| 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. |
| allowed-tools | Bash(openspec:*) |
| license | MIT |
| compatibility | Requires openspec CLI. |
| metadata | {"author":"openspec","version":"1.0","generatedBy":"1.6.0"} |
Implement tasks from an OpenSpec change.
Local Workflow Customizations
The steps labeled Local Customization are repository-specific additions layered on top of the upstream OpenSpec skill. Keep them grouped when merging future upstream updates so the local workflow policy stays easy to review and reapply.
Store selection: If the user names a store (a store is a standalone OpenSpec repo registered on this machine) or the work lives in one, run openspec store list --json to discover registered store ids, then pass --store <id> on the commands that read or write specs and changes (new change, status, instructions, list, show, validate, archive, doctor, context). Other commands do not take the flag. Hints printed by commands already carry the flag; keep it on follow-ups. Without a store, commands act on the nearest local openspec/ root.
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
-
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>).
-
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")
planningHome, changeRoot, and actionContext: planning scope and edit constraints
- Which artifact contains the tasks (typically "tasks" for spec-driven, check status for others)
-
Local Customization: commit planning artifacts before apply when needed
Inspect git status before implementation begins.
- If the selected change's planning artifacts are already committed, continue.
- If files under the selected change's planning artifacts are uncommitted, stage only the files relevant to that change and create a commit before proceeding into apply.
- If unrelated uncommitted work would be swept into that commit, pause and ask the user how to proceed rather than bundling unrelated changes.
- This is a phase-boundary checkpoint only; do not create an additional "end-of-apply" commit in this skill.
-
Get apply instructions
openspec instructions apply --change "<name>" --json
This returns:
contextFiles: artifact ID -> array of concrete 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
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)
- Commit the selected change's planning artifacts before entering apply when that phase boundary has uncommitted work
- Do not create a post-implementation commit in apply; archive handles the next commit checkpoint when needed
- Do not treat commit/sync/archive workflow actions as implementation tasks
- 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