Extensions Overview

Guide for using Spec Kit extensions to add commands, external tool integrations, quality gates, and other capabilities beyond the built-in Spec-Driven Development process.

Table of Contents

  1. Introduction
  2. Getting Started
  3. Finding Extensions
  4. Installing Extensions
  5. Using Extensions
  6. Managing Extensions
  7. Configuration
  8. Troubleshooting
  9. Best Practices

Introduction

What are Extensions?

Extensions are modular packages that add new commands and functionality to Spec Kit without bloating the core framework. They allow you to:

  • Integrate with external tools (Jira, Linear, GitHub, etc.)
  • Automate repetitive tasks with hooks
  • Customize workflows for your team
  • Share solutions across projects

Why Use Extensions?

  • Clean Core: Keeps spec-kit lightweight and focused
  • Optional Features: Only install what you need
  • Community Driven: Anyone can create and share extensions
  • Version Controlled: Extensions are versioned independently

Specification artifact maintenance

An extension can define commands or hooks that reconcile spec.md, plan.md, and tasks.md during or after feature delivery. Any such edits follow the extension's documented behavior and the project's governance; they are not performed by, or added to the responsibilities of, the core Spec Kit commands. The team's persistence model separately determines how artifacts are maintained after delivery.

Getting Started

Prerequisites

  • A current Spec Kit release compatible with the extension's requires.speckit_version constraint
  • A project initialized with specify init (directory with .specify/ folder)

Check Your Version

specify version

First Extension

Start with the bundled GitHub extension:

# 1. Search for the extension
specify extension search github

# 2. Get detailed information
specify extension info github

# 3. Install it
specify extension add github

The extension requires Git and a configured GitHub MCP server. Once those are available, invoke /speckit-github-taskstoissues in GitHub Copilot chat to convert a feature's tasks.md into GitHub issues. This is a chat command, not a terminal command.

The Jira examples below illustrate a separately vetted third-party extension. They assume you have installed it from a reviewed archive or configured your own trusted catalog; Jira is discovery-only in the built-in community catalog.

Finding Extensions

specify extension search searches all active catalogs simultaneously, including the community catalog by default. Results are annotated with their source catalog and install status.

The community catalog is discovery-only. Vet a release before installing it directly or adding it to your own trusted catalog; see the catalog trust model.

Browse All Extensions

specify extension search

Shows all extensions across all active catalogs (default and community by default).

Search by Keyword

# Search for "jira"
specify extension search jira

# Search for "issue tracking"
specify extension search issue

Filter by Tag

# Find all issue-tracking extensions
specify extension search --tag issue-tracking

# Find all Atlassian tools
specify extension search --tag atlassian

Filter by Author

# Extensions by Stats Perform
specify extension search --author "Stats Perform"

Show Verified Only

# Only show verified extensions
specify extension search --verified

Get Extension Details

# Detailed information
specify extension info jira

Shows:

  • Description
  • Requirements
  • Commands provided
  • Hooks available
  • Links (documentation, repository, changelog)
  • Installation status

Installing Extensions

Install from Catalog

# Install a bundled extension by name
specify extension add github

For an extension advertised by an install-enabled catalog, installation will:

  1. Download the advertised archive (bundled extensions use the shipped copy)
  2. Validate the manifest
  3. Check compatibility with your spec-kit version
  4. Install to .specify/extensions/<extension-id>/
  5. Register commands with your coding agent
  6. Scaffold any declared configuration templates without overwriting existing configuration

After vetting Jira, a catalog you control can advertise it as installable:

specify extension add jira

Install from URL

# From GitHub release
specify extension add <extension-name> --from https://github.com/org/spec-kit-ext/archive/refs/tags/v1.0.0.zip

Install from Local Directory (Development)

# For testing or development
specify extension add --dev /path/to/extension

Install a specific catalog version

specify extension info jira --versions
specify extension add jira --version <version>

The requested version must be advertised by the winning install-enabled catalog entry. See the CLI reference for selection rules and option restrictions.

Installation Output

Illustrative output for a Jira release installed from a vetted source:

✓ Extension installed successfully!

Jira Integration (v1.0.0)
  Create Jira Epics, Stories, and Issues from spec-kit artifacts

Provided commands:
  • speckit-jira-specstoissues - Create Jira hierarchy from spec and tasks
  • speckit-jira-discover-fields - Discover Jira custom fields for configuration
  • speckit-jira-sync-status - Sync task completion status to Jira

⚠  Configuration may be required
   Check: .specify/extensions/jira/

Using Extensions

Using Extension Commands

Extensions add skills that appear in GitHub Copilot:

# In GitHub Copilot
> /speckit-jira-specstoissues

Extension Configuration

Most extensions require configuration:

# 1. Find the config file
ls .specify/extensions/jira/

# 2. Copy template to config
cp .specify/extensions/jira/jira-config.template.yml \
   .specify/extensions/jira/jira-config.yml

# 3. Edit configuration
vim .specify/extensions/jira/jira-config.yml

# 4. Use the extension
# (Commands will now work with your config)

Extension Hooks

Some extensions provide hooks that execute after core commands:

Example: Jira extension hooks into /speckit-tasks

# Run core command
> /speckit-tasks

# Output includes:
## Extension Hooks

**Optional Hook**: jira
Command: `/speckit-jira-specstoissues`
Description: Automatically create Jira hierarchy after task generation

Prompt: Create Jira issues from tasks?
To execute: `/speckit-jira-specstoissues`

You can then choose to run the hook or skip it.

Mandatory hooks are surfaced as automatic commands. Current command templates use configured YAML order, skip disabled hooks and hooks with non-empty conditions, and do not consult the reserved auto_execute_hooks setting. See the hook configuration contract for details.

Extensions can also react to coding-agent lifecycle events, such as session start or tool use. Unlike hooks, runtime events execute scripts directly rather than sending Markdown instructions to the coding agent. See Extension runtime events.

Managing Extensions

List Installed Extensions

specify extension list

Output:

Installed Extensions:

  ✓ Jira Integration (v1.0.0)
     Create Jira Epics, Stories, and Issues from spec-kit artifacts
     Commands: 3 | Hooks: 1 | Status: Enabled

Update Extensions

# Check for updates (all extensions)
specify extension update

# Update specific extension
specify extension update jira

Output:

🔄 Checking for updates...

Updates available:

  • jira: 1.0.0 → 1.1.0

Update these extensions? [y/N]:

Disable Extension Temporarily

# Disable without removing
specify extension disable jira

Declarative hooks are marked disabled in .specify/extensions.yml. Native runtime-event configuration is then refreshed on a best-effort basis. A refresh failure produces a warning but can leave a stale native hook active and able to execute. Retry the affected integration with specify integration upgrade <key>. Re-enable the extension with specify extension enable jira.

For the generic integration, disabling also removes owned command or skill files. Other integrations can retain generated files that remain invocable until an integration switch, uninstall, or reconciliation removes them. Disabled extensions are excluded from registry-driven artifact resolution and future integration registration; disabling is not a universal file-removal or execution-blocking mechanism.

Re-enable Extension

specify extension enable jira

✓ Extension 'jira' enabled

Remove Extension

# Remove extension (with confirmation)
specify extension remove jira

# Keep configuration when removing
specify extension remove jira --keep-config

# Force removal (no confirmation)
specify extension remove jira --force

Configuration

Configuration Files

Extensions can have multiple configuration files:

.specify/extensions/jira/
├── jira-config.yml           # Main config (version controlled)
├── local-config.yml         # Local overrides (gitignored)
└── jira-config.template.yml  # Template (reference)

Configuration Layers

Configuration is merged in this order (highest priority last):

  1. Extension defaults (top-level defaults merged with config.defaults, with config.defaults winning on conflicts)
  2. Project config (jira-config.yml)
  3. Local overrides (local-config.yml)
  4. Environment variables (SPECKIT_JIRA_*)

Example: Jira Configuration

Project config (.specify/extensions/jira/jira-config.yml):

project:
  key: "MSATS"

defaults:
  epic:
    labels: ["spec-driven"]

Local override (.specify/extensions/jira/local-config.yml):

project:
  key: "MYTEST"  # Override for local development

Environment variable:

export SPECKIT_JIRA_PROJECT_KEY="DEVTEST"

When the extension uses ConfigManager or equivalent loading, the final resolved config uses DEVTEST from the environment variable. Spec Kit does not automatically inject merged configuration into arbitrary commands or scripts; the extension must load it. YAML ${...} strings are not interpolated by ConfigManager. See Config loading.

Project-Wide Extension Settings

File: .specify/extensions.yml

# Extensions installed in this project
installed:
  - jira
  - linear

# Global settings
settings:
  auto_execute_hooks: true  # Reserved; currently not consulted

# Hook configuration
# Available events: before_specify, after_specify, before_plan, after_plan,
#                   before_tasks, after_tasks, before_implement, after_implement,
#                   before_analyze, after_analyze, before_checklist, after_checklist,
#                   before_clarify, after_clarify, before_constitution, after_constitution,
# Bundled bug extension events (when installed):
#                   before_bug_assess, after_bug_assess, before_bug_fix, after_bug_fix,
#                   before_bug_test, after_bug_test
hooks:
  after_tasks:
    - extension: jira
      command: speckit.jira.specstoissues
      enabled: true
      optional: true
      prompt: "Create Jira issues from tasks?"

See the hook configuration contract for all fields and current execution limitations.

Troubleshooting

Extension Not Found

Error: Extension 'jira' not found in catalog

Solutions:

  1. Check spelling: specify extension search jira
  2. Inspect the active catalogs: specify extension catalog list
  3. Check internet connection
  4. Extension may not be published yet

specify extension search --help displays help; it does not refresh cached catalog data. Catalog caches normally expire after one hour. Python callers can explicitly clear them with ExtensionCatalog.clear_cache().

Configuration Not Found

Error: Jira configuration not found

Solutions:

  1. Check if extension is installed: specify extension list

  2. Create config from template:

    cp .specify/extensions/jira/jira-config.template.yml \
   .specify/extensions/jira/jira-config.yml

  3. Reinstall extension: specify extension remove jira && specify extension add jira

Command Not Available

Issue: Extension command not appearing in coding agent

Solutions:

  1. Check extension is enabled: specify extension list

  2. Restart GitHub Copilot

  3. Check the skill file exists:

    ls .github/skills/speckit-jira-*/SKILL.md

  4. Reinstall extension

Incompatible Version

Error: Extension requires spec-kit >=0.2.0, but you have 0.1.0

Solutions:

  1. Upgrade spec-kit:

    uv tool upgrade specify-cli

  2. Install older version of extension:

    specify extension add <extension-name> --from https://github.com/org/ext/archive/v1.0.0.zip

MCP Tool Not Available

Error: Tool 'jira-mcp-server/epic_create' not found

Solutions:

  1. Check MCP server is installed
  2. Check coding agent MCP configuration
  3. Restart coding agent
  4. Check extension requirements: specify extension info jira

Permission Denied

Error: Permission denied when accessing Jira

Solutions:

  1. Check Jira credentials in MCP server config
  2. Verify project permissions in Jira
  3. Test MCP server connection independently

Best Practices

1. Version Control

Do commit:

  • .specify/extensions.yml (project extension config)
  • .specify/extensions/*/jira-config.yml (project config)

Don't commit:

  • .specify/extensions/.cache/ (catalog cache)
  • .specify/extensions/.backup/ (config backups)
  • .specify/extensions/*/local-config.yml (local overrides)
  • .specify/extensions/.registry (installation state)

Add to .gitignore:

.specify/extensions/.cache/
.specify/extensions/.backup/
.specify/extensions/*/local-config.yml
.specify/extensions/.registry

2. Team Workflows

For teams:

  1. Agree on which extensions to use
  2. Commit extension configuration
  3. Document extension usage in README
  4. Keep extensions updated together

Example README section:

## Extensions

This project uses:
- **jira** (v1.0.0) - Jira integration
  - Config: `.specify/extensions/jira/jira-config.yml`
  - Requires: jira-mcp-server

To install: `specify extension add jira`

3. Local Development

Use local config for development:

# .specify/extensions/jira/local-config.yml
project:
  key: "DEVTEST"  # Your test project

defaults:
  task:
    custom_fields:
      customfield_10002: 1  # Lower story points for testing

4. Environment-Specific Config

Use environment variables for CI/CD:

# .github/workflows/deploy.yml
env:
  SPECKIT_JIRA_PROJECT_KEY: ${{ secrets.JIRA_PROJECT }}

- name: Create Jira Issues
  run: specify extension add jira && ...

5. Extension Updates

Check for updates regularly:

# Weekly or before major releases
specify extension update

Select exact catalog versions for reproducible installation:

specify extension add jira --version 1.0.0

Record the installation command for your team. The installed list in .specify/extensions.yml is not a version-lock mechanism; explicitly running update can install a newer version.

6. Minimal Extensions

Only install extensions you actively use:

  • Reduces complexity
  • Faster command loading
  • Less configuration

7. Documentation

Document extension usage in your project:

# PROJECT.md

## Working with Jira

After creating tasks, sync to Jira:
1. Run `/speckit-tasks` to generate tasks
2. Run `/speckit-jira-specstoissues` to create Jira issues
3. Run `/speckit-jira-sync-status` to update status

FAQ

Q: Can I use multiple extensions at once?

A: Yes! Extensions are designed to work together. Install as many as you need.

Q: Do extensions slow down spec-kit?

A: Extension metadata is read during operations such as listing, installation, and artifact resolution. Hooks can add work around Spec Kit commands, and runtime events can run scripts during coding-agent lifecycle events. Their cost depends on the installed extensions and configured behavior.

Q: Can I create private extensions?

A: Yes. Install with --dev or --from and keep private. Public catalog submission is optional.

Q: How do I know if an extension is safe?

A: A verified badge is not a code-audit guarantee. Spec Kit maintainers do not review, audit, endorse, or support independently maintained extension code. You must vet the source and release archive before installing; use extensions at your own discretion.

Q: Can extensions modify spec-kit core?

A: Extensions contribute commands, templates, scripts, hooks, and runtime events without changing Spec Kit's source code. Their commands and hooks can edit project files under their documented behavior and the project's governance; see Specification artifact maintenance.

Q: What happens if two extensions have the same command name?

A: Namespaced commands (speckit.{extension}.{command}) reduce conflicts. Installation rejects exact command-name or alias collisions with installed extensions, and normalized output-name collisions with core commands. Resolution priority determines precedence for contributed artifacts such as templates; it does not allow conflicting command names to be installed. Use specify extension set-priority to change artifact resolution priority.

Q: Can I contribute to existing extensions?

A: Yes! Most extensions are open source. Check the repository link in specify extension info {extension}.

Q: How do I report extension bugs?

A: Go to the extension's repository (shown in specify extension info) and create an issue.

Q: Can extensions work offline?

A: Once installed, extensions work offline. However, some extensions may require internet for their functionality (e.g., Jira requires Jira API access).

Q: How do I backup my extension configuration?

A: Extension configs are in .specify/extensions/{extension}/. Back up this directory or commit configs to git.

Support

Last Updated: 2026-01-28 Spec Kit Version: 0.1.0

Agent invocation examples on this page use GitHub Copilot's default skills syntax (/speckit-*). For other integrations and modes, see Command invocation.

See also

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