: "N/M tasks complete"
   • Remaining tasks overview
   • Dynamic instruction from CLI

6. CRITICAL: Trust the Documentation - DO NOT INVENT

   ⚠️ Implementation Rule #1: Follow artifacts EXACTLY - do not improvise or "improve" ⚠️

   The artifacts (proposal.md, design.md, specs/*.md, tasks.md) contain EXTREMELY DETAILED instructions. They specify:

   • Exact UI element locations (which page, where on page)
   • Exact component reuse decisions (reuse X, modify Y, create new Z)
   • Exact navigation flows (PageA → PageB with parameters)
   • Exact XAML patterns (with property bindings)
   • Exact method signatures
   • Exact UX behaviors (inference logic, visual indicators, ordering)

   When implementing, you MUST:

   • ✅ Read ALL context files thoroughly before starting ANY task
   • ✅ Follow EXACTLY what the artifacts specify (locations, names, patterns)
   • ✅ Use the EXACT components/pages mentioned (do NOT substitute)
   • ✅ Copy XAML/code patterns from design.md examples when provided
   • ✅ Respect "FORBIDDEN" constraints from proposal.md/design.md
   • ✅ Follow component reuse matrix (reuse vs modify vs new)
   • ✅ Implement UI flows as documented (all navigation steps with parameters)
   • ✅ Use exact configuration values from tasks.md (e.g., ItemsSource lists)

   You MUST NEVER:

   • ❌ "Improve" or "optimize" the design (implement what's specified, suggest improvements separately)
   • ❌ Put UI elements in different locations than specified
   • ❌ Create new components when artifacts say to reuse existing ones
   • ❌ Substitute one page for another because "it seems similar"
   • ❌ Add features not in the artifacts (scope creep)
   • ❌ Skip steps in documented UI flows
   • ❌ Assume UX patterns without checking documentation
   • ❌ Make up method signatures when specs provide exact signatures

   Example violations to AVOID:

   • Artifact says "Add button in SettingsPage below Clear Target" → ❌ You put it in a submenu
   • Artifact says "Reuse SearchPage in ingredient-selection mode" → ❌ You create new IngredientSearchPage
   • Artifact says "Show [R] badge for recipes" → ❌ You use a different visual indicator
   • Artifact specifies exact method signature → ❌ You add extra parameters "for flexibility"

   If you find issues with the documentation:

   • PAUSE implementation
   • Report the specific issue or ambiguity
   • Suggest updating the artifact (use openspec-continue-change to fix it)
   • DO NOT "fix it yourself" by inventing - get clarification first

   Trust the artifacts - they were created with extreme care and detail. Your job is faithful implementation, not creative interpretation.

7. Implement tasks (loop until done or blocked)

   For each pending task:

   • Show which task is being worked on
   • Make the code changes required
   • Keep changes minimal and focused
   • Mark task complete in the tasks file: - [ ] → - [x]
   • Continue to next task

   Pause if:

   • Task is unclear → ask for clarification
   • Implementation reveals a design issue → suggest updating artifacts
   • Error or blocker encountered → report and wait for guidance
   • User interrupts

8. On completion or pause, show status

   Display:

   • Tasks completed this session
   • Overall progress: "N/M tasks complete"
   • If all done: suggest archive
   • If paused: explain why and wait for guidance

Output During Implementation

## Implementing: <change-name> (schema: <schema-name>)

Working on task 3/7: <task description>
[...implementation happening...]
✓ Task complete

Working on task 4/7: <task description>
[...implementation happening...]
✓ Task complete

Output On Completion

## Implementation Complete

**Change:** <change-name>
**Schema:** <schema-name>
**Progress:** 7/7 tasks complete ✓

### Completed This Session
- [x] Task 1
- [x] Task 2
...

All tasks complete! Ready to archive this change.

Output On Pause (Issue Encountered)

## Implementation Paused

**Change:** <change-name>
**Schema:** <schema-name>
**Progress:** 4/7 tasks complete

### Issue Encountered
<description of the issue>

**Options:**
1. <option 1>
2. <option 2>
3. Other approach

What would you like to do?

Guardrails

• Keep going through tasks until done or blocked
• Always read context files before starting (from the apply instructions output)
• If task is ambiguous, pause and ask before implementing
• If implementation reveals issues, pause and suggest artifact updates
• Keep code changes minimal and scoped to each task
• Update task checkbox immediately after completing each task
• Pause on errors, blockers, or unclear requirements - don't guess
• Use contextFiles from CLI output, don't assume specific file names

Fluid Workflow Integration

This skill supports the "actions on a change" model:

• Can be invoked anytime: Before all artifacts are done (if tasks exist), after partial implementation, interleaved with other actions
• Allows artifact updates: If implementation reveals design issues, suggest updating artifacts - not phase-locked, work fluidly