skill CX Codex

openspec-implementation — Claude Code skill: setup and overview

Q: How to install openspec-implementation in Claude Code?

Run `npx skills add forztf/open-skilled-sdd --skill openspec-implementation -a claude-code`.

Executes approved OpenSpec proposals sequentially, testing each task before marking it done and tracking everything in TodoWrite.

Install into Claude Code · Skills CLI (Vercel) All methods and platforms ↓

npx skills add forztf/open-skilled-sdd --skill openspec-implementation -a claude-code

Open on GitHub

What openspec-implementation does

This skill guides the agent through implementing approved OpenSpec proposals. It starts by loading context from proposal.md, task lists in tasks.md, and requirement changes inside the specs folder.

Execution relies on a strict loop: read, implement, run tests, and confirm acceptance criteria. The agent loads items into TodoWrite beforehand. Tasks are tackled one by one in exact order. Batching edits or skipping verification is not permitted. When a blocker occurs, the agent keeps the task marked as in-progress and creates a distinct task to address the obstacle.

Spec deltas remain frozen during development. Any necessary adjustments wait until the archive stage. Once all tasks pass testing, the agent creates spec/changes/{change-id}/IMPLEMENTED with a timestamp marker.

What it helps with

execute specification tasks sequentially without missing steps
validate code with tests and linters after every single change
keep visible task progress up to date using TodoWrite
record verified completion in the IMPLEMENTED marker file

Example prompts for the agent

Implement approved proposal spec/changes/auth-v2 step by step
Work through tasks for billing-setup with TodoWrite tracking
Apply changes from user-profile spec and verify each completed task

How to install openspec-implementation

1Skills CLI (Vercel)

npx skills add forztf/open-skilled-sdd --skill openspec-implementation -a claude-code

2Manually: put the files in place

~/.claude/skills/openspec-implementation/SKILL.md

Copy the whole skill folder; for one project use .claude/skills/openspec-implementation/

1Skills CLI (Vercel)

npx skills add forztf/open-skilled-sdd --skill openspec-implementation -a codex

2Manually: put the files in place

.agents/skills/openspec-implementation/SKILL.md

For all projects use ~/.agents/skills/

1Skills CLI (Vercel)

npx skills add forztf/open-skilled-sdd --skill openspec-implementation -a cursor

2Manually: put the files in place

.cursor/skills/openspec-implementation/SKILL.md

Cursor also reads .agents/skills/ and .claude/skills/

1GitHub CLI

gh skill install forztf/open-skilled-sdd openspec-implementation

2Manually: put the files in place

.github/skills/openspec-implementation/SKILL.md

1Skills CLI (Vercel)

npx skills add forztf/open-skilled-sdd --skill openspec-implementation -a gemini-cli

2Platform CLI

gemini skills install https://github.com/forztf/open-skilled-sdd --path skills/openspec-implementation

Manually: put the files in place

.devin/skills/openspec-implementation/SKILL.md

The legacy .windsurf/skills/ path still works

Skills CLI (Vercel)

npx skills add forztf/open-skilled-sdd --skill openspec-implementation -a opencode

Step by step, with commands for each platform: How to install skills in Claude Code: five ways

Questions about openspec-implementation

How to install openspec-implementation in Claude Code?

Run npx skills add forztf/open-skilled-sdd --skill openspec-implementation -a claude-code.

What does openspec-implementation do?

It systematically processes tasks from an approved OpenSpec change, running tests at each checkpoint and updating status in TodoWrite.

Can the agent update spec deltas while writing code?

No, spec deltas cannot be edited during implementation. Any discrepancies must be noted for later merging during the archive phase.

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