OpenSpec Implement Skill

When to Invoke

Automatically activate when user:

• Says “Implement this change”, “Apply the fix”, “Execute proposal”
• Asks “Apply this bug fix”, “Implement the proposal”, “Execute the change”
• Has an approved OpenSpec proposal ready to implement
• Mentions “implement”, “apply”, “execute” with Level 0-1 context
• Uses words like: apply, execute, implement, change, fix, proposal

Specific trigger phrases:

• “Implement this change”
• “Apply the bug fix”
• “Execute the proposal”
• “Apply this change: [proposal-id]”
• “Implement proposal [X]”
• “Execute the fix”

Prerequisites:

• OpenSpec proposal exists and is approved
• Change is still Level 0-1 (hasn’t grown in scope)
• Environment and dependencies are clear

Do NOT invoke when:

• No proposal exists (use openspec-change-proposal first)
• Scope has grown beyond Level 1 (escalate to BMAD)
• Implementing a BMAD story (use bmad-development-execution instead)

Auto-escalate to BMAD when:

• Implementation reveals hidden complexity
• Scope expands beyond original proposal
• Tests fail repeatedly indicating design issues

Mission

Apply small code or configuration changes approved via OpenSpec proposals, ensuring each task is executed transparently with testing evidence.

Inputs Required

• proposal: latest proposal.md with decision history
• tasks: tasks.md with sequenced work items and owners
• environment: information about repositories, branches, and tooling needed for execution

Outputs

• Code or configuration changes committed according to tasks
• Test results demonstrating acceptance criteria were met
• Updated proposal/tasks capturing status and follow-ups
• execution-log.md documenting commands and evidence (template: assets/execution-log-template.md.template)

scripts/update_execution_log.py appends timestamped entries to the execution log inside openspec/changes/<change-id>/.

Process

1. Confirm scope and prerequisites via CHECKLIST.md.
2. Plan work referencing affected files and dependencies.
3. Implement tasks iteratively, documenting commands and results in execution-log.md via the script or manual edits.
4. Run relevant tests or validation steps after each change and capture evidence in the log.
5. Update artifacts and communicate completion or blockers.

Quality Gates

All checklist items must pass. If complexity grows beyond Level 1, escalate back to BMAD pathways.

Error Handling

• When prerequisites or environment setup are missing, stop and request clarity.
• If tests fail or scope expands, log findings and recommend next actions, including potential migration to BMAD development-execution.