🌱 Spec Kit
Build with a spec, fix a bug, or assess an idea — with your coding agent.
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 | A specification carried through planning, implementation, and convergence |
| Diagnose and repair broken behavior | Bug fixing | An assessed cause, scoped fix, and recorded verification |
| Decide whether an idea deserves investment | Idea assessment | An evidence-backed go, clarify, or stop decision |
| Adopt or create a different process | Your own process | 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 |
| Add a command, quality gate, or complete process | Extension |
| Connect a process to an external tool or service | Extension |
| React to coding-agent lifecycle events | Extension event hook |
| Adapt templates, commands, terminology, or methodology | Preset |
| Enforce organizational or regulatory standards | Preset |
| Override a template for one project | Project-local override |
| Automate prompts, commands, gates, and shell tasks | Workflow |
| Modify an installed workflow without forking it | Workflow overlay |
| Add reusable executable behavior to workflows | Workflow step |
| Install a curated setup for a role or team | Bundle |
| Discover community components | Catalog |
| Host a private catalog of approved components | Catalog |
| Access private catalogs and component downloads | Authentication |
| Work offline or behind a firewall | Local sources and self-hosted catalogs |
| Inspect which layer supplies a command, template, or script | Artifact inventory |
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, 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:
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
to use another supported agent.
Already have code? Follow the existing-project guide. For pinned releases, other installers, CI, or troubleshooting, see Installation. To update an existing installation, see Upgrade.
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.
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:
/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 · Command reference
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:
specify extension add bug
Then invoke the assess → fix → test skills in your agent's chat:
/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 · Command reference
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:
specify extension add assess
Then invoke the intake → research → define → shape → decide skills in your agent's chat:
/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 · Command reference
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 · Community extensions, presets, bundles, and walkthroughs
Documentation
- CLI reference and process commands
- SDD philosophy, full methodology, and evolving existing specs
- Video overview and project history
- How Spec Kit uses Spec Kit
Star history
Thanks to everyone who helps Spec Kit shine.
Support and contributing
Report a bug or request a feature · Contributing guide · Code of conduct
Spec Kit is MIT licensed.
1 maintainer
Metadata
1 maintainer
Release files for specify-cli 1.2.1
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | |
|---|---|---|---|
| specify_cli-1.2.1.tar.gz | 5.0 MB | Details |
Built distribution (wheel)
| File | Interpreter | ABI | Platform | Reset |
|---|---|---|---|---|
| specify_cli-1.2.1-py3-none-any.whl | Python 3 | none | any | Details |
Total release size: 6.2 MB
Release files / specify_cli-1.2.1.tar.gz
| Download URL | specify_cli-1.2.1.tar.gz |
|---|---|
| Size | 5.0 MB |
| Tags | Source |
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Release files / specify_cli-1.2.1-py3-none-any.whl
| Download URL | specify_cli-1.2.1-py3-none-any.whl |
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| Tags | Python 3 |
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SHA-256 checksum How to use checksums |
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Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
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