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

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")

• Which artifact contains the tasks (typically "tasks" for spec-driven, check status for others)

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

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 schemas: follow the contextFiles from CLI output

Show current progress

Display:

• Schema being used

• Progress: "N/M tasks complete"

• Remaining tasks overview

• Dynamic instruction from CLI

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

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

• Task 1
• 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