feat: Git extension stage 1 — bundled extensions/git with hooks on all core commands

extensions/EXTENSION-API-REFERENCE.md

@@ -108,7 +108,7 @@ defaults:                # Optional, default configuration values
 #### `hooks`
 
 - **Type**: object
-- **Keys**: Event names (e.g., `after_specify`, `after_plan`, `after_tasks`, `after_implement`, `before_commit`)
+- **Keys**: Event names (e.g., `after_specify`, `after_plan`, `after_tasks`, `after_implement`, `before_analyze`)
 - **Description**: Hooks that execute at lifecycle events
 - **Events**: Defined by core spec-kit commands
 
@@ -559,8 +559,16 @@ Standard events (defined by core):
 - `after_tasks` - After task generation
 - `before_implement` - Before implementation
 - `after_implement` - After implementation
-- `before_commit` - Before git commit *(planned - not yet wired into core templates)*
-- `after_commit` - After git commit *(planned - not yet wired into core templates)*
+- `before_analyze` - Before cross-artifact analysis
+- `after_analyze` - After cross-artifact analysis
+- `before_checklist` - Before checklist generation
+- `after_checklist` - After checklist generation
+- `before_clarify` - Before spec clarification
+- `after_clarify` - After spec clarification
+- `before_constitution` - Before constitution update
+- `after_constitution` - After constitution update
+- `before_taskstoissues` - Before tasks-to-issues conversion
+- `after_taskstoissues` - After tasks-to-issues conversion
 
 ### Hook Configuration
 

extensions/EXTENSION-DEVELOPMENT-GUIDE.md

@@ -177,9 +177,9 @@ Compatibility requirements.
 
 What the extension provides.
 
-**Required sub-fields**:
+**Optional sub-fields**:
 
-- `commands`: Array of command objects (must have at least one)
+- `commands`: Array of command objects (at least one command or hook is required)
 
 **Command object**:
 
@@ -196,12 +196,19 @@ Integration hooks for automatic execution.
 
 Available hook points:
 
-- `after_tasks`: After `/speckit.tasks` completes
-- `after_implement`: After `/speckit.implement` completes (future)
+- `before_specify` / `after_specify`: Before/after specification generation
+- `before_plan` / `after_plan`: Before/after implementation planning
+- `before_tasks` / `after_tasks`: Before/after task generation
+- `before_implement` / `after_implement`: Before/after implementation
+- `before_analyze` / `after_analyze`: Before/after cross-artifact analysis
+- `before_checklist` / `after_checklist`: Before/after checklist generation
+- `before_clarify` / `after_clarify`: Before/after spec clarification
+- `before_constitution` / `after_constitution`: Before/after constitution update
+- `before_taskstoissues` / `after_taskstoissues`: Before/after tasks-to-issues conversion
 
 Hook object:
 
-- `command`: Command to execute (must be in `provides.commands`)
+- `command`: Command to execute (typically from `provides.commands`, but can reference any registered command)
 - `optional`: If true, prompt user before executing
 - `prompt`: Prompt text for optional hooks
 - `description`: Hook description

extensions/EXTENSION-USER-GUIDE.md

@@ -403,8 +403,10 @@ settings:
 
 # Hook configuration
 # Available events: before_specify, after_specify, before_plan, after_plan,
-#                   before_tasks, after_tasks, before_implement, after_implement
-# Planned (not yet wired into core templates): before_commit, after_commit
+#                   before_tasks, after_tasks, before_implement, after_implement,
+#                   before_analyze, after_analyze, before_checklist, after_checklist,
+#                   before_clarify, after_clarify, before_constitution, after_constitution,
+#                   before_taskstoissues, after_taskstoissues
 hooks:
   after_tasks:
     - extension: jira

extensions/catalog.json

@@ -1,8 +1,23 @@
 {
   "schema_version": "1.0",
-  "updated_at": "2026-03-10T00:00:00Z",
+  "updated_at": "2026-04-06T00:00:00Z",
   "catalog_url": "https://raw.githubusercontent.com/github/spec-kit/main/extensions/catalog.json",
   "extensions": {
+    "git": {
+      "name": "Git Branching Workflow",
+      "id": "git",
+      "version": "1.0.0",
+      "description": "Feature branch creation, numbering (sequential/timestamp), validation, and Git remote detection",
+      "author": "spec-kit-core",
+      "repository": "https://github.com/github/spec-kit",
+      "download_url": "https://github.com/github/spec-kit/releases/download/ext-git-v1.0.0/git.zip",
+      "tags": [
+        "git",
+        "branching",
+        "workflow",
+        "core"
+      ]
+    },
     "selftest": {
       "name": "Spec Kit Self-Test Utility",
       "id": "selftest",

extensions/git/README.md

@@ -0,0 +1,99 @@
+# Git Branching Workflow Extension
+
+Git repository initialization, feature branch creation, numbering (sequential/timestamp), validation, remote detection, and auto-commit for Spec Kit.
+
+## Overview
+
+This extension provides Git operations as an optional, self-contained module. It manages:
+
+- **Repository initialization** with configurable commit messages
+- **Feature branch creation** with sequential (`001-feature-name`) or timestamp (`20260319-143022-feature-name`) numbering
+- **Branch validation** to ensure branches follow naming conventions
+- **Git remote detection** for GitHub integration (e.g., issue creation)
+- **Auto-commit** after core commands (configurable per-command with custom messages)
+
+## Commands
+
+| Command | Description |
+|---------|-------------|
+| `speckit.git.initialize` | Initialize a Git repository with a configurable commit message |
+| `speckit.git.feature` | Create a feature branch with sequential or timestamp numbering |
+| `speckit.git.validate` | Validate current branch follows feature branch naming conventions |
+| `speckit.git.remote` | Detect Git remote URL for GitHub integration |
+| `speckit.git.commit` | Auto-commit changes (configurable per-command enable/disable and messages) |
+
+## Hooks
+
+| Event | Command | Optional | Description |
+|-------|---------|----------|-------------|
+| `before_constitution` | `speckit.git.initialize` | No | Init git repo before constitution |
+| `before_specify` | `speckit.git.feature` | No | Create feature branch before specification |
+| `before_clarify` | `speckit.git.commit` | Yes | Commit outstanding changes before clarification |
+| `before_plan` | `speckit.git.commit` | Yes | Commit outstanding changes before planning |
+| `before_tasks` | `speckit.git.commit` | Yes | Commit outstanding changes before task generation |
+| `before_implement` | `speckit.git.commit` | Yes | Commit outstanding changes before implementation |
+| `before_checklist` | `speckit.git.commit` | Yes | Commit outstanding changes before checklist |
+| `before_analyze` | `speckit.git.commit` | Yes | Commit outstanding changes before analysis |
+| `before_taskstoissues` | `speckit.git.commit` | Yes | Commit outstanding changes before issue sync |
+| `after_constitution` | `speckit.git.commit` | Yes | Auto-commit after constitution update |
+| `after_specify` | `speckit.git.commit` | Yes | Auto-commit after specification |
+| `after_clarify` | `speckit.git.commit` | Yes | Auto-commit after clarification |
+| `after_plan` | `speckit.git.commit` | Yes | Auto-commit after planning |
+| `after_tasks` | `speckit.git.commit` | Yes | Auto-commit after task generation |
+| `after_implement` | `speckit.git.commit` | Yes | Auto-commit after implementation |
+| `after_checklist` | `speckit.git.commit` | Yes | Auto-commit after checklist |
+| `after_analyze` | `speckit.git.commit` | Yes | Auto-commit after analysis |
+| `after_taskstoissues` | `speckit.git.commit` | Yes | Auto-commit after issue sync |
+
+## Configuration
+
+Configuration is stored in `.specify/extensions/git/git-config.yml`:
+
+```yaml
+# Branch numbering strategy: "sequential" or "timestamp"
+branch_numbering: sequential
+
+# Custom commit message for git init
+init_commit_message: "[Spec Kit] Initial commit"
+
+# Auto-commit per command (all disabled by default)
+auto_commit:
+  default: false
+  after_specify:
+    enabled: true
+    message: "[Spec Kit] Add specification"
+```
+
+## Installation
+
+```bash
+# Install the bundled git extension (no network required)
+specify extension add git
+```
+
+## Disabling
+
+```bash
+# Disable the git extension (spec creation continues without branching)
+specify extension disable git
+
+# Re-enable it
+specify extension enable git
+```
+
+## Graceful Degradation
+
+When Git is not installed or the directory is not a Git repository:
+- Spec directories are still created under `specs/`
+- Branch creation is skipped with a warning
+- Branch validation is skipped with a warning
+- Remote detection returns empty results
+
+## Scripts
+
+The extension bundles cross-platform scripts:
+
+- `scripts/bash/create-new-feature.sh` — Bash implementation
+- `scripts/bash/git-common.sh` — Shared Git utilities (Bash)
+- `scripts/powershell/create-new-feature.ps1` — PowerShell implementation
+- `scripts/powershell/git-common.ps1` — Shared Git utilities (PowerShell)

extensions/git/commands/speckit.git.commit.md

@@ -0,0 +1,48 @@
+---
+description: "Auto-commit changes after a Spec Kit command completes"
+---
+
+# Auto-Commit Changes
+
+Automatically stage and commit all changes after a Spec Kit command completes.
+
+## Behavior
+
+This command is invoked as a hook after (or before) core commands. It:
+
+1. Determines the event name from the hook context (e.g., if invoked as an `after_specify` hook, the event is `after_specify`; if `before_plan`, the event is `before_plan`)
+2. Checks `.specify/extensions/git/git-config.yml` for the `auto_commit` section
+3. Looks up the specific event key to see if auto-commit is enabled
+4. Falls back to `auto_commit.default` if no event-specific key exists
+5. Uses the per-command `message` if configured, otherwise a default message
+6. If enabled and there are uncommitted changes, runs `git add .` + `git commit`
+
+## Execution
+
+Determine the event name from the hook that triggered this command, then run the script:
+
+- **Bash**: `.specify/extensions/git/scripts/bash/auto-commit.sh <event_name>`
+- **PowerShell**: `.specify/extensions/git/scripts/powershell/auto-commit.ps1 <event_name>`
+
+Replace `<event_name>` with the actual hook event (e.g., `after_specify`, `before_plan`, `after_implement`).
+
+## Configuration
+
+In `.specify/extensions/git/git-config.yml`:
+
+```yaml
+auto_commit:
+  default: false          # Global toggle — set true to enable for all commands
+  after_specify:
+    enabled: true          # Override per-command
+    message: "[Spec Kit] Add specification"
+  after_plan:
+    enabled: false
+    message: "[Spec Kit] Add implementation plan"
+```
+
+## Graceful Degradation
+
+- If Git is not available or the current directory is not a repository: skips with a warning
+- If no config file exists: skips (disabled by default)
+- If no changes to commit: skips with a message

extensions/git/commands/speckit.git.feature.md

@@ -0,0 +1,66 @@
+---
+description: "Create a feature branch with sequential or timestamp numbering"
+---
+
+# Create Feature Branch
+
+Create a new feature branch for the given specification.
+
+## User Input
+
+```text
+$ARGUMENTS
+```
+
+You **MUST** consider the user input before proceeding (if not empty).
+
+## Prerequisites
+
+- Verify Git is available by running `git rev-parse --is-inside-work-tree 2>/dev/null`
+- If Git is not available, warn the user and skip branch creation (spec directory will still be created)
+
+## Branch Numbering Mode
+
+Determine the branch numbering strategy by checking configuration in this order:
+
+1. Check `.specify/extensions/git/git-config.yml` for `branch_numbering` value
+2. Check `.specify/init-options.json` for `branch_numbering` value (backward compatibility)
+3. Default to `sequential` if neither exists
+
+## Execution
+
+Generate a concise short name (2-4 words) for the branch:
+- Analyze the feature description and extract the most meaningful keywords
+- Use action-noun format when possible (e.g., "add-user-auth", "fix-payment-bug")
+- Preserve technical terms and acronyms (OAuth2, API, JWT, etc.)
+
+Run the appropriate script based on your platform:
+
+- **Bash**: `.specify/extensions/git/scripts/bash/create-new-feature.sh --json --short-name "<short-name>" "<feature description>"`
+- **Bash (timestamp)**: `.specify/extensions/git/scripts/bash/create-new-feature.sh --json --timestamp --short-name "<short-name>" "<feature description>"`
+- **PowerShell**: `.specify/extensions/git/scripts/powershell/create-new-feature.ps1 -Json -ShortName "<short-name>" "<feature description>"`
+- **PowerShell (timestamp)**: `.specify/extensions/git/scripts/powershell/create-new-feature.ps1 -Json -Timestamp -ShortName "<short-name>" "<feature description>"`
+
+**IMPORTANT**:
+- Do NOT pass `--number` — the script determines the correct next number automatically
+- Always include the JSON flag (`--json` for Bash, `-Json` for PowerShell) so the output can be parsed reliably
+- You must only ever run this script once per feature
+- The JSON output will contain BRANCH_NAME and SPEC_FILE paths
+
+If the extension scripts are not found at the `.specify/extensions/git/` path, fall back to:
+- **Bash**: `scripts/bash/create-new-feature.sh`
+- **PowerShell**: `scripts/powershell/create-new-feature.ps1`
+
+## Graceful Degradation
+
+If Git is not installed or the current directory is not a Git repository:
+- The script will still create the spec directory under `specs/`
+- A warning will be printed: `[specify] Warning: Git repository not detected; skipped branch creation`
+- The workflow continues normally without branch creation
+
+## Output
+
+The script outputs JSON with:
+- `BRANCH_NAME`: The created branch name (e.g., `003-user-auth` or `20260319-143022-user-auth`)
+- `SPEC_FILE`: Path to the created spec file
+- `FEATURE_NUM`: The numeric or timestamp prefix used

extensions/git/commands/speckit.git.initialize.md

@@ -0,0 +1,49 @@
+---
+description: "Initialize a Git repository with an initial commit"
+---
+
+# Initialize Git Repository
+
+Initialize a Git repository in the current project directory if one does not already exist.
+
+## Execution
+
+Run the appropriate script from the project root:
+
+- **Bash**: `.specify/extensions/git/scripts/bash/initialize-repo.sh`
+- **PowerShell**: `.specify/extensions/git/scripts/powershell/initialize-repo.ps1`
+
+If the extension scripts are not found, fall back to:
+- **Bash**: `git init && git add . && git commit -m "Initial commit from Specify template"`
+- **PowerShell**: `git init; git add .; git commit -m "Initial commit from Specify template"`
+
+The script handles all checks internally:
+- Skips if Git is not available
+- Skips if already inside a Git repository
+- Runs `git init`, `git add .`, and `git commit` with an initial commit message
+
+## Customization
+
+Replace the script to add project-specific Git initialization steps:
+- Custom `.gitignore` templates
+- Default branch naming (`git config init.defaultBranch`)
+- Git LFS setup
+- Git hooks installation
+- Commit signing configuration
+- Git Flow initialization
+
+## Output
+
+On success:
+- `✓ Git repository initialized`
+
+## Graceful Degradation
+
+If Git is not installed:
+- Warn the user
+- Skip repository initialization
+- The project continues to function without Git (specs can still be created under `specs/`)
+
+If Git is installed but `git init`, `git add .`, or `git commit` fails:
+- Surface the error to the user
+- Stop this command rather than continuing with a partially initialized repository