Spec Kit is an open source toolkit that gives AI coding agents structured
processes, reusable templates, and documented outcomes. Start with a ready-made
process, customize it, or bring your own.
## Choose your process
| What you need | Process | Outcome |
| --- | --- | --- |
| Build a feature or application | [Spec-Driven Development](#spec-driven-development) | A specification carried through planning, implementation, and convergence |
| Diagnose and repair broken behavior | [Bug fixing](#bug-fixing) | An assessed cause, scoped fix, and recorded verification |
| Decide whether an idea deserves investment | [Idea assessment](#idea-assessment) | An evidence-backed go, clarify, or stop decision |
| Adopt or create a different process | [Your own process](#capabilities) | A process adapted or assembled from reusable primitives |
These are **independent entry points**, not mandatory phases. SDD ships in core;
bug fixing and assessment are bundled extensions you install when needed, and
the primitives below let you adopt or create other processes.
## Capabilities
Spec Kit combines ready-to-use processes with composable mechanisms:
| Capability | Spec Kit mechanism |
| --- | --- |
| Connect to or switch between coding agents | [Integration](https://github.github.io/spec-kit/reference/integrations.html) |
| Add a command, quality gate, or complete process | [Extension](https://github.github.io/spec-kit/reference/extensions.html) |
| Connect a process to an external tool or service | [Extension](https://github.github.io/spec-kit/reference/extensions.html) |
| React to coding-agent lifecycle events | [Extension event hook](https://github.github.io/spec-kit/reference/extensions.html#project-extension-and-hook-configuration) |
| Adapt templates, commands, terminology, or methodology | [Preset](https://github.github.io/spec-kit/reference/presets.html) |
| Enforce organizational or regulatory standards | [Preset](https://github.github.io/spec-kit/reference/presets.html) |
| Override a template for one project | [Project-local override](https://github.github.io/spec-kit/guides/customization.html#project-local-overrides-and-resolution) |
| Automate prompts, commands, gates, and shell tasks | [Workflow](https://github.github.io/spec-kit/reference/workflows.html) |
| Modify an installed workflow without forking it | [Workflow overlay](https://github.github.io/spec-kit/reference/workflows.html#workflow-overlays) |
| Add reusable executable behavior to workflows | [Workflow step](https://github.github.io/spec-kit/reference/workflows.html#custom-step-packages) |
| Install a curated setup for a role or team | [Bundle](https://github.github.io/spec-kit/reference/bundles.html) |
| Discover community components | Catalog |
| Host a private catalog of approved components | Catalog |
| Access private catalogs and component downloads | [Authentication](https://github.github.io/spec-kit/reference/authentication.html) |
| Work offline or behind a firewall | [Local sources and self-hosted catalogs](https://github.github.io/spec-kit/install/air-gapped.html) |
| Inspect which layer supplies a command, template, or script | [Artifact inventory](https://github.github.io/spec-kit/reference/artifacts.html) |
Search the active catalogs with commands such as `specify extension search`,
`specify preset search`, `specify workflow search`, and `specify bundle search`.
Spec Kit includes community catalogs, and organizations can add their own
curated sources. Catalog listings are not audits or endorsements, so review
community source code before installing or running it.
## Get started
You need **Python 3.11+**, **[uv](https://github.github.io/spec-kit/install/uv.html)**,
and a supported AI coding agent on Linux, macOS, or Windows.
For **CLI setup only**, run this in your terminal to install Spec Kit and create a project:
```bash
uv tool install specify-cli
specify init my-project --integration copilot
cd my-project
```
The examples use **GitHub Copilot's default skills mode**. Replace `copilot` with
your [integration key](https://github.github.io/spec-kit/reference/integrations.html)
to use another supported agent.
Already have code? Follow the
[existing-project guide](https://github.github.io/spec-kit/guides/existing-projects.html).
For pinned releases, other installers, CI, or troubleshooting, see
[Installation](https://github.github.io/spec-kit/installation.html).
To update an existing installation, see [Upgrade](https://github.github.io/spec-kit/upgrade.html).
Now **launch your coding agent in the project directory** and choose a process
below. Invoke each `/speckit-*` **skill in your agent's chat**, one at a time,
and review the result before continuing. These are agent skills, not terminal
commands. Other agents and modes may use
[different invocation syntax](https://github.github.io/spec-kit/reference/integrations.html#command-invocation).
## Spec-Driven Development
Define **what and why** before deciding **how** to build it. SDD turns your
requirements into a specification, a technical plan, and actionable tasks,
then guides implementation against those artifacts.
**Constitution once per project; specify → plan → tasks → implement → converge per feature.**
Invoke these skills in your agent's chat:
```text
/speckit-constitution Create principles focused on code quality, testing, and maintainability.
/speckit-specify Build a photo organizer with albums grouped by date and a tile preview of each album.
/speckit-plan Use Vite with vanilla JavaScript. Keep images local and store metadata in SQLite.
/speckit-tasks
/speckit-implement
/speckit-converge
```
Repeat **implement → converge** until convergence reports **Converged**.
Add clarification, checklists, and consistency analysis when you need extra
quality gates.
[SDD walkthrough](https://github.github.io/spec-kit/quickstart.html) ·
[Command reference](https://github.github.io/spec-kit/reference/agentic-sdd.html)
## Bug fixing
Keep diagnosis, repair, and verification separate so the agent fixes the assessed
cause and checks the original symptom. No SDD feature workflow is required first.
**CLI setup (terminal):** install the opt-in extension from the project directory:
```bash
specify extension add bug
```
Then invoke the **assess → fix → test** skills in your agent's chat:
```text
/speckit-bug-assess "Submitting an empty password crashes the login form." slug=login-crash
/speckit-bug-fix slug=login-crash
/speckit-bug-test slug=login-crash
```
The reports live in `.specify/bugs/login-crash/`. Review the final verdict:
`verified`, `partial`, or `failed`. Missing verification is not a successful fix.
[Bug-fixing walkthrough](https://github.github.io/spec-kit/guides/bugfix.html) ·
[Command reference](https://github.github.io/spec-kit/reference/agentic-bugfix.html)
## Idea assessment
Gather evidence before committing to an idea, whether or not it becomes software.
This standalone process works even in a project with no source code.
**CLI setup (terminal):** install the opt-in extension from the project directory:
```bash
specify extension add assess
```
Then invoke the **intake → research → define → shape → decide** skills in your agent's chat:
```text
/speckit-assess-intake "Let users work offline and sync when they reconnect." slug=offline-mode
/speckit-assess-research slug=offline-mode
/speckit-assess-define slug=offline-mode
/speckit-assess-shape slug=offline-mode
/speckit-assess-decide slug=offline-mode
```
The artifacts live in `.specify/assessments/offline-mode/`, ending in a
**go / needs-clarification / kill** decision. Resolve unknowns by refining the
existing Markdown artifacts directly or with the agent, rather than regenerating
whole stages. A `go` decision can be handed to `/speckit-specify` if you choose
to build it; stopping with a documented reason is also a useful result.
[Assessment walkthrough](https://github.github.io/spec-kit/guides/assessment.html) ·
[Command reference](https://github.github.io/spec-kit/reference/agentic-assessment.html)
## Customize or bring your own process
**Extensions** add capabilities, **presets** adapt existing behavior,
**workflows** automate steps, and **bundles** package a role-based setup.
Use project-local overrides for one-off template changes.
[Customization guide](https://github.github.io/spec-kit/guides/customization.html) ·
[Community extensions, presets, bundles, and walkthroughs](https://github.github.io/spec-kit/community/overview.html)
## Documentation
- [CLI reference](https://github.github.io/spec-kit/reference/overview.html) and [process commands](https://github.github.io/spec-kit/reference/agentic-sdd.html#command-overview)
- [SDD philosophy](https://github.github.io/spec-kit/concepts/sdd.html), [full methodology](https://github.com/github/spec-kit/blob/HEAD/spec-driven.md), and [evolving existing specs](https://github.github.io/spec-kit/guides/evolving-specs.html)
- [Video overview](https://github.github.io/spec-kit/quickstart.html#video-overview) and [project history](https://github.github.io/spec-kit/history.html)
- [How Spec Kit uses Spec Kit](https://github.com/github/spec-kit/blob/HEAD/CONTRIBUTING.md#does-spec-kit-use-spec-kit)
## Star history
Thanks to everyone who helps Spec Kit shine.
## Support and contributing
[Report a bug or request a feature](https://github.com/github/spec-kit/issues/new) ·
[Contributing guide](https://github.com/github/spec-kit/blob/HEAD/CONTRIBUTING.md) · [Code of conduct](https://github.com/github/spec-kit/blob/HEAD/CODE_OF_CONDUCT.md)
Spec Kit is [MIT licensed](https://github.com/github/spec-kit/blob/HEAD/LICENSE).
