openspec-apply-change

name	openspec-apply-change
description	Implement a change by working through its tasks. Use when the user wants to apply/implement a change that has completed artifacts (specs, design, tasks).
license	MIT
compatibility	Requires openspec CLI.
metadata	{"author":"openspec","version":"1.0","generatedBy":"1.1.1"}

Apply a change by implementing its tasks using the specs and design as guidance.

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. If no change name provided, prompt for selection

   Run openspec list --json to get available changes. Use the AskUserQuestion tool to let the user select which change to implement.

   Show only changes that have tasks ready (not already archived).

   IMPORTANT: Do NOT guess or auto-select a change. Always let the user choose.

2. Load change context

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

   Parse the JSON to get:

   • specs: Completed spec artifacts to reference during implementation
   • design: Technical design decisions to follow
   • tasks: Implementation checklist with task items

   Read all referenced artifact files for full context.

3. Work through tasks sequentially

   For each incomplete task (- [ ]) in the tasks file:

   a. Announce which task you are working on b. Read relevant specs and design sections for context c. Implement the change in the codebase d. Mark the task as complete (- [x]) in the tasks file e. Show brief progress: what was done and what files were changed

4. After completing all tasks, show final status

   openspec status --change "<name>"
   

Output

After completing implementation, summarize:

• Change name
• List of tasks completed
• Files modified/created
• Prompt: "All tasks complete! Run /opsx:verify to check implementation or /opsx:archive to finalize."

Guardrails

• Always read specs and design before implementing
• Implement ONE task at a time, marking it complete before moving to the next
• Follow the design decisions documented in the change artifacts
• If a task is unclear, ask the user before implementing
• Do not skip tasks or implement out of order
• Keep implementation aligned with the specs — if something conflicts, flag it
• IMPORTANT: context and rules from instructions are constraints for YOU, not content for files