OpenSpec Apply Skill

Use /opsx:apply to implement tasks from a change. The agent reads tasks.md, works through tasks one by one, writes code, creates files, runs tests as needed, and checks off completed items with [x].

When to Use

• All planning artifacts are complete and the user wants to implement.
• The user says "implement", "apply", "start coding", "execute tasks".
• Resuming implementation after an interruption.

Prerequisites

• Planning artifacts complete — at minimum tasks.md exists (created via openspec-ff or openspec-continue).

Workflow

1. Start implementation

   • /opsx:apply — apply the current/inferred change.
   • /opsx:apply <change-name> — apply a specific change.

2. Read tasks

   • The agent reads tasks.md and identifies incomplete tasks (unchecked [ ] items).

3. Work through tasks

   • For each task: read relevant specs, design, and existing code; write code; create/modify files; run tests.
   • Mark each task complete with [x] in tasks.md.

4. Handle issues

   • If a task reveals that the design was wrong, edit the artifact (e.g. design.md) and continue.
   • OpenSpec is fluid — updating artifacts during implementation is expected and encouraged.

5. Resume if interrupted

   • Run /opsx:apply again; it picks up where it left off based on checkbox state.

Outputs

• Code changes (new files, modified files) implementing the tasks.
• tasks.md updated with [x] for completed tasks.

Next Steps

• Use openspec-verify to validate implementation matches artifacts.
• Use openspec-archive to archive the completed change.

Troubleshooting

• "Change not found": Specify the change name: /opsx:apply add-dark-mode.
• Tasks seem wrong: Edit tasks.md (or use /opsx:continue to regenerate) before applying.
• Implementation diverges from design: Edit design.md or specs/ as needed; OpenSpec is iterative.

References

• OpenSpec Commands: /opsx:apply
• OpenSpec Concepts: Artifacts