Specfly

Push a change proposal, get a reviewable pull request with its implementation.

Specfly is a Spec-Driven Development tooling. It builds on awesome OpenSpec to make coding with LLMs efficient and secure.

Why Specfly

• 🔑 You own it. Your key, your runner, your repo — you control the cost, the data, and the flow.
• 🛡️ Safe unattended runs. The agent runs in an ephemeral, isolated GitHub Actions environment.
• 🧩 Free and open. Supports any popular tech stack and drops into bigger workflows cleanly.
• 🥇 Best practices. Stay efficient in the long run with spec-driven advantage.

How it works

1. Create a new change proposal with /opsx:propose Claude Code command.
2. Review the change proposal files locally - it should accurately describe what you want to achieve with your change; prompt any changes that you think are needed.
3. Trigger the change implementation with /sfx:apply <change-name>.
4. Review & test the implementation PR; prompt any changes that you think are needed, and you can apply them again.
5. Archive the change with /opsx:archive, commit & push, approve and merge the PR.
6. Repeat.

Get started

From inside a clone of your GitHub repo (with an authenticated gh and git):

curl -fsSL https://specfly.dev/install.sh | bash

The installer does the mechanical setup (caller workflow, /sfx:apply command file, ANTHROPIC_API_KEY secret, optional main ruleset) and walks you through the browser-only steps (OpenSpec init, GitHub App install, API-key creation). It is safe to re-run.

Prefer to do it by hand? The manual steps

1. Install OpenSpec - the spec-driven development framework.
2. Install the Specfly App at github.com/apps/specfly - pick your repos.
3. Add one secret — ANTHROPIC_API_KEY - your own key.
4. Add one caller workflow — see examples/adopter-workflow.yml.
5. Copy one command file — .claude/commands/sfx/apply.md; then /sfx:apply <change-name> triggers an apply.
6. (Recommended) Protect main — require a PR + 1 approval, block direct pushes: Protecting main.

Full walkthrough, the per-change usage flow, and how to fine-tune for your stack are in Getting started.

Documentation

• Design overview — how Specfly is built and why.
• Getting started — full adopter setup and usage flow.
• Fine-tuning for your stack — environment provisioning on any toolchain.
• Protecting main — the branch ruleset that keeps unreviewed code off main.
• Backend reference — control-plane engineering reference.

See the documentation index for the full map.

License

MIT © Foster Systems