feat: Git extension stage 1 — bundled extensions/git with hooks on all core commands (#1941)

* feat: add git extension with hooks on all core commands - Create extensions/git/ with 5 commands: initialize, feature, validate, remote, commit - 18 hooks covering before/after for all 9 core commands - Scripts: create-new-feature, initialize-repo, auto-commit, git-common (bash + powershell) - Configurable: branch_numbering, init_commit_message, per-command auto-commit with custom messages - Add hooks to analyze, checklist, clarify, constitution, taskstoissues command templates - Allow hooks-only extensions (no commands required) - Bundle extension in wheel via pyproject.toml force-include - Resolve bundled extensions locally before catalog lookup - Remove planned-but-unimplemented before/after_commit hook refs - Update extension docs (API ref, dev guide, user guide) - 37 new tests covering manifest, install, all scripts (bash+pwsh), config reading, graceful degradation Stage 1: opt-in via 'specify extension add git'. No auto-install, no changes to specify.md or core git init code. Refs: #841, #1382, #1066, #1791, #1191 * fix: set git identity env vars in extension tests for CI runners * fix: address PR review comments - Fix commands property KeyError for hooks-only extensions - Fix has_git() operator precedence in git-common.sh - Align default commit message to '[Spec Kit] Initial commit' across config-template, extension.yml defaults, and both init scripts - Update README to reflect all 5 commands and 18 hooks * fix: address second round of PR review comments - Add type validation for provides.commands (must be list) and hooks (must be dict) in manifest _validate() - Tighten malformed timestamp detection in git-common.sh to catch 7-digit dates without trailing slug (e.g. 2026031-143022) - Pass REPO_ROOT to has_git/Test-HasGit in create-new-feature scripts - Fix initialize command docs: surface errors on git failures, only skip when git is not installed - Fix commit command docs: 'skips with a warning' not 'silently' - Add tests for commands:null and hooks:list rejection * fix: address third round of PR review comments - Remove scripts frontmatter from command files (CommandRegistrar rewrites ../../scripts/ to .specify/scripts/ which points at core scripts, not extension scripts) - Update speckit.git.commit command to derive event name from hook context rather than using a static example - Clarify that hook argument passthrough works via AI agent context (the agent carries conversation state including user's original feature description) * fix: address fourth round of PR review comments - Validate extension_id against ^[a-z0-9-]+$ in _locate_bundled_extension to prevent path traversal (security fix) - Move defaults under config.defaults in extension.yml to match ConfigManager._get_extension_defaults() schema - Ship git-config.yml in extension directory so it's copied during install (provides.config template isn't materialized by ExtensionManager) - Condition handling in hook templates: intentionally matches existing pattern from specify/plan/tasks/implement templates (not a new issue) * fix: add --allow-empty to git commit in initialize-repo scripts Ensures git init succeeds even on empty repos where nothing has been staged yet. * fix: resolve display names to bundled extensions before catalog download When 'specify extension add "Git Branching Workflow"' is used with a display name instead of the ID, the catalog resolver now runs first to map the name to an ID, then checks bundled extensions again with the resolved ID before falling back to network download. Also noted: EXECUTE_COMMAND_INVOCATION and condition handling match the existing pattern in specify/plan/tasks/implement templates (pre-existing, not introduced by this PR). * fix: handle before_/after_ prefixes in auto-commit message derivation - Strip both before_ and after_ prefixes when deriving command name (fixes misleading 'Auto-commit after before_plan' messages) - Include phase (before/after) in default commit messages - Clarify README config example is an override, not default behavior * fix: use portable grep -qw for word boundary in create-new-feature.sh BSD grep (macOS) doesn't support \b as a word boundary. Replace with grep -qw which is POSIX-portable. * fix: validate hook values, numeric --number, and PS warning routing - Validate each hook value is a dict with a 'command' field during manifest _validate() (prevents crash at install time) - Validate --number is a non-negative integer in bash create-new-feature (clear error instead of cryptic shell arithmetic failure) - Route PowerShell no-git warning to stderr in JSON mode so stdout stays valid JSON --------- Co-authored-by: Manfred Riem <15701806+mnriem@users.noreply.github.com>
2026-07-03 12:28:06 +08:00 · 2026-04-07 08:39:35 -05:00
parent aad6f68ae5
commit 1a9e4d1d8d
33 changed files with 3108 additions and 54 deletions
--- a/extensions/EXTENSION-API-REFERENCE.md
+++ b/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

--- a/extensions/EXTENSION-DEVELOPMENT-GUIDE.md
+++ b/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
--- a/extensions/EXTENSION-USER-GUIDE.md
+++ b/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
--- a/extensions/catalog.json
+++ b/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",
--- a/extensions/git/README.md
+++ b/extensions/git/README.md
@@ -0,0 +1,100 @@
+# 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)
+# Example: enable auto-commit after specify
+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)
--- a/extensions/git/commands/speckit.git.commit.md
+++ b/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
--- a/extensions/git/commands/speckit.git.feature.md
+++ b/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
--- a/extensions/git/commands/speckit.git.initialize.md
+++ b/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
--- a/extensions/git/commands/speckit.git.remote.md
+++ b/extensions/git/commands/speckit.git.remote.md
@@ -0,0 +1,45 @@
+---
+description: "Detect Git remote URL for GitHub integration"
+---
+
+# Detect Git Remote URL
+
+Detect the Git remote URL for integration with GitHub services (e.g., issue creation).
+
+## Prerequisites
+
+- Check if Git is available by running `git rev-parse --is-inside-work-tree 2>/dev/null`
+- If Git is not available, output a warning and return empty:
+  ```
+  [specify] Warning: Git repository not detected; cannot determine remote URL
+  ```
+
+## Execution
+
+Run the following command to get the remote URL:
+
+```bash
+git config --get remote.origin.url
+```
+
+## Output
+
+Parse the remote URL and determine:
+
+1. **Repository owner**: Extract from the URL (e.g., `github` from `https://github.com/github/spec-kit.git`)
+2. **Repository name**: Extract from the URL (e.g., `spec-kit` from `https://github.com/github/spec-kit.git`)
+3. **Is GitHub**: Whether the remote points to a GitHub repository
+
+Supported URL formats:
+- HTTPS: `https://github.com/<owner>/<repo>.git`
+- SSH: `git@github.com:<owner>/<repo>.git`
+
+> [!CAUTION]
+> ONLY report a GitHub repository if the remote URL actually points to github.com.
+> Do NOT assume the remote is GitHub if the URL format doesn't match.
+
+## Graceful Degradation
+
+If Git is not installed, the directory is not a Git repository, or no remote is configured:
+- Return an empty result
+- Do NOT error — other workflows should continue without Git remote information
--- a/extensions/git/commands/speckit.git.validate.md
+++ b/extensions/git/commands/speckit.git.validate.md
@@ -0,0 +1,49 @@
+---
+description: "Validate current branch follows feature branch naming conventions"
+---
+
+# Validate Feature Branch
+
+Validate that the current Git branch follows the expected feature branch naming conventions.
+
+## Prerequisites
+
+- Check if Git is available by running `git rev-parse --is-inside-work-tree 2>/dev/null`
+- If Git is not available, output a warning and skip validation:
+  ```
+  [specify] Warning: Git repository not detected; skipped branch validation
+  ```
+
+## Validation Rules
+
+Get the current branch name:
+
+```bash
+git rev-parse --abbrev-ref HEAD
+```
+
+The branch name must match one of these patterns:
+
+1. **Sequential**: `^[0-9]{3,}-` (e.g., `001-feature-name`, `042-fix-bug`, `1000-big-feature`)
+2. **Timestamp**: `^[0-9]{8}-[0-9]{6}-` (e.g., `20260319-143022-feature-name`)
+
+## Execution
+
+If on a feature branch (matches either pattern):
+- Output: `✓ On feature branch: <branch-name>`
+- Check if the corresponding spec directory exists under `specs/`:
+  - For sequential branches, look for `specs/<prefix>-*` where prefix matches the numeric portion
+  - For timestamp branches, look for `specs/<prefix>-*` where prefix matches the `YYYYMMDD-HHMMSS` portion
+- If spec directory exists: `✓ Spec directory found: <path>`
+- If spec directory missing: `⚠ No spec directory found for prefix <prefix>`
+
+If NOT on a feature branch:
+- Output: `✗ Not on a feature branch. Current branch: <branch-name>`
+- Output: `Feature branches should be named like: 001-feature-name or 20260319-143022-feature-name`
+
+## Graceful Degradation
+
+If Git is not installed or the directory is not a Git repository:
+- Check the `SPECIFY_FEATURE` environment variable as a fallback
+- If set, validate that value against the naming patterns
+- If not set, skip validation with a warning
--- a/extensions/git/config-template.yml
+++ b/extensions/git/config-template.yml
@@ -0,0 +1,62 @@
+# Git Branching Workflow Extension Configuration
+# Copied to .specify/extensions/git/git-config.yml on install
+
+# Branch numbering strategy: "sequential" (001, 002, ...) or "timestamp" (YYYYMMDD-HHMMSS)
+branch_numbering: sequential
+
+# Commit message used by `git commit` during repository initialization
+init_commit_message: "[Spec Kit] Initial commit"
+
+# Auto-commit before/after core commands.
+# Set "default" to enable for all commands, then override per-command.
+# Each key can be true/false. Message is customizable per-command.
+auto_commit:
+  default: false
+  before_clarify:
+    enabled: false
+    message: "[Spec Kit] Save progress before clarification"
+  before_plan:
+    enabled: false
+    message: "[Spec Kit] Save progress before planning"
+  before_tasks:
+    enabled: false
+    message: "[Spec Kit] Save progress before task generation"
+  before_implement:
+    enabled: false
+    message: "[Spec Kit] Save progress before implementation"
+  before_checklist:
+    enabled: false
+    message: "[Spec Kit] Save progress before checklist"
+  before_analyze:
+    enabled: false
+    message: "[Spec Kit] Save progress before analysis"
+  before_taskstoissues:
+    enabled: false
+    message: "[Spec Kit] Save progress before issue sync"
+  after_constitution:
+    enabled: false
+    message: "[Spec Kit] Add project constitution"
+  after_specify:
+    enabled: false
+    message: "[Spec Kit] Add specification"
+  after_clarify:
+    enabled: false
+    message: "[Spec Kit] Clarify specification"
+  after_plan:
+    enabled: false
+    message: "[Spec Kit] Add implementation plan"
+  after_tasks:
+    enabled: false
+    message: "[Spec Kit] Add tasks"
+  after_implement:
+    enabled: false
+    message: "[Spec Kit] Implementation progress"
+  after_checklist:
+    enabled: false
+    message: "[Spec Kit] Add checklist"
+  after_analyze:
+    enabled: false
+    message: "[Spec Kit] Add analysis report"
+  after_taskstoissues:
+    enabled: false
+    message: "[Spec Kit] Sync tasks to issues"
--- a/extensions/git/extension.yml
+++ b/extensions/git/extension.yml
@@ -0,0 +1,140 @@
+schema_version: "1.0"
+
+extension:
+  id: git
+  name: "Git Branching Workflow"
+  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
+  license: MIT
+
+requires:
+  speckit_version: ">=0.2.0"
+  tools:
+    - name: git
+      required: false
+
+provides:
+  commands:
+    - name: speckit.git.feature
+      file: commands/speckit.git.feature.md
+      description: "Create a feature branch with sequential or timestamp numbering"
+    - name: speckit.git.validate
+      file: commands/speckit.git.validate.md
+      description: "Validate current branch follows feature branch naming conventions"
+    - name: speckit.git.remote
+      file: commands/speckit.git.remote.md
+      description: "Detect Git remote URL for GitHub integration"
+    - name: speckit.git.initialize
+      file: commands/speckit.git.initialize.md
+      description: "Initialize a Git repository with an initial commit"
+    - name: speckit.git.commit
+      file: commands/speckit.git.commit.md
+      description: "Auto-commit changes after a Spec Kit command completes"
+
+  config:
+    - name: "git-config.yml"
+      template: "config-template.yml"
+      description: "Git branching configuration"
+      required: false
+
+hooks:
+  before_constitution:
+    command: speckit.git.initialize
+    optional: false
+    description: "Initialize Git repository before constitution setup"
+  before_specify:
+    command: speckit.git.feature
+    optional: false
+    description: "Create feature branch before specification"
+  before_clarify:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit outstanding changes before clarification?"
+    description: "Auto-commit before spec clarification"
+  before_plan:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit outstanding changes before planning?"
+    description: "Auto-commit before implementation planning"
+  before_tasks:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit outstanding changes before task generation?"
+    description: "Auto-commit before task generation"
+  before_implement:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit outstanding changes before implementation?"
+    description: "Auto-commit before implementation"
+  before_checklist:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit outstanding changes before checklist?"
+    description: "Auto-commit before checklist generation"
+  before_analyze:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit outstanding changes before analysis?"
+    description: "Auto-commit before analysis"
+  before_taskstoissues:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit outstanding changes before issue sync?"
+    description: "Auto-commit before tasks-to-issues conversion"
+  after_constitution:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit constitution changes?"
+    description: "Auto-commit after constitution update"
+  after_specify:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit specification changes?"
+    description: "Auto-commit after specification"
+  after_clarify:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit clarification changes?"
+    description: "Auto-commit after spec clarification"
+  after_plan:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit plan changes?"
+    description: "Auto-commit after implementation planning"
+  after_tasks:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit task changes?"
+    description: "Auto-commit after task generation"
+  after_implement:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit implementation changes?"
+    description: "Auto-commit after implementation"
+  after_checklist:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit checklist changes?"
+    description: "Auto-commit after checklist generation"
+  after_analyze:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit analysis results?"
+    description: "Auto-commit after analysis"
+  after_taskstoissues:
+    command: speckit.git.commit
+    optional: true
+    prompt: "Commit after syncing issues?"
+    description: "Auto-commit after tasks-to-issues conversion"
+
+tags:
+  - "git"
+  - "branching"
+  - "workflow"
+
+config:
+  defaults:
+    branch_numbering: sequential
+    init_commit_message: "[Spec Kit] Initial commit"
--- a/extensions/git/git-config.yml
+++ b/extensions/git/git-config.yml
@@ -0,0 +1,62 @@
+# Git Branching Workflow Extension Configuration
+# Copied to .specify/extensions/git/git-config.yml on install
+
+# Branch numbering strategy: "sequential" (001, 002, ...) or "timestamp" (YYYYMMDD-HHMMSS)
+branch_numbering: sequential
+
+# Commit message used by `git commit` during repository initialization
+init_commit_message: "[Spec Kit] Initial commit"
+
+# Auto-commit before/after core commands.
+# Set "default" to enable for all commands, then override per-command.
+# Each key can be true/false. Message is customizable per-command.
+auto_commit:
+  default: false
+  before_clarify:
+    enabled: false
+    message: "[Spec Kit] Save progress before clarification"
+  before_plan:
+    enabled: false
+    message: "[Spec Kit] Save progress before planning"
+  before_tasks:
+    enabled: false
+    message: "[Spec Kit] Save progress before task generation"
+  before_implement:
+    enabled: false
+    message: "[Spec Kit] Save progress before implementation"
+  before_checklist:
+    enabled: false
+    message: "[Spec Kit] Save progress before checklist"
+  before_analyze:
+    enabled: false
+    message: "[Spec Kit] Save progress before analysis"
+  before_taskstoissues:
+    enabled: false
+    message: "[Spec Kit] Save progress before issue sync"
+  after_constitution:
+    enabled: false
+    message: "[Spec Kit] Add project constitution"
+  after_specify:
+    enabled: false
+    message: "[Spec Kit] Add specification"
+  after_clarify:
+    enabled: false
+    message: "[Spec Kit] Clarify specification"
+  after_plan:
+    enabled: false
+    message: "[Spec Kit] Add implementation plan"
+  after_tasks:
+    enabled: false
+    message: "[Spec Kit] Add tasks"
+  after_implement:
+    enabled: false
+    message: "[Spec Kit] Implementation progress"
+  after_checklist:
+    enabled: false
+    message: "[Spec Kit] Add checklist"
+  after_analyze:
+    enabled: false
+    message: "[Spec Kit] Add analysis report"
+  after_taskstoissues:
+    enabled: false
+    message: "[Spec Kit] Sync tasks to issues"
--- a/extensions/git/scripts/bash/auto-commit.sh
+++ b/extensions/git/scripts/bash/auto-commit.sh
@@ -0,0 +1,140 @@
+#!/usr/bin/env bash
+# Git extension: auto-commit.sh
+# Automatically commit changes after a Spec Kit command completes.
+# Checks per-command config keys in git-config.yml before committing.
+#
+# Usage: auto-commit.sh <event_name>
+#   e.g.: auto-commit.sh after_specify
+
+set -e
+
+EVENT_NAME="${1:-}"
+if [ -z "$EVENT_NAME" ]; then
+    echo "Usage: $0 <event_name>" >&2
+    exit 1
+fi
+
+SCRIPT_DIR="$(CDPATH="" cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+_find_project_root() {
+    local dir="$1"
+    while [ "$dir" != "/" ]; do
+        if [ -d "$dir/.specify" ] || [ -d "$dir/.git" ]; then
+            echo "$dir"
+            return 0
+        fi
+        dir="$(dirname "$dir")"
+    done
+    return 1
+}
+
+REPO_ROOT=$(_find_project_root "$SCRIPT_DIR") || REPO_ROOT="$(pwd)"
+cd "$REPO_ROOT"
+
+# Check if git is available
+if ! command -v git >/dev/null 2>&1; then
+    echo "[specify] Warning: Git not found; skipped auto-commit" >&2
+    exit 0
+fi
+
+if ! git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
+    echo "[specify] Warning: Not a Git repository; skipped auto-commit" >&2
+    exit 0
+fi
+
+# Read per-command config from git-config.yml
+_config_file="$REPO_ROOT/.specify/extensions/git/git-config.yml"
+_enabled=false
+_commit_msg=""
+
+if [ -f "$_config_file" ]; then
+    # Parse the auto_commit section for this event.
+    # Look for auto_commit.<event_name>.enabled and .message
+    # Also check auto_commit.default as fallback.
+    _in_auto_commit=false
+    _in_event=false
+    _default_enabled=false
+
+    while IFS= read -r _line; do
+        # Detect auto_commit: section
+        if echo "$_line" | grep -q '^auto_commit:'; then
+            _in_auto_commit=true
+            _in_event=false
+            continue
+        fi
+
+        # Exit auto_commit section on next top-level key
+        if $_in_auto_commit && echo "$_line" | grep -Eq '^[a-z]'; then
+            break
+        fi
+
+        if $_in_auto_commit; then
+            # Check default key
+            if echo "$_line" | grep -Eq "^[[:space:]]+default:[[:space:]]"; then
+                _val=$(echo "$_line" | sed 's/^[^:]*:[[:space:]]*//' | tr -d '[:space:]' | tr '[:upper:]' '[:lower:]')
+                [ "$_val" = "true" ] && _default_enabled=true
+            fi
+
+            # Detect our event subsection
+            if echo "$_line" | grep -Eq "^[[:space:]]+${EVENT_NAME}:"; then
+                _in_event=true
+                continue
+            fi
+
+            # Inside our event subsection
+            if $_in_event; then
+                # Exit on next sibling key (same indent level as event name)
+                if echo "$_line" | grep -Eq '^[[:space:]]{2}[a-z]' && ! echo "$_line" | grep -Eq '^[[:space:]]{4}'; then
+                    _in_event=false
+                    continue
+                fi
+                if echo "$_line" | grep -Eq '[[:space:]]+enabled:'; then
+                    _val=$(echo "$_line" | sed 's/^[^:]*:[[:space:]]*//' | tr -d '[:space:]' | tr '[:upper:]' '[:lower:]')
+                    [ "$_val" = "true" ] && _enabled=true
+                    [ "$_val" = "false" ] && _enabled=false
+                fi
+                if echo "$_line" | grep -Eq '[[:space:]]+message:'; then
+                    _commit_msg=$(echo "$_line" | sed 's/^[^:]*:[[:space:]]*//' | sed 's/^["'\'']//' | sed 's/["'\'']*$//')
+                fi
+            fi
+        fi
+    done < "$_config_file"
+
+    # If event-specific key not found, use default
+    if [ "$_enabled" = "false" ] && [ "$_default_enabled" = "true" ]; then
+        # Only use default if the event wasn't explicitly set to false
+        # Check if event section existed at all
+        if ! grep -q "^[[:space:]]*${EVENT_NAME}:" "$_config_file" 2>/dev/null; then
+            _enabled=true
+        fi
+    fi
+else
+    # No config file — auto-commit disabled by default
+    exit 0
+fi
+
+if [ "$_enabled" != "true" ]; then
+    exit 0
+fi
+
+# Check if there are changes to commit
+if git diff --quiet HEAD 2>/dev/null && git diff --cached --quiet 2>/dev/null && [ -z "$(git ls-files --others --exclude-standard 2>/dev/null)" ]; then
+    echo "[specify] No changes to commit after $EVENT_NAME" >&2
+    exit 0
+fi
+
+# Derive a human-readable command name from the event
+# e.g., after_specify -> specify, before_plan -> plan
+_command_name=$(echo "$EVENT_NAME" | sed 's/^after_//' | sed 's/^before_//')
+_phase=$(echo "$EVENT_NAME" | grep -q '^before_' && echo 'before' || echo 'after')
+
+# Use custom message if configured, otherwise default
+if [ -z "$_commit_msg" ]; then
+    _commit_msg="[Spec Kit] Auto-commit ${_phase} ${_command_name}"
+fi
+
+# Stage and commit
+_git_out=$(git add . 2>&1) || { echo "[specify] Error: git add failed: $_git_out" >&2; exit 1; }
+_git_out=$(git commit -q -m "$_commit_msg" 2>&1) || { echo "[specify] Error: git commit failed: $_git_out" >&2; exit 1; }
+
+echo "✓ Changes committed ${_phase} ${_command_name}" >&2
--- a/extensions/git/scripts/bash/create-new-feature.sh
+++ b/extensions/git/scripts/bash/create-new-feature.sh
@@ -0,0 +1,451 @@
+#!/usr/bin/env bash
+# Git extension: create-new-feature.sh
+# Adapted from core scripts/bash/create-new-feature.sh for extension layout.
+# Sources common.sh from the project's installed scripts, falling back to
+# git-common.sh for minimal git helpers.
+
+set -e
+
+JSON_MODE=false
+DRY_RUN=false
+ALLOW_EXISTING=false
+SHORT_NAME=""
+BRANCH_NUMBER=""
+USE_TIMESTAMP=false
+ARGS=()
+i=1
+while [ $i -le $# ]; do
+    arg="${!i}"
+    case "$arg" in
+        --json)
+            JSON_MODE=true
+            ;;
+        --dry-run)
+            DRY_RUN=true
+            ;;
+        --allow-existing-branch)
+            ALLOW_EXISTING=true
+            ;;
+        --short-name)
+            if [ $((i + 1)) -gt $# ]; then
+                echo 'Error: --short-name requires a value' >&2
+                exit 1
+            fi
+            i=$((i + 1))
+            next_arg="${!i}"
+            if [[ "$next_arg" == --* ]]; then
+                echo 'Error: --short-name requires a value' >&2
+                exit 1
+            fi
+            SHORT_NAME="$next_arg"
+            ;;
+        --number)
+            if [ $((i + 1)) -gt $# ]; then
+                echo 'Error: --number requires a value' >&2
+                exit 1
+            fi
+            i=$((i + 1))
+            next_arg="${!i}"
+            if [[ "$next_arg" == --* ]]; then
+                echo 'Error: --number requires a value' >&2
+                exit 1
+            fi
+            BRANCH_NUMBER="$next_arg"
+            if [[ ! "$BRANCH_NUMBER" =~ ^[0-9]+$ ]]; then
+                echo 'Error: --number must be a non-negative integer' >&2
+                exit 1
+            fi
+            ;;
+        --timestamp)
+            USE_TIMESTAMP=true
+            ;;
+        --help|-h)
+            echo "Usage: $0 [--json] [--dry-run] [--allow-existing-branch] [--short-name <name>] [--number N] [--timestamp] <feature_description>"
+            echo ""
+            echo "Options:"
+            echo "  --json              Output in JSON format"
+            echo "  --dry-run           Compute branch name and paths without creating branches, directories, or files"
+            echo "  --allow-existing-branch  Switch to branch if it already exists instead of failing"
+            echo "  --short-name <name> Provide a custom short name (2-4 words) for the branch"
+            echo "  --number N          Specify branch number manually (overrides auto-detection)"
+            echo "  --timestamp         Use timestamp prefix (YYYYMMDD-HHMMSS) instead of sequential numbering"
+            echo "  --help, -h          Show this help message"
+            echo ""
+            echo "Examples:"
+            echo "  $0 'Add user authentication system' --short-name 'user-auth'"
+            echo "  $0 'Implement OAuth2 integration for API' --number 5"
+            echo "  $0 --timestamp --short-name 'user-auth' 'Add user authentication'"
+            exit 0
+            ;;
+        *)
+            ARGS+=("$arg")
+            ;;
+    esac
+    i=$((i + 1))
+done
+
+FEATURE_DESCRIPTION="${ARGS[*]}"
+if [ -z "$FEATURE_DESCRIPTION" ]; then
+    echo "Usage: $0 [--json] [--dry-run] [--allow-existing-branch] [--short-name <name>] [--number N] [--timestamp] <feature_description>" >&2
+    exit 1
+fi
+
+# Trim whitespace and validate description is not empty
+FEATURE_DESCRIPTION=$(echo "$FEATURE_DESCRIPTION" | xargs)
+if [ -z "$FEATURE_DESCRIPTION" ]; then
+    echo "Error: Feature description cannot be empty or contain only whitespace" >&2
+    exit 1
+fi
+
+# Function to get highest number from specs directory
+get_highest_from_specs() {
+    local specs_dir="$1"
+    local highest=0
+
+    if [ -d "$specs_dir" ]; then
+        for dir in "$specs_dir"/*; do
+            [ -d "$dir" ] || continue
+            dirname=$(basename "$dir")
+            # Match sequential prefixes (>=3 digits), but skip timestamp dirs.
+            if echo "$dirname" | grep -Eq '^[0-9]{3,}-' && ! echo "$dirname" | grep -Eq '^[0-9]{8}-[0-9]{6}-'; then
+                number=$(echo "$dirname" | grep -Eo '^[0-9]+')
+                number=$((10#$number))
+                if [ "$number" -gt "$highest" ]; then
+                    highest=$number
+                fi
+            fi
+        done
+    fi
+
+    echo "$highest"
+}
+
+# Function to get highest number from git branches
+get_highest_from_branches() {
+    git branch -a 2>/dev/null | sed 's/^[* ]*//; s|^remotes/[^/]*/||' | _extract_highest_number
+}
+
+# Extract the highest sequential feature number from a list of ref names (one per line).
+_extract_highest_number() {
+    local highest=0
+    while IFS= read -r name; do
+        [ -z "$name" ] && continue
+        if echo "$name" | grep -Eq '^[0-9]{3,}-' && ! echo "$name" | grep -Eq '^[0-9]{8}-[0-9]{6}-'; then
+            number=$(echo "$name" | grep -Eo '^[0-9]+' || echo "0")
+            number=$((10#$number))
+            if [ "$number" -gt "$highest" ]; then
+                highest=$number
+            fi
+        fi
+    done
+    echo "$highest"
+}
+
+# Function to get highest number from remote branches without fetching (side-effect-free)
+get_highest_from_remote_refs() {
+    local highest=0
+
+    for remote in $(git remote 2>/dev/null); do
+        local remote_highest
+        remote_highest=$(GIT_TERMINAL_PROMPT=0 git ls-remote --heads "$remote" 2>/dev/null | sed 's|.*refs/heads/||' | _extract_highest_number)
+        if [ "$remote_highest" -gt "$highest" ]; then
+            highest=$remote_highest
+        fi
+    done
+
+    echo "$highest"
+}
+
+# Function to check existing branches and return next available number.
+check_existing_branches() {
+    local specs_dir="$1"
+    local skip_fetch="${2:-false}"
+
+    if [ "$skip_fetch" = true ]; then
+        local highest_remote=$(get_highest_from_remote_refs)
+        local highest_branch=$(get_highest_from_branches)
+        if [ "$highest_remote" -gt "$highest_branch" ]; then
+            highest_branch=$highest_remote
+        fi
+    else
+        git fetch --all --prune >/dev/null 2>&1 || true
+        local highest_branch=$(get_highest_from_branches)
+    fi
+
+    local highest_spec=$(get_highest_from_specs "$specs_dir")
+
+    local max_num=$highest_branch
+    if [ "$highest_spec" -gt "$max_num" ]; then
+        max_num=$highest_spec
+    fi
+
+    echo $((max_num + 1))
+}
+
+# Function to clean and format a branch name
+clean_branch_name() {
+    local name="$1"
+    echo "$name" | tr '[:upper:]' '[:lower:]' | sed 's/[^a-z0-9]/-/g' | sed 's/-\+/-/g' | sed 's/^-//' | sed 's/-$//'
+}
+
+# ---------------------------------------------------------------------------
+# Source common.sh for resolve_template, json_escape, get_repo_root, has_git.
+#
+# Search locations in priority order:
+#  1. .specify/scripts/bash/common.sh under the project root (installed project)
+#  2. scripts/bash/common.sh under the project root (source checkout fallback)
+#  3. git-common.sh next to this script (minimal fallback — lacks resolve_template)
+# ---------------------------------------------------------------------------
+SCRIPT_DIR="$(CDPATH="" cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+# Find project root by walking up from the script location
+_find_project_root() {
+    local dir="$1"
+    while [ "$dir" != "/" ]; do
+        if [ -d "$dir/.specify" ] || [ -d "$dir/.git" ]; then
+            echo "$dir"
+            return 0
+        fi
+        dir="$(dirname "$dir")"
+    done
+    return 1
+}
+
+_common_loaded=false
+_PROJECT_ROOT=$(_find_project_root "$SCRIPT_DIR") || true
+
+if [ -n "$_PROJECT_ROOT" ] && [ -f "$_PROJECT_ROOT/.specify/scripts/bash/common.sh" ]; then
+    source "$_PROJECT_ROOT/.specify/scripts/bash/common.sh"
+    _common_loaded=true
+elif [ -n "$_PROJECT_ROOT" ] && [ -f "$_PROJECT_ROOT/scripts/bash/common.sh" ]; then
+    source "$_PROJECT_ROOT/scripts/bash/common.sh"
+    _common_loaded=true
+elif [ -f "$SCRIPT_DIR/git-common.sh" ]; then
+    source "$SCRIPT_DIR/git-common.sh"
+    _common_loaded=true
+fi
+
+if [ "$_common_loaded" != "true" ]; then
+    echo "Error: Could not locate common.sh or git-common.sh. Please ensure the Specify core scripts are installed." >&2
+    exit 1
+fi
+
+# Resolve repository root
+if type get_repo_root >/dev/null 2>&1; then
+    REPO_ROOT=$(get_repo_root)
+elif git rev-parse --show-toplevel >/dev/null 2>&1; then
+    REPO_ROOT=$(git rev-parse --show-toplevel)
+elif [ -n "$_PROJECT_ROOT" ]; then
+    REPO_ROOT="$_PROJECT_ROOT"
+else
+    echo "Error: Could not determine repository root." >&2
+    exit 1
+fi
+
+# Check if git is available at this repo root
+if type has_git >/dev/null 2>&1; then
+    if has_git "$REPO_ROOT"; then
+        HAS_GIT=true
+    else
+        HAS_GIT=false
+    fi
+elif git -C "$REPO_ROOT" rev-parse --is-inside-work-tree >/dev/null 2>&1; then
+    HAS_GIT=true
+else
+    HAS_GIT=false
+fi
+
+cd "$REPO_ROOT"
+
+SPECS_DIR="$REPO_ROOT/specs"
+if [ "$DRY_RUN" != true ]; then
+    mkdir -p "$SPECS_DIR"
+fi
+
+# Function to generate branch name with stop word filtering
+generate_branch_name() {
+    local description="$1"
+
+    local stop_words="^(i|a|an|the|to|for|of|in|on|at|by|with|from|is|are|was|were|be|been|being|have|has|had|do|does|did|will|would|should|could|can|may|might|must|shall|this|that|these|those|my|your|our|their|want|need|add|get|set)$"
+
+    local clean_name=$(echo "$description" | tr '[:upper:]' '[:lower:]' | sed 's/[^a-z0-9]/ /g')
+
+    local meaningful_words=()
+    for word in $clean_name; do
+        [ -z "$word" ] && continue
+        if ! echo "$word" | grep -qiE "$stop_words"; then
+            if [ ${#word} -ge 3 ]; then
+                meaningful_words+=("$word")
+            elif echo "$description" | grep -qw -- "${word^^}"; then
+                meaningful_words+=("$word")
+            fi
+        fi
+    done
+
+    if [ ${#meaningful_words[@]} -gt 0 ]; then
+        local max_words=3
+        if [ ${#meaningful_words[@]} -eq 4 ]; then max_words=4; fi
+
+        local result=""
+        local count=0
+        for word in "${meaningful_words[@]}"; do
+            if [ $count -ge $max_words ]; then break; fi
+            if [ -n "$result" ]; then result="$result-"; fi
+            result="$result$word"
+            count=$((count + 1))
+        done
+        echo "$result"
+    else
+        local cleaned=$(clean_branch_name "$description")
+        echo "$cleaned" | tr '-' '\n' | grep -v '^$' | head -3 | tr '\n' '-' | sed 's/-$//'
+    fi
+}
+
+# Generate branch name
+if [ -n "$SHORT_NAME" ]; then
+    BRANCH_SUFFIX=$(clean_branch_name "$SHORT_NAME")
+else
+    BRANCH_SUFFIX=$(generate_branch_name "$FEATURE_DESCRIPTION")
+fi
+
+# Warn if --number and --timestamp are both specified
+if [ "$USE_TIMESTAMP" = true ] && [ -n "$BRANCH_NUMBER" ]; then
+    >&2 echo "[specify] Warning: --number is ignored when --timestamp is used"
+    BRANCH_NUMBER=""
+fi
+
+# Determine branch prefix
+if [ "$USE_TIMESTAMP" = true ]; then
+    FEATURE_NUM=$(date +%Y%m%d-%H%M%S)
+    BRANCH_NAME="${FEATURE_NUM}-${BRANCH_SUFFIX}"
+else
+    if [ -z "$BRANCH_NUMBER" ]; then
+        if [ "$DRY_RUN" = true ] && [ "$HAS_GIT" = true ]; then
+            BRANCH_NUMBER=$(check_existing_branches "$SPECS_DIR" true)
+        elif [ "$DRY_RUN" = true ]; then
+            HIGHEST=$(get_highest_from_specs "$SPECS_DIR")
+            BRANCH_NUMBER=$((HIGHEST + 1))
+        elif [ "$HAS_GIT" = true ]; then
+            BRANCH_NUMBER=$(check_existing_branches "$SPECS_DIR")
+        else
+            HIGHEST=$(get_highest_from_specs "$SPECS_DIR")
+            BRANCH_NUMBER=$((HIGHEST + 1))
+        fi
+    fi
+
+    FEATURE_NUM=$(printf "%03d" "$((10#$BRANCH_NUMBER))")
+    BRANCH_NAME="${FEATURE_NUM}-${BRANCH_SUFFIX}"
+fi
+
+# GitHub enforces a 244-byte limit on branch names
+MAX_BRANCH_LENGTH=244
+if [ ${#BRANCH_NAME} -gt $MAX_BRANCH_LENGTH ]; then
+    PREFIX_LENGTH=$(( ${#FEATURE_NUM} + 1 ))
+    MAX_SUFFIX_LENGTH=$((MAX_BRANCH_LENGTH - PREFIX_LENGTH))
+
+    TRUNCATED_SUFFIX=$(echo "$BRANCH_SUFFIX" | cut -c1-$MAX_SUFFIX_LENGTH)
+    TRUNCATED_SUFFIX=$(echo "$TRUNCATED_SUFFIX" | sed 's/-$//')
+
+    ORIGINAL_BRANCH_NAME="$BRANCH_NAME"
+    BRANCH_NAME="${FEATURE_NUM}-${TRUNCATED_SUFFIX}"
+
+    >&2 echo "[specify] Warning: Branch name exceeded GitHub's 244-byte limit"
+    >&2 echo "[specify] Original: $ORIGINAL_BRANCH_NAME (${#ORIGINAL_BRANCH_NAME} bytes)"
+    >&2 echo "[specify] Truncated to: $BRANCH_NAME (${#BRANCH_NAME} bytes)"
+fi
+
+FEATURE_DIR="$SPECS_DIR/$BRANCH_NAME"
+SPEC_FILE="$FEATURE_DIR/spec.md"
+
+if [ "$DRY_RUN" != true ]; then
+    if [ "$HAS_GIT" = true ]; then
+        branch_create_error=""
+        if ! branch_create_error=$(git checkout -q -b "$BRANCH_NAME" 2>&1); then
+            current_branch="$(git rev-parse --abbrev-ref HEAD 2>/dev/null || true)"
+            if git branch --list "$BRANCH_NAME" | grep -q .; then
+                if [ "$ALLOW_EXISTING" = true ]; then
+                    if [ "$current_branch" = "$BRANCH_NAME" ]; then
+                        :
+                    elif ! git checkout "$BRANCH_NAME" 2>/dev/null; then
+                        >&2 echo "Error: Failed to switch to existing branch '$BRANCH_NAME'. Please resolve any local changes or conflicts and try again."
+                        exit 1
+                    fi
+                elif [ "$USE_TIMESTAMP" = true ]; then
+                    >&2 echo "Error: Branch '$BRANCH_NAME' already exists. Rerun to get a new timestamp or use a different --short-name."
+                    exit 1
+                else
+                    >&2 echo "Error: Branch '$BRANCH_NAME' already exists. Please use a different feature name or specify a different number with --number."
+                    exit 1
+                fi
+            else
+                >&2 echo "Error: Failed to create git branch '$BRANCH_NAME'."
+                if [ -n "$branch_create_error" ]; then
+                    >&2 printf '%s\n' "$branch_create_error"
+                else
+                    >&2 echo "Please check your git configuration and try again."
+                fi
+                exit 1
+            fi
+        fi
+    else
+        >&2 echo "[specify] Warning: Git repository not detected; skipped branch creation for $BRANCH_NAME"
+    fi
+
+    mkdir -p "$FEATURE_DIR"
+
+    if [ ! -f "$SPEC_FILE" ]; then
+        if type resolve_template >/dev/null 2>&1; then
+            TEMPLATE=$(resolve_template "spec-template" "$REPO_ROOT") || true
+        else
+            TEMPLATE=""
+        fi
+        if [ -n "$TEMPLATE" ] && [ -f "$TEMPLATE" ]; then
+            cp "$TEMPLATE" "$SPEC_FILE"
+        else
+            echo "Warning: Spec template not found; created empty spec file" >&2
+            touch "$SPEC_FILE"
+        fi
+    fi
+
+    printf '# To persist: export SPECIFY_FEATURE=%q\n' "$BRANCH_NAME" >&2
+fi
+
+if $JSON_MODE; then
+    if command -v jq >/dev/null 2>&1; then
+        if [ "$DRY_RUN" = true ]; then
+            jq -cn \
+                --arg branch_name "$BRANCH_NAME" \
+                --arg spec_file "$SPEC_FILE" \
+                --arg feature_num "$FEATURE_NUM" \
+                '{BRANCH_NAME:$branch_name,SPEC_FILE:$spec_file,FEATURE_NUM:$feature_num,DRY_RUN:true}'
+        else
+            jq -cn \
+                --arg branch_name "$BRANCH_NAME" \
+                --arg spec_file "$SPEC_FILE" \
+                --arg feature_num "$FEATURE_NUM" \
+                '{BRANCH_NAME:$branch_name,SPEC_FILE:$spec_file,FEATURE_NUM:$feature_num}'
+        fi
+    else
+        if type json_escape >/dev/null 2>&1; then
+            _je_branch=$(json_escape "$BRANCH_NAME")
+            _je_spec=$(json_escape "$SPEC_FILE")
+            _je_num=$(json_escape "$FEATURE_NUM")
+        else
+            _je_branch="$BRANCH_NAME"
+            _je_spec="$SPEC_FILE"
+            _je_num="$FEATURE_NUM"
+        fi
+        if [ "$DRY_RUN" = true ]; then
+            printf '{"BRANCH_NAME":"%s","SPEC_FILE":"%s","FEATURE_NUM":"%s","DRY_RUN":true}\n' "$_je_branch" "$_je_spec" "$_je_num"
+        else
+            printf '{"BRANCH_NAME":"%s","SPEC_FILE":"%s","FEATURE_NUM":"%s"}\n' "$_je_branch" "$_je_spec" "$_je_num"
+        fi
+    fi
+else
+    echo "BRANCH_NAME: $BRANCH_NAME"
+    echo "SPEC_FILE: $SPEC_FILE"
+    echo "FEATURE_NUM: $FEATURE_NUM"
+    if [ "$DRY_RUN" != true ]; then
+        printf '# To persist in your shell: export SPECIFY_FEATURE=%q\n' "$BRANCH_NAME"
+    fi
+fi
--- a/extensions/git/scripts/bash/git-common.sh
+++ b/extensions/git/scripts/bash/git-common.sh
@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+# Git-specific common functions for the git extension.
+# Extracted from scripts/bash/common.sh — contains only git-specific
+# branch validation and detection logic.
+
+# Check if we have git available at the repo root
+has_git() {
+    local repo_root="${1:-$(pwd)}"
+    { [ -d "$repo_root/.git" ] || [ -f "$repo_root/.git" ]; } && \
+        command -v git >/dev/null 2>&1 && \
+        git -C "$repo_root" rev-parse --is-inside-work-tree >/dev/null 2>&1
+}
+
+# Validate that a branch name matches the expected feature branch pattern.
+# Accepts sequential (###-* with >=3 digits) or timestamp (YYYYMMDD-HHMMSS-*) formats.
+check_feature_branch() {
+    local branch="$1"
+    local has_git_repo="$2"
+
+    # For non-git repos, we can't enforce branch naming but still provide output
+    if [[ "$has_git_repo" != "true" ]]; then
+        echo "[specify] Warning: Git repository not detected; skipped branch validation" >&2
+        return 0
+    fi
+
+    # Reject malformed timestamps (7-digit date, 8-digit date without trailing slug, or 7-digit with slug)
+    if [[ "$branch" =~ ^[0-9]{7}-[0-9]{6} ]] || [[ "$branch" =~ ^[0-9]{8}-[0-9]{6}$ ]]; then
+        echo "ERROR: Not on a feature branch. Current branch: $branch" >&2
+        echo "Feature branches should be named like: 001-feature-name or 20260319-143022-feature-name" >&2
+        return 1
+    fi
+
+    # Accept sequential (>=3 digits followed by hyphen) or timestamp (YYYYMMDD-HHMMSS-*)
+    if [[ "$branch" =~ ^[0-9]{3,}- ]] || [[ "$branch" =~ ^[0-9]{8}-[0-9]{6}- ]]; then
+        return 0
+    fi
+
+    echo "ERROR: Not on a feature branch. Current branch: $branch" >&2
+    echo "Feature branches should be named like: 001-feature-name or 20260319-143022-feature-name" >&2
+    return 1
+}
--- a/extensions/git/scripts/bash/initialize-repo.sh
+++ b/extensions/git/scripts/bash/initialize-repo.sh
@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+# Git extension: initialize-repo.sh
+# Initialize a Git repository with an initial commit.
+# Customizable — replace this script to add .gitignore templates,
+# default branch config, git-flow, LFS, signing, etc.
+
+set -e
+
+SCRIPT_DIR="$(CDPATH="" cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+# Find project root
+_find_project_root() {
+    local dir="$1"
+    while [ "$dir" != "/" ]; do
+        if [ -d "$dir/.specify" ] || [ -d "$dir/.git" ]; then
+            echo "$dir"
+            return 0
+        fi
+        dir="$(dirname "$dir")"
+    done
+    return 1
+}
+
+REPO_ROOT=$(_find_project_root "$SCRIPT_DIR") || REPO_ROOT="$(pwd)"
+cd "$REPO_ROOT"
+
+# Read commit message from extension config, fall back to default
+COMMIT_MSG="[Spec Kit] Initial commit"
+_config_file="$REPO_ROOT/.specify/extensions/git/git-config.yml"
+if [ -f "$_config_file" ]; then
+    _msg=$(grep '^init_commit_message:' "$_config_file" 2>/dev/null | sed 's/^init_commit_message:[[:space:]]*//' | sed 's/^["'\'']//' | sed 's/["'\'']*$//')
+    if [ -n "$_msg" ]; then
+        COMMIT_MSG="$_msg"
+    fi
+fi
+
+# Check if git is available
+if ! command -v git >/dev/null 2>&1; then
+    echo "[specify] Warning: Git not found; skipped repository initialization" >&2
+    exit 0
+fi
+
+# Check if already a git repo
+if git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
+    echo "[specify] Git repository already initialized; skipping" >&2
+    exit 0
+fi
+
+# Initialize
+_git_out=$(git init -q 2>&1) || { echo "[specify] Error: git init failed: $_git_out" >&2; exit 1; }
+_git_out=$(git add . 2>&1) || { echo "[specify] Error: git add failed: $_git_out" >&2; exit 1; }
+_git_out=$(git commit --allow-empty -q -m "$COMMIT_MSG" 2>&1) || { echo "[specify] Error: git commit failed: $_git_out" >&2; exit 1; }
+
+echo "✓ Git repository initialized" >&2
--- a/extensions/git/scripts/powershell/auto-commit.ps1
+++ b/extensions/git/scripts/powershell/auto-commit.ps1
@@ -0,0 +1,149 @@
+#!/usr/bin/env pwsh
+# Git extension: auto-commit.ps1
+# Automatically commit changes after a Spec Kit command completes.
+# Checks per-command config keys in git-config.yml before committing.
+#
+# Usage: auto-commit.ps1 <event_name>
+#   e.g.: auto-commit.ps1 after_specify
+param(
+    [Parameter(Position = 0, Mandatory = $true)]
+    [string]$EventName
+)
+$ErrorActionPreference = 'Stop'
+
+function Find-ProjectRoot {
+    param([string]$StartDir)
+    $current = Resolve-Path $StartDir
+    while ($true) {
+        foreach ($marker in @('.specify', '.git')) {
+            if (Test-Path (Join-Path $current $marker)) {
+                return $current
+            }
+        }
+        $parent = Split-Path $current -Parent
+        if ($parent -eq $current) { return $null }
+        $current = $parent
+    }
+}
+
+$repoRoot = Find-ProjectRoot -StartDir $PSScriptRoot
+if (-not $repoRoot) { $repoRoot = Get-Location }
+Set-Location $repoRoot
+
+# Check if git is available
+if (-not (Get-Command git -ErrorAction SilentlyContinue)) {
+    Write-Warning "[specify] Warning: Git not found; skipped auto-commit"
+    exit 0
+}
+
+try {
+    git rev-parse --is-inside-work-tree 2>$null | Out-Null
+    if ($LASTEXITCODE -ne 0) { throw "not a repo" }
+} catch {
+    Write-Warning "[specify] Warning: Not a Git repository; skipped auto-commit"
+    exit 0
+}
+
+# Read per-command config from git-config.yml
+$configFile = Join-Path $repoRoot ".specify/extensions/git/git-config.yml"
+$enabled = $false
+$commitMsg = ""
+
+if (Test-Path $configFile) {
+    # Parse YAML to find auto_commit section
+    $inAutoCommit = $false
+    $inEvent = $false
+    $defaultEnabled = $false
+
+    foreach ($line in Get-Content $configFile) {
+        # Detect auto_commit: section
+        if ($line -match '^auto_commit:') {
+            $inAutoCommit = $true
+            $inEvent = $false
+            continue
+        }
+
+        # Exit auto_commit section on next top-level key
+        if ($inAutoCommit -and $line -match '^[a-z]') {
+            break
+        }
+
+        if ($inAutoCommit) {
+            # Check default key
+            if ($line -match '^\s+default:\s*(.+)$') {
+                $val = $matches[1].Trim().ToLower()
+                if ($val -eq 'true') { $defaultEnabled = $true }
+            }
+
+            # Detect our event subsection
+            if ($line -match "^\s+${EventName}:") {
+                $inEvent = $true
+                continue
+            }
+
+            # Inside our event subsection
+            if ($inEvent) {
+                # Exit on next sibling key (2-space indent, not 4+)
+                if ($line -match '^\s{2}[a-z]' -and $line -notmatch '^\s{4}') {
+                    $inEvent = $false
+                    continue
+                }
+                if ($line -match '\s+enabled:\s*(.+)$') {
+                    $val = $matches[1].Trim().ToLower()
+                    if ($val -eq 'true') { $enabled = $true }
+                    if ($val -eq 'false') { $enabled = $false }
+                }
+                if ($line -match '\s+message:\s*(.+)$') {
+                    $commitMsg = $matches[1].Trim() -replace '^["'']' -replace '["'']$'
+                }
+            }
+        }
+    }
+
+    # If event-specific key not found, use default
+    if (-not $enabled -and $defaultEnabled) {
+        $hasEventKey = Select-String -Path $configFile -Pattern "^\s*${EventName}:" -Quiet
+        if (-not $hasEventKey) {
+            $enabled = $true
+        }
+    }
+} else {
+    # No config file — auto-commit disabled by default
+    exit 0
+}
+
+if (-not $enabled) {
+    exit 0
+}
+
+# Check if there are changes to commit
+$diffHead = git diff --quiet HEAD 2>$null; $d1 = $LASTEXITCODE
+$diffCached = git diff --cached --quiet 2>$null; $d2 = $LASTEXITCODE
+$untracked = git ls-files --others --exclude-standard 2>$null
+
+if ($d1 -eq 0 -and $d2 -eq 0 -and -not $untracked) {
+    Write-Host "[specify] No changes to commit after $EventName" -ForegroundColor DarkGray
+    exit 0
+}
+
+# Derive a human-readable command name from the event
+$commandName = $EventName -replace '^after_', '' -replace '^before_', ''
+$phase = if ($EventName -match '^before_') { 'before' } else { 'after' }
+
+# Use custom message if configured, otherwise default
+if (-not $commitMsg) {
+    $commitMsg = "[Spec Kit] Auto-commit $phase $commandName"
+}
+
+# Stage and commit
+try {
+    $out = git add . 2>&1 | Out-String
+    if ($LASTEXITCODE -ne 0) { throw "git add failed: $out" }
+    $out = git commit -q -m $commitMsg 2>&1 | Out-String
+    if ($LASTEXITCODE -ne 0) { throw "git commit failed: $out" }
+} catch {
+    Write-Warning "[specify] Error: $_"
+    exit 1
+}
+
+Write-Host "✓ Changes committed $phase $commandName"
--- a/extensions/git/scripts/powershell/create-new-feature.ps1
+++ b/extensions/git/scripts/powershell/create-new-feature.ps1
@@ -0,0 +1,397 @@
+#!/usr/bin/env pwsh
+# Git extension: create-new-feature.ps1
+# Adapted from core scripts/powershell/create-new-feature.ps1 for extension layout.
+# Sources common.ps1 from the project's installed scripts, falling back to
+# git-common.ps1 for minimal git helpers.
+[CmdletBinding()]
+param(
+    [switch]$Json,
+    [switch]$AllowExistingBranch,
+    [switch]$DryRun,
+    [string]$ShortName,
+    [Parameter()]
+    [long]$Number = 0,
+    [switch]$Timestamp,
+    [switch]$Help,
+    [Parameter(Position = 0, ValueFromRemainingArguments = $true)]
+    [string[]]$FeatureDescription
+)
+$ErrorActionPreference = 'Stop'
+
+if ($Help) {
+    Write-Host "Usage: ./create-new-feature.ps1 [-Json] [-DryRun] [-AllowExistingBranch] [-ShortName <name>] [-Number N] [-Timestamp] <feature description>"
+    Write-Host ""
+    Write-Host "Options:"
+    Write-Host "  -Json               Output in JSON format"
+    Write-Host "  -DryRun             Compute branch name and paths without creating branches, directories, or files"
+    Write-Host "  -AllowExistingBranch  Switch to branch if it already exists instead of failing"
+    Write-Host "  -ShortName <name>   Provide a custom short name (2-4 words) for the branch"
+    Write-Host "  -Number N           Specify branch number manually (overrides auto-detection)"
+    Write-Host "  -Timestamp          Use timestamp prefix (YYYYMMDD-HHMMSS) instead of sequential numbering"
+    Write-Host "  -Help               Show this help message"
+    exit 0
+}
+
+if (-not $FeatureDescription -or $FeatureDescription.Count -eq 0) {
+    Write-Error "Usage: ./create-new-feature.ps1 [-Json] [-DryRun] [-AllowExistingBranch] [-ShortName <name>] [-Number N] [-Timestamp] <feature description>"
+    exit 1
+}
+
+$featureDesc = ($FeatureDescription -join ' ').Trim()
+
+if ([string]::IsNullOrWhiteSpace($featureDesc)) {
+    Write-Error "Error: Feature description cannot be empty or contain only whitespace"
+    exit 1
+}
+
+function Get-HighestNumberFromSpecs {
+    param([string]$SpecsDir)
+
+    [long]$highest = 0
+    if (Test-Path $SpecsDir) {
+        Get-ChildItem -Path $SpecsDir -Directory | ForEach-Object {
+            if ($_.Name -match '^(\d{3,})-' -and $_.Name -notmatch '^\d{8}-\d{6}-') {
+                [long]$num = 0
+                if ([long]::TryParse($matches[1], [ref]$num) -and $num -gt $highest) {
+                    $highest = $num
+                }
+            }
+        }
+    }
+    return $highest
+}
+
+function Get-HighestNumberFromNames {
+    param([string[]]$Names)
+
+    [long]$highest = 0
+    foreach ($name in $Names) {
+        if ($name -match '^(\d{3,})-' -and $name -notmatch '^\d{8}-\d{6}-') {
+            [long]$num = 0
+            if ([long]::TryParse($matches[1], [ref]$num) -and $num -gt $highest) {
+                $highest = $num
+            }
+        }
+    }
+    return $highest
+}
+
+function Get-HighestNumberFromBranches {
+    param()
+
+    try {
+        $branches = git branch -a 2>$null
+        if ($LASTEXITCODE -eq 0 -and $branches) {
+            $cleanNames = $branches | ForEach-Object {
+                $_.Trim() -replace '^\*?\s+', '' -replace '^remotes/[^/]+/', ''
+            }
+            return Get-HighestNumberFromNames -Names $cleanNames
+        }
+    } catch {
+        Write-Verbose "Could not check Git branches: $_"
+    }
+    return 0
+}
+
+function Get-HighestNumberFromRemoteRefs {
+    [long]$highest = 0
+    try {
+        $remotes = git remote 2>$null
+        if ($remotes) {
+            foreach ($remote in $remotes) {
+                $env:GIT_TERMINAL_PROMPT = '0'
+                $refs = git ls-remote --heads $remote 2>$null
+                $env:GIT_TERMINAL_PROMPT = $null
+                if ($LASTEXITCODE -eq 0 -and $refs) {
+                    $refNames = $refs | ForEach-Object {
+                        if ($_ -match 'refs/heads/(.+)$') { $matches[1] }
+                    } | Where-Object { $_ }
+                    $remoteHighest = Get-HighestNumberFromNames -Names $refNames
+                    if ($remoteHighest -gt $highest) { $highest = $remoteHighest }
+                }
+            }
+        }
+    } catch {
+        Write-Verbose "Could not query remote refs: $_"
+    }
+    return $highest
+}
+
+function Get-NextBranchNumber {
+    param(
+        [string]$SpecsDir,
+        [switch]$SkipFetch
+    )
+
+    if ($SkipFetch) {
+        $highestBranch = Get-HighestNumberFromBranches
+        $highestRemote = Get-HighestNumberFromRemoteRefs
+        $highestBranch = [Math]::Max($highestBranch, $highestRemote)
+    } else {
+        try {
+            git fetch --all --prune 2>$null | Out-Null
+        } catch { }
+        $highestBranch = Get-HighestNumberFromBranches
+    }
+
+    $highestSpec = Get-HighestNumberFromSpecs -SpecsDir $SpecsDir
+    $maxNum = [Math]::Max($highestBranch, $highestSpec)
+    return $maxNum + 1
+}
+
+function ConvertTo-CleanBranchName {
+    param([string]$Name)
+    return $Name.ToLower() -replace '[^a-z0-9]', '-' -replace '-{2,}', '-' -replace '^-', '' -replace '-$', ''
+}
+
+# ---------------------------------------------------------------------------
+# Source common.ps1 from the project's installed scripts.
+# Search locations in priority order:
+#  1. .specify/scripts/powershell/common.ps1 under the project root
+#  2. scripts/powershell/common.ps1 under the project root (source checkout)
+#  3. git-common.ps1 next to this script (minimal fallback)
+# ---------------------------------------------------------------------------
+function Find-ProjectRoot {
+    param([string]$StartDir)
+    $current = Resolve-Path $StartDir
+    while ($true) {
+        foreach ($marker in @('.specify', '.git')) {
+            if (Test-Path (Join-Path $current $marker)) {
+                return $current
+            }
+        }
+        $parent = Split-Path $current -Parent
+        if ($parent -eq $current) { return $null }
+        $current = $parent
+    }
+}
+
+$projectRoot = Find-ProjectRoot -StartDir $PSScriptRoot
+$commonLoaded = $false
+
+if ($projectRoot) {
+    $candidates = @(
+        (Join-Path $projectRoot ".specify/scripts/powershell/common.ps1"),
+        (Join-Path $projectRoot "scripts/powershell/common.ps1")
+    )
+    foreach ($candidate in $candidates) {
+        if (Test-Path $candidate) {
+            . $candidate
+            $commonLoaded = $true
+            break
+        }
+    }
+}
+
+if (-not $commonLoaded -and (Test-Path "$PSScriptRoot/git-common.ps1")) {
+    . "$PSScriptRoot/git-common.ps1"
+    $commonLoaded = $true
+}
+
+if (-not $commonLoaded) {
+    throw "Unable to locate common script file. Please ensure the Specify core scripts are installed."
+}
+
+# Resolve repository root
+if (Get-Command Get-RepoRoot -ErrorAction SilentlyContinue) {
+    $repoRoot = Get-RepoRoot
+} elseif ($projectRoot) {
+    $repoRoot = $projectRoot
+} else {
+    throw "Could not determine repository root."
+}
+
+# Check if git is available
+if (Get-Command Test-HasGit -ErrorAction SilentlyContinue) {
+    $hasGit = Test-HasGit -RepoRoot $repoRoot
+} else {
+    try {
+        git -C $repoRoot rev-parse --is-inside-work-tree 2>$null | Out-Null
+        $hasGit = ($LASTEXITCODE -eq 0)
+    } catch {
+        $hasGit = $false
+    }
+}
+
+Set-Location $repoRoot
+
+$specsDir = Join-Path $repoRoot 'specs'
+if (-not $DryRun) {
+    New-Item -ItemType Directory -Path $specsDir -Force | Out-Null
+}
+
+function Get-BranchName {
+    param([string]$Description)
+
+    $stopWords = @(
+        'i', 'a', 'an', 'the', 'to', 'for', 'of', 'in', 'on', 'at', 'by', 'with', 'from',
+        'is', 'are', 'was', 'were', 'be', 'been', 'being', 'have', 'has', 'had',
+        'do', 'does', 'did', 'will', 'would', 'should', 'could', 'can', 'may', 'might', 'must', 'shall',
+        'this', 'that', 'these', 'those', 'my', 'your', 'our', 'their',
+        'want', 'need', 'add', 'get', 'set'
+    )
+
+    $cleanName = $Description.ToLower() -replace '[^a-z0-9\s]', ' '
+    $words = $cleanName -split '\s+' | Where-Object { $_ }
+
+    $meaningfulWords = @()
+    foreach ($word in $words) {
+        if ($stopWords -contains $word) { continue }
+        if ($word.Length -ge 3) {
+            $meaningfulWords += $word
+        } elseif ($Description -match "\b$($word.ToUpper())\b") {
+            $meaningfulWords += $word
+        }
+    }
+
+    if ($meaningfulWords.Count -gt 0) {
+        $maxWords = if ($meaningfulWords.Count -eq 4) { 4 } else { 3 }
+        $result = ($meaningfulWords | Select-Object -First $maxWords) -join '-'
+        return $result
+    } else {
+        $result = ConvertTo-CleanBranchName -Name $Description
+        $fallbackWords = ($result -split '-') | Where-Object { $_ } | Select-Object -First 3
+        return [string]::Join('-', $fallbackWords)
+    }
+}
+
+if ($ShortName) {
+    $branchSuffix = ConvertTo-CleanBranchName -Name $ShortName
+} else {
+    $branchSuffix = Get-BranchName -Description $featureDesc
+}
+
+if ($Timestamp -and $Number -ne 0) {
+    Write-Warning "[specify] Warning: -Number is ignored when -Timestamp is used"
+    $Number = 0
+}
+
+if ($Timestamp) {
+    $featureNum = Get-Date -Format 'yyyyMMdd-HHmmss'
+    $branchName = "$featureNum-$branchSuffix"
+} else {
+    if ($Number -eq 0) {
+        if ($DryRun -and $hasGit) {
+            $Number = Get-NextBranchNumber -SpecsDir $specsDir -SkipFetch
+        } elseif ($DryRun) {
+            $Number = (Get-HighestNumberFromSpecs -SpecsDir $specsDir) + 1
+        } elseif ($hasGit) {
+            $Number = Get-NextBranchNumber -SpecsDir $specsDir
+        } else {
+            $Number = (Get-HighestNumberFromSpecs -SpecsDir $specsDir) + 1
+        }
+    }
+
+    $featureNum = ('{0:000}' -f $Number)
+    $branchName = "$featureNum-$branchSuffix"
+}
+
+$maxBranchLength = 244
+if ($branchName.Length -gt $maxBranchLength) {
+    $prefixLength = $featureNum.Length + 1
+    $maxSuffixLength = $maxBranchLength - $prefixLength
+
+    $truncatedSuffix = $branchSuffix.Substring(0, [Math]::Min($branchSuffix.Length, $maxSuffixLength))
+    $truncatedSuffix = $truncatedSuffix -replace '-$', ''
+
+    $originalBranchName = $branchName
+    $branchName = "$featureNum-$truncatedSuffix"
+
+    Write-Warning "[specify] Branch name exceeded GitHub's 244-byte limit"
+    Write-Warning "[specify] Original: $originalBranchName ($($originalBranchName.Length) bytes)"
+    Write-Warning "[specify] Truncated to: $branchName ($($branchName.Length) bytes)"
+}
+
+$featureDir = Join-Path $specsDir $branchName
+$specFile = Join-Path $featureDir 'spec.md'
+
+if (-not $DryRun) {
+    if ($hasGit) {
+        $branchCreated = $false
+        $branchCreateError = ''
+        try {
+            $branchCreateError = git checkout -q -b $branchName 2>&1 | Out-String
+            if ($LASTEXITCODE -eq 0) {
+                $branchCreated = $true
+            }
+        } catch {
+            $branchCreateError = $_.Exception.Message
+        }
+
+        if (-not $branchCreated) {
+            $currentBranch = ''
+            try { $currentBranch = (git rev-parse --abbrev-ref HEAD 2>$null).Trim() } catch {}
+            $existingBranch = git branch --list $branchName 2>$null
+            if ($existingBranch) {
+                if ($AllowExistingBranch) {
+                    if ($currentBranch -eq $branchName) {
+                        # Already on the target branch
+                    } else {
+                        git checkout -q $branchName 2>$null | Out-Null
+                        if ($LASTEXITCODE -ne 0) {
+                            Write-Error "Error: Branch '$branchName' exists but could not be checked out. Resolve any uncommitted changes or conflicts and try again."
+                            exit 1
+                        }
+                    }
+                } elseif ($Timestamp) {
+                    Write-Error "Error: Branch '$branchName' already exists. Rerun to get a new timestamp or use a different -ShortName."
+                    exit 1
+                } else {
+                    Write-Error "Error: Branch '$branchName' already exists. Please use a different feature name or specify a different number with -Number."
+                    exit 1
+                }
+            } else {
+                if ($branchCreateError) {
+                    Write-Error "Error: Failed to create git branch '$branchName'.`n$($branchCreateError.Trim())"
+                } else {
+                    Write-Error "Error: Failed to create git branch '$branchName'. Please check your git configuration and try again."
+                }
+                exit 1
+            }
+        }
+    } else {
+        if ($Json) {
+            [Console]::Error.WriteLine("[specify] Warning: Git repository not detected; skipped branch creation for $branchName")
+        } else {
+            Write-Warning "[specify] Warning: Git repository not detected; skipped branch creation for $branchName"
+        }
+    }
+
+    New-Item -ItemType Directory -Path $featureDir -Force | Out-Null
+
+    if (-not (Test-Path -PathType Leaf $specFile)) {
+        if (Get-Command Resolve-Template -ErrorAction SilentlyContinue) {
+            $template = Resolve-Template -TemplateName 'spec-template' -RepoRoot $repoRoot
+        } else {
+            $template = $null
+        }
+        if ($template -and (Test-Path $template)) {
+            Copy-Item $template $specFile -Force
+        } else {
+            New-Item -ItemType File -Path $specFile -Force | Out-Null
+        }
+    }
+
+    $env:SPECIFY_FEATURE = $branchName
+}
+
+if ($Json) {
+    $obj = [PSCustomObject]@{
+        BRANCH_NAME = $branchName
+        SPEC_FILE = $specFile
+        FEATURE_NUM = $featureNum
+        HAS_GIT = $hasGit
+    }
+    if ($DryRun) {
+        $obj | Add-Member -NotePropertyName 'DRY_RUN' -NotePropertyValue $true
+    }
+    $obj | ConvertTo-Json -Compress
+} else {
+    Write-Output "BRANCH_NAME: $branchName"
+    Write-Output "SPEC_FILE: $specFile"
+    Write-Output "FEATURE_NUM: $featureNum"
+    Write-Output "HAS_GIT: $hasGit"
+    if (-not $DryRun) {
+        Write-Output "SPECIFY_FEATURE environment variable set to: $branchName"
+    }
+}
--- a/extensions/git/scripts/powershell/git-common.ps1
+++ b/extensions/git/scripts/powershell/git-common.ps1
@@ -0,0 +1,50 @@
+#!/usr/bin/env pwsh
+# Git-specific common functions for the git extension.
+# Extracted from scripts/powershell/common.ps1 — contains only git-specific
+# branch validation and detection logic.
+
+function Test-HasGit {
+    param([string]$RepoRoot = (Get-Location))
+    try {
+        if (-not (Test-Path (Join-Path $RepoRoot '.git'))) { return $false }
+        if (-not (Get-Command git -ErrorAction SilentlyContinue)) { return $false }
+        git -C $RepoRoot rev-parse --is-inside-work-tree 2>$null | Out-Null
+        return ($LASTEXITCODE -eq 0)
+    } catch {
+        return $false
+    }
+}
+
+function Test-FeatureBranch {
+    param(
+        [string]$Branch,
+        [bool]$HasGit = $true
+    )
+
+    # For non-git repos, we can't enforce branch naming but still provide output
+    if (-not $HasGit) {
+        Write-Warning "[specify] Warning: Git repository not detected; skipped branch validation"
+        return $true
+    }
+
+    # Reject malformed timestamps (7-digit date or no trailing slug)
+    $hasMalformedTimestamp = ($Branch -match '^[0-9]{7}-[0-9]{6}-') -or
+                            ($Branch -match '^(?:\d{7}|\d{8})-\d{6}$')
+    if ($hasMalformedTimestamp) {
+        Write-Output "ERROR: Not on a feature branch. Current branch: $Branch"
+        Write-Output "Feature branches should be named like: 001-feature-name or 20260319-143022-feature-name"
+        return $false
+    }
+
+    # Accept sequential (>=3 digits followed by hyphen) or timestamp (YYYYMMDD-HHMMSS-*)
+    $isSequential = ($Branch -match '^[0-9]{3,}-') -and (-not $hasMalformedTimestamp)
+    $isTimestamp = $Branch -match '^\d{8}-\d{6}-'
+
+    if ($isSequential -or $isTimestamp) {
+        return $true
+    }
+
+    Write-Output "ERROR: Not on a feature branch. Current branch: $Branch"
+    Write-Output "Feature branches should be named like: 001-feature-name or 20260319-143022-feature-name"
+    return $false
+}
--- a/extensions/git/scripts/powershell/initialize-repo.ps1
+++ b/extensions/git/scripts/powershell/initialize-repo.ps1
@@ -0,0 +1,69 @@
+#!/usr/bin/env pwsh
+# Git extension: initialize-repo.ps1
+# Initialize a Git repository with an initial commit.
+# Customizable — replace this script to add .gitignore templates,
+# default branch config, git-flow, LFS, signing, etc.
+$ErrorActionPreference = 'Stop'
+
+# Find project root
+function Find-ProjectRoot {
+    param([string]$StartDir)
+    $current = Resolve-Path $StartDir
+    while ($true) {
+        foreach ($marker in @('.specify', '.git')) {
+            if (Test-Path (Join-Path $current $marker)) {
+                return $current
+            }
+        }
+        $parent = Split-Path $current -Parent
+        if ($parent -eq $current) { return $null }
+        $current = $parent
+    }
+}
+
+$repoRoot = Find-ProjectRoot -StartDir $PSScriptRoot
+if (-not $repoRoot) { $repoRoot = Get-Location }
+Set-Location $repoRoot
+
+# Read commit message from extension config, fall back to default
+$commitMsg = "[Spec Kit] Initial commit"
+$configFile = Join-Path $repoRoot ".specify/extensions/git/git-config.yml"
+if (Test-Path $configFile) {
+    foreach ($line in Get-Content $configFile) {
+        if ($line -match '^init_commit_message:\s*(.+)$') {
+            $val = $matches[1].Trim() -replace '^["'']' -replace '["'']$'
+            if ($val) { $commitMsg = $val }
+            break
+        }
+    }
+}
+
+# Check if git is available
+if (-not (Get-Command git -ErrorAction SilentlyContinue)) {
+    Write-Warning "[specify] Warning: Git not found; skipped repository initialization"
+    exit 0
+}
+
+# Check if already a git repo
+try {
+    git rev-parse --is-inside-work-tree 2>$null | Out-Null
+    if ($LASTEXITCODE -eq 0) {
+        Write-Warning "[specify] Git repository already initialized; skipping"
+        exit 0
+    }
+} catch { }
+
+# Initialize
+try {
+    $out = git init -q 2>&1 | Out-String
+    if ($LASTEXITCODE -ne 0) { throw "git init failed: $out" }
+    $out = git add . 2>&1 | Out-String
+    if ($LASTEXITCODE -ne 0) { throw "git add failed: $out" }
+    $out = git commit --allow-empty -q -m $commitMsg 2>&1 | Out-String
+    if ($LASTEXITCODE -ne 0) { throw "git commit failed: $out" }
+} catch {
+    Write-Warning "[specify] Error: $_"
+    exit 1
+}
+
+Write-Host "✓ Git repository initialized"
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,6 +39,8 @@ packages = ["src/specify_cli"]
 "templates/commands" = "specify_cli/core_pack/commands"
 "scripts/bash" = "specify_cli/core_pack/scripts/bash"
 "scripts/powershell" = "specify_cli/core_pack/scripts/powershell"
+# Bundled extensions (installable via `specify extension add <name>`)
+"extensions/git" = "specify_cli/core_pack/extensions/git"

 [project.optional-dependencies]
 test = [
--- a/src/specify_cli/init.py
+++ b/src/specify_cli/init.py
@@ -604,6 +604,31 @@ def _locate_core_pack() -> Path | None:
    return None


+def _locate_bundled_extension(extension_id: str) -> Path | None:
+    """Return the path to a bundled extension, or None.
+
+    Checks the wheel's core_pack first, then falls back to the
+    source-checkout ``extensions/<id>/`` directory.
+    """
+    import re as _re
+    if not _re.match(r'^[a-z0-9-]+$', extension_id):
+        return None
+
+    core = _locate_core_pack()
+    if core is not None:
+        candidate = core / "extensions" / extension_id
+        if (candidate / "extension.yml").is_file():
+            return candidate
+
+    # Source-checkout / editable install: look relative to repo root
+    repo_root = Path(__file__).parent.parent.parent
+    candidate = repo_root / "extensions" / extension_id
+    if (candidate / "extension.yml").is_file():
+        return candidate
+
+    return None
+
+
 def _install_shared_infra(
    project_path: Path,
    script_type: str,
@@ -3024,45 +3049,58 @@ def extension_add(
                        zip_path.unlink()

            else:
-                # Install from catalog
-                catalog = ExtensionCatalog(project_root)
+                # Try bundled extensions first (shipped with spec-kit)
+                bundled_path = _locate_bundled_extension(extension)
+                if bundled_path is not None:
+                    manifest = manager.install_from_directory(bundled_path, speckit_version, priority=priority)
+                else:
+                    # Install from catalog (also resolves display names to IDs)
+                    catalog = ExtensionCatalog(project_root)

-                # Check if extension exists in catalog (supports both ID and display name)
-                ext_info, catalog_error = _resolve_catalog_extension(extension, catalog, "add")
-                if catalog_error:
-                    console.print(f"[red]Error:[/red] Could not query extension catalog: {catalog_error}")
-                    raise typer.Exit(1)
-                if not ext_info:
-                    console.print(f"[red]Error:[/red] Extension '{extension}' not found in catalog")
-                    console.print("\nSearch available extensions:")
-                    console.print("  specify extension search")
-                    raise typer.Exit(1)
+                    # Check if extension exists in catalog (supports both ID and display name)
+                    ext_info, catalog_error = _resolve_catalog_extension(extension, catalog, "add")
+                    if catalog_error:
+                        console.print(f"[red]Error:[/red] Could not query extension catalog: {catalog_error}")
+                        raise typer.Exit(1)
+                    if not ext_info:
+                        console.print(f"[red]Error:[/red] Extension '{extension}' not found in catalog")
+                        console.print("\nSearch available extensions:")
+                        console.print("  specify extension search")
+                        raise typer.Exit(1)

-                # Enforce install_allowed policy
-                if not ext_info.get("_install_allowed", True):
-                    catalog_name = ext_info.get("_catalog_name", "community")
-                    console.print(
-                        f"[red]Error:[/red] '{extension}' is available in the "
-                        f"'{catalog_name}' catalog but installation is not allowed from that catalog."
-                    )
-                    console.print(
-                        f"\nTo enable installation, add '{extension}' to an approved catalog "
-                        f"(install_allowed: true) in .specify/extension-catalogs.yml."
-                    )
-                    raise typer.Exit(1)
+                    # If catalog resolved a display name to an ID, check bundled again
+                    resolved_id = ext_info['id']
+                    if resolved_id != extension:
+                        bundled_path = _locate_bundled_extension(resolved_id)
+                        if bundled_path is not None:
+                            manifest = manager.install_from_directory(bundled_path, speckit_version, priority=priority)

-                # Download extension ZIP (use resolved ID, not original argument which may be display name)
-                extension_id = ext_info['id']
-                console.print(f"Downloading {ext_info['name']} v{ext_info.get('version', 'unknown')}...")
-                zip_path = catalog.download_extension(extension_id)
+                    if bundled_path is None:
+                        # Enforce install_allowed policy
+                        if not ext_info.get("_install_allowed", True):
+                            catalog_name = ext_info.get("_catalog_name", "community")
+                            console.print(
+                                f"[red]Error:[/red] '{extension}' is available in the "
+                                f"'{catalog_name}' catalog but installation is not allowed from that catalog."
+                            )
+                            console.print(
+                                f"\nTo enable installation, add '{extension}' to an approved catalog "
+                                f"(install_allowed: true) in .specify/extension-catalogs.yml."
+                            )
+                            raise typer.Exit(1)

-                try:
-                    # Install from downloaded ZIP
-                    manifest = manager.install_from_zip(zip_path, speckit_version, priority=priority)
-                finally:
-                    # Clean up downloaded ZIP
-                    if zip_path.exists():
-                        zip_path.unlink()
+                        # Download extension ZIP (use resolved ID, not original argument which may be display name)
+                        extension_id = ext_info['id']
+                        console.print(f"Downloading {ext_info['name']} v{ext_info.get('version', 'unknown')}...")
+                        zip_path = catalog.download_extension(extension_id)
+
+                        try:
+                            # Install from downloaded ZIP
+                            manifest = manager.install_from_zip(zip_path, speckit_version, priority=priority)
+                        finally:
+                            # Clean up downloaded ZIP
+                            if zip_path.exists():
+                                zip_path.unlink()

        console.print("\n[green]✓[/green] Extension installed successfully!")
        console.print(f"\n[bold]{manifest.name}[/bold] (v{manifest.version})")
--- a/src/specify_cli/extensions.py
+++ b/src/specify_cli/extensions.py
@@ -183,11 +183,40 @@ class ExtensionManifest:

        # Validate provides section
        provides = self.data["provides"]
-        if "commands" not in provides or not provides["commands"]:
-            raise ValidationError("Extension must provide at least one command")
+        commands = provides.get("commands", [])
+        hooks = self.data.get("hooks")

-        # Validate commands
-        for cmd in provides["commands"]:
+        if "commands" in provides and not isinstance(commands, list):
+            raise ValidationError(
+                "Invalid provides.commands: expected a list"
+            )
+        if "hooks" in self.data and not isinstance(hooks, dict):
+            raise ValidationError(
+                "Invalid hooks: expected a mapping"
+            )
+
+        has_commands = bool(commands)
+        has_hooks = bool(hooks)
+
+        if not has_commands and not has_hooks:
+            raise ValidationError(
+                "Extension must provide at least one command or hook"
+            )
+
+        # Validate hook values (if present)
+        if hooks:
+            for hook_name, hook_config in hooks.items():
+                if not isinstance(hook_config, dict):
+                    raise ValidationError(
+                        f"Invalid hook '{hook_name}': expected a mapping"
+                    )
+                if not hook_config.get("command"):
+                    raise ValidationError(
+                        f"Hook '{hook_name}' missing required 'command' field"
+                    )
+
+        # Validate commands (if present)
+        for cmd in commands:
            if "name" not in cmd or "file" not in cmd:
                raise ValidationError("Command missing 'name' or 'file'")

@@ -226,7 +255,7 @@ class ExtensionManifest:
    @property
    def commands(self) -> List[Dict[str, Any]]:
        """Get list of provided commands."""
-        return self.data["provides"]["commands"]
+        return self.data.get("provides", {}).get("commands", [])

    @property
    def hooks(self) -> Dict[str, Any]:
--- a/templates/commands/analyze.md
+++ b/templates/commands/analyze.md
@@ -13,6 +13,40 @@ $ARGUMENTS

 You **MUST** consider the user input before proceeding (if not empty).

+## Pre-Execution Checks
+
+**Check for extension hooks (before analysis)**:
+- Check if `.specify/extensions.yml` exists in the project root.
+- If it exists, read it and look for entries under the `hooks.before_analyze` key
+- If the YAML cannot be parsed or is invalid, skip hook checking silently and continue normally
+- Filter out hooks where `enabled` is explicitly `false`. Treat hooks without an `enabled` field as enabled by default.
+- For each remaining hook, do **not** attempt to interpret or evaluate hook `condition` expressions:
+  - If the hook has no `condition` field, or it is null/empty, treat the hook as executable
+  - If the hook defines a non-empty `condition`, skip the hook and leave condition evaluation to the HookExecutor implementation
+- For each executable hook, output the following based on its `optional` flag:
+  - **Optional hook** (`optional: true`):
+    ```
+    ## Extension Hooks
+
+    **Optional Pre-Hook**: {extension}
+    Command: `/{command}`
+    Description: {description}
+
+    Prompt: {prompt}
+    To execute: `/{command}`
+    ```
+  - **Mandatory hook** (`optional: false`):
+    ```
+    ## Extension Hooks
+
+    **Automatic Pre-Hook**: {extension}
+    Executing: `/{command}`
+    EXECUTE_COMMAND: {command}
+
+    Wait for the result of the hook command before proceeding to the Goal.
+    ```
+- If no hooks are registered or `.specify/extensions.yml` does not exist, skip silently
+
 ## Goal

 Identify inconsistencies, duplications, ambiguities, and underspecified items across the three core artifacts (`spec.md`, `plan.md`, `tasks.md`) before implementation. This command MUST run only after `/speckit.tasks` has successfully produced a complete `tasks.md`.
@@ -165,6 +199,37 @@ At end of report, output a concise Next Actions block:

 Ask the user: "Would you like me to suggest concrete remediation edits for the top N issues?" (Do NOT apply them automatically.)

+### 9. Check for extension hooks
+
+After reporting, check if `.specify/extensions.yml` exists in the project root.
+- If it exists, read it and look for entries under the `hooks.after_analyze` key
+- If the YAML cannot be parsed or is invalid, skip hook checking silently and continue normally
+- Filter out hooks where `enabled` is explicitly `false`. Treat hooks without an `enabled` field as enabled by default.
+- For each remaining hook, do **not** attempt to interpret or evaluate hook `condition` expressions:
+  - If the hook has no `condition` field, or it is null/empty, treat the hook as executable
+  - If the hook defines a non-empty `condition`, skip the hook and leave condition evaluation to the HookExecutor implementation
+- For each executable hook, output the following based on its `optional` flag:
+  - **Optional hook** (`optional: true`):
+    ```
+    ## Extension Hooks
+
+    **Optional Hook**: {extension}
+    Command: `/{command}`
+    Description: {description}
+
+    Prompt: {prompt}
+    To execute: `/{command}`
+    ```
+  - **Mandatory hook** (`optional: false`):
+    ```
+    ## Extension Hooks
+
+    **Automatic Hook**: {extension}
+    Executing: `/{command}`
+    EXECUTE_COMMAND: {command}
+    ```
+- If no hooks are registered or `.specify/extensions.yml` does not exist, skip silently
+
 ## Operating Principles

 ### Context Efficiency
--- a/templates/commands/checklist.md
+++ b/templates/commands/checklist.md
@@ -34,6 +34,40 @@ $ARGUMENTS

 You **MUST** consider the user input before proceeding (if not empty).

+## Pre-Execution Checks
+
+**Check for extension hooks (before checklist generation)**:
+- Check if `.specify/extensions.yml` exists in the project root.
+- If it exists, read it and look for entries under the `hooks.before_checklist` key
+- If the YAML cannot be parsed or is invalid, skip hook checking silently and continue normally
+- Filter out hooks where `enabled` is explicitly `false`. Treat hooks without an `enabled` field as enabled by default.
+- For each remaining hook, do **not** attempt to interpret or evaluate hook `condition` expressions:
+  - If the hook has no `condition` field, or it is null/empty, treat the hook as executable
+  - If the hook defines a non-empty `condition`, skip the hook and leave condition evaluation to the HookExecutor implementation
+- For each executable hook, output the following based on its `optional` flag:
+  - **Optional hook** (`optional: true`):
+    ```
+    ## Extension Hooks
+
+    **Optional Pre-Hook**: {extension}
+    Command: `/{command}`
+    Description: {description}
+
+    Prompt: {prompt}
+    To execute: `/{command}`
+    ```
+  - **Mandatory hook** (`optional: false`):
+    ```
+    ## Extension Hooks
+
+    **Automatic Pre-Hook**: {extension}
+    Executing: `/{command}`
+    EXECUTE_COMMAND: {command}
+
+    Wait for the result of the hook command before proceeding to the Execution Steps.
+    ```
+- If no hooks are registered or `.specify/extensions.yml` does not exist, skip silently
+
 ## Execution Steps

 1. **Setup**: Run `{SCRIPT}` from repo root and parse JSON for FEATURE_DIR and AVAILABLE_DOCS list.
@@ -296,3 +330,35 @@ Sample items:
 - Correct: Validation of requirement quality
 - Wrong: "Does it do X?"
 - Correct: "Is X clearly specified?"
+
+## Post-Execution Checks
+
+**Check for extension hooks (after checklist generation)**:
+Check if `.specify/extensions.yml` exists in the project root.
+- If it exists, read it and look for entries under the `hooks.after_checklist` key
+- If the YAML cannot be parsed or is invalid, skip hook checking silently and continue normally
+- Filter out hooks where `enabled` is explicitly `false`. Treat hooks without an `enabled` field as enabled by default.
+- For each remaining hook, do **not** attempt to interpret or evaluate hook `condition` expressions:
+  - If the hook has no `condition` field, or it is null/empty, treat the hook as executable
+  - If the hook defines a non-empty `condition`, skip the hook and leave condition evaluation to the HookExecutor implementation
+- For each executable hook, output the following based on its `optional` flag:
+  - **Optional hook** (`optional: true`):
+    ```
+    ## Extension Hooks
+
+    **Optional Hook**: {extension}
+    Command: `/{command}`
+    Description: {description}
+
+    Prompt: {prompt}
+    To execute: `/{command}`
+    ```
+  - **Mandatory hook** (`optional: false`):
+    ```
+    ## Extension Hooks
+
+    **Automatic Hook**: {extension}
+    Executing: `/{command}`
+    EXECUTE_COMMAND: {command}
+    ```
+- If no hooks are registered or `.specify/extensions.yml` does not exist, skip silently
--- a/templates/commands/clarify.md
+++ b/templates/commands/clarify.md
@@ -17,6 +17,40 @@ $ARGUMENTS

 You **MUST** consider the user input before proceeding (if not empty).

+## Pre-Execution Checks
+
+**Check for extension hooks (before clarification)**:
+- Check if `.specify/extensions.yml` exists in the project root.
+- If it exists, read it and look for entries under the `hooks.before_clarify` key
+- If the YAML cannot be parsed or is invalid, skip hook checking silently and continue normally
+- Filter out hooks where `enabled` is explicitly `false`. Treat hooks without an `enabled` field as enabled by default.
+- For each remaining hook, do **not** attempt to interpret or evaluate hook `condition` expressions:
+  - If the hook has no `condition` field, or it is null/empty, treat the hook as executable
+  - If the hook defines a non-empty `condition`, skip the hook and leave condition evaluation to the HookExecutor implementation
+- For each executable hook, output the following based on its `optional` flag:
+  - **Optional hook** (`optional: true`):
+    ```
+    ## Extension Hooks
+
+    **Optional Pre-Hook**: {extension}
+    Command: `/{command}`
+    Description: {description}
+
+    Prompt: {prompt}
+    To execute: `/{command}`
+    ```
+  - **Mandatory hook** (`optional: false`):
+    ```
+    ## Extension Hooks
+
+    **Automatic Pre-Hook**: {extension}
+    Executing: `/{command}`
+    EXECUTE_COMMAND: {command}
+
+    Wait for the result of the hook command before proceeding to the Outline.
+    ```
+- If no hooks are registered or `.specify/extensions.yml` does not exist, skip silently
+
 ## Outline

 Goal: Detect and reduce ambiguity or missing decision points in the active feature specification and record the clarifications directly in the spec file.
@@ -182,3 +216,35 @@ Behavior rules:
 - If quota reached with unresolved high-impact categories remaining, explicitly flag them under Deferred with rationale.

 Context for prioritization: {ARGS}
+
+## Post-Execution Checks
+
+**Check for extension hooks (after clarification)**:
+Check if `.specify/extensions.yml` exists in the project root.
+- If it exists, read it and look for entries under the `hooks.after_clarify` key
+- If the YAML cannot be parsed or is invalid, skip hook checking silently and continue normally
+- Filter out hooks where `enabled` is explicitly `false`. Treat hooks without an `enabled` field as enabled by default.
+- For each remaining hook, do **not** attempt to interpret or evaluate hook `condition` expressions:
+  - If the hook has no `condition` field, or it is null/empty, treat the hook as executable
+  - If the hook defines a non-empty `condition`, skip the hook and leave condition evaluation to the HookExecutor implementation
+- For each executable hook, output the following based on its `optional` flag:
+  - **Optional hook** (`optional: true`):
+    ```
+    ## Extension Hooks
+
+    **Optional Hook**: {extension}
+    Command: `/{command}`
+    Description: {description}
+
+    Prompt: {prompt}
+    To execute: `/{command}`
+    ```
+  - **Mandatory hook** (`optional: false`):
+    ```
+    ## Extension Hooks
+
+    **Automatic Hook**: {extension}
+    Executing: `/{command}`
+    EXECUTE_COMMAND: {command}
+    ```
+- If no hooks are registered or `.specify/extensions.yml` does not exist, skip silently
--- a/templates/commands/constitution.md
+++ b/templates/commands/constitution.md
@@ -14,6 +14,40 @@ $ARGUMENTS

 You **MUST** consider the user input before proceeding (if not empty).

+## Pre-Execution Checks
+
+**Check for extension hooks (before constitution update)**:
+- Check if `.specify/extensions.yml` exists in the project root.
+- If it exists, read it and look for entries under the `hooks.before_constitution` key
+- If the YAML cannot be parsed or is invalid, skip hook checking silently and continue normally
+- Filter out hooks where `enabled` is explicitly `false`. Treat hooks without an `enabled` field as enabled by default.
+- For each remaining hook, do **not** attempt to interpret or evaluate hook `condition` expressions:
+  - If the hook has no `condition` field, or it is null/empty, treat the hook as executable
+  - If the hook defines a non-empty `condition`, skip the hook and leave condition evaluation to the HookExecutor implementation
+- For each executable hook, output the following based on its `optional` flag:
+  - **Optional hook** (`optional: true`):
+    ```
+    ## Extension Hooks
+
+    **Optional Pre-Hook**: {extension}
+    Command: `/{command}`
+    Description: {description}
+
+    Prompt: {prompt}
+    To execute: `/{command}`
+    ```
+  - **Mandatory hook** (`optional: false`):
+    ```
+    ## Extension Hooks
+
+    **Automatic Pre-Hook**: {extension}
+    Executing: `/{command}`
+    EXECUTE_COMMAND: {command}
+
+    Wait for the result of the hook command before proceeding to the Outline.
+    ```
+- If no hooks are registered or `.specify/extensions.yml` does not exist, skip silently
+
 ## Outline

 You are updating the project constitution at `.specify/memory/constitution.md`. This file is a TEMPLATE containing placeholder tokens in square brackets (e.g. `[PROJECT_NAME]`, `[PRINCIPLE_1_NAME]`). Your job is to (a) collect/derive concrete values, (b) fill the template precisely, and (c) propagate any amendments across dependent artifacts.
@@ -82,3 +116,35 @@ If the user supplies partial updates (e.g., only one principle revision), still
 If critical info missing (e.g., ratification date truly unknown), insert `TODO(<FIELD_NAME>): explanation` and include in the Sync Impact Report under deferred items.

 Do not create a new template; always operate on the existing `.specify/memory/constitution.md` file.
+
+## Post-Execution Checks
+
+**Check for extension hooks (after constitution update)**:
+Check if `.specify/extensions.yml` exists in the project root.
+- If it exists, read it and look for entries under the `hooks.after_constitution` key
+- If the YAML cannot be parsed or is invalid, skip hook checking silently and continue normally
+- Filter out hooks where `enabled` is explicitly `false`. Treat hooks without an `enabled` field as enabled by default.
+- For each remaining hook, do **not** attempt to interpret or evaluate hook `condition` expressions:
+  - If the hook has no `condition` field, or it is null/empty, treat the hook as executable
+  - If the hook defines a non-empty `condition`, skip the hook and leave condition evaluation to the HookExecutor implementation
+- For each executable hook, output the following based on its `optional` flag:
+  - **Optional hook** (`optional: true`):
+    ```
+    ## Extension Hooks
+
+    **Optional Hook**: {extension}
+    Command: `/{command}`
+    Description: {description}
+
+    Prompt: {prompt}
+    To execute: `/{command}`
+    ```
+  - **Mandatory hook** (`optional: false`):
+    ```
+    ## Extension Hooks
+
+    **Automatic Hook**: {extension}
+    Executing: `/{command}`
+    EXECUTE_COMMAND: {command}
+    ```
+- If no hooks are registered or `.specify/extensions.yml` does not exist, skip silently
--- a/templates/commands/taskstoissues.md
+++ b/templates/commands/taskstoissues.md
@@ -14,6 +14,40 @@ $ARGUMENTS

 You **MUST** consider the user input before proceeding (if not empty).

+## Pre-Execution Checks
+
+**Check for extension hooks (before tasks-to-issues conversion)**:
+- Check if `.specify/extensions.yml` exists in the project root.
+- If it exists, read it and look for entries under the `hooks.before_taskstoissues` key
+- If the YAML cannot be parsed or is invalid, skip hook checking silently and continue normally
+- Filter out hooks where `enabled` is explicitly `false`. Treat hooks without an `enabled` field as enabled by default.
+- For each remaining hook, do **not** attempt to interpret or evaluate hook `condition` expressions:
+  - If the hook has no `condition` field, or it is null/empty, treat the hook as executable
+  - If the hook defines a non-empty `condition`, skip the hook and leave condition evaluation to the HookExecutor implementation
+- For each executable hook, output the following based on its `optional` flag:
+  - **Optional hook** (`optional: true`):
+    ```
+    ## Extension Hooks
+
+    **Optional Pre-Hook**: {extension}
+    Command: `/{command}`
+    Description: {description}
+
+    Prompt: {prompt}
+    To execute: `/{command}`
+    ```
+  - **Mandatory hook** (`optional: false`):
+    ```
+    ## Extension Hooks
+
+    **Automatic Pre-Hook**: {extension}
+    Executing: `/{command}`
+    EXECUTE_COMMAND: {command}
+
+    Wait for the result of the hook command before proceeding to the Outline.
+    ```
+- If no hooks are registered or `.specify/extensions.yml` does not exist, skip silently
+
 ## Outline

 1. Run `{SCRIPT}` from repo root and parse FEATURE_DIR and AVAILABLE_DOCS list. All paths must be absolute. For single quotes in args like "I'm Groot", use escape syntax: e.g 'I'\''m Groot' (or double-quote if possible: "I'm Groot").
@@ -31,3 +65,35 @@ git config --get remote.origin.url

 > [!CAUTION]
 > UNDER NO CIRCUMSTANCES EVER CREATE ISSUES IN REPOSITORIES THAT DO NOT MATCH THE REMOTE URL
+
+## Post-Execution Checks
+
+**Check for extension hooks (after tasks-to-issues conversion)**:
+Check if `.specify/extensions.yml` exists in the project root.
+- If it exists, read it and look for entries under the `hooks.after_taskstoissues` key
+- If the YAML cannot be parsed or is invalid, skip hook checking silently and continue normally
+- Filter out hooks where `enabled` is explicitly `false`. Treat hooks without an `enabled` field as enabled by default.
+- For each remaining hook, do **not** attempt to interpret or evaluate hook `condition` expressions:
+  - If the hook has no `condition` field, or it is null/empty, treat the hook as executable
+  - If the hook defines a non-empty `condition`, skip the hook and leave condition evaluation to the HookExecutor implementation
+- For each executable hook, output the following based on its `optional` flag:
+  - **Optional hook** (`optional: true`):
+    ```
+    ## Extension Hooks
+
+    **Optional Hook**: {extension}
+    Command: `/{command}`
+    Description: {description}
+
+    Prompt: {prompt}
+    To execute: `/{command}`
+    ```
+  - **Mandatory hook** (`optional: false`):
+    ```
+    ## Extension Hooks
+
+    **Automatic Hook**: {extension}
+    Executing: `/{command}`
+    EXECUTE_COMMAND: {command}
+    ```
+- If no hooks are registered or `.specify/extensions.yml` does not exist, skip silently
--- a/tests/extensions/init.py
+++ b/tests/extensions/init.py
@@ -0,0 +1 @@
+"""Extensions test package."""
--- a/tests/extensions/git/init.py
+++ b/tests/extensions/git/init.py
@@ -0,0 +1 @@
+"""Tests for the bundled git extension."""
--- a/tests/extensions/git/test_git_extension.py
+++ b/tests/extensions/git/test_git_extension.py
@@ -0,0 +1,601 @@
+"""
+Tests for the bundled git extension (extensions/git/).
+
+Validates:
+- extension.yml manifest
+- Bash scripts (create-new-feature.sh, initialize-repo.sh, auto-commit.sh, git-common.sh)
+- PowerShell scripts (where pwsh is available)
+- Config reading from git-config.yml
+- Extension install via ExtensionManager
+"""
+
+import json
+import os
+import re
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+PROJECT_ROOT = Path(__file__).resolve().parent.parent.parent.parent
+EXT_DIR = PROJECT_ROOT / "extensions" / "git"
+EXT_BASH = EXT_DIR / "scripts" / "bash"
+EXT_PS = EXT_DIR / "scripts" / "powershell"
+CORE_COMMON_SH = PROJECT_ROOT / "scripts" / "bash" / "common.sh"
+CORE_COMMON_PS = PROJECT_ROOT / "scripts" / "powershell" / "common.ps1"
+
+HAS_PWSH = shutil.which("pwsh") is not None
+
+
+# ── Helpers ──────────────────────────────────────────────────────────────────
+
+
+def _init_git(path: Path) -> None:
+    """Initialize a git repo with a dummy commit."""
+    subprocess.run(["git", "init", "-q"], cwd=path, check=True)
+    subprocess.run(["git", "config", "user.email", "test@example.com"], cwd=path, check=True)
+    subprocess.run(["git", "config", "user.name", "Test User"], cwd=path, check=True)
+    subprocess.run(
+        ["git", "commit", "--allow-empty", "-m", "seed", "-q"],
+        cwd=path,
+        check=True,
+    )
+
+
+def _setup_project(tmp_path: Path, *, git: bool = True) -> Path:
+    """Create a project directory with core scripts and .specify."""
+    # Core scripts (needed by extension scripts that source common.sh)
+    bash_dir = tmp_path / "scripts" / "bash"
+    bash_dir.mkdir(parents=True)
+    shutil.copy(CORE_COMMON_SH, bash_dir / "common.sh")
+
+    ps_dir = tmp_path / "scripts" / "powershell"
+    ps_dir.mkdir(parents=True)
+    shutil.copy(CORE_COMMON_PS, ps_dir / "common.ps1")
+
+    # .specify structure
+    (tmp_path / ".specify" / "templates").mkdir(parents=True)
+
+    # Extension scripts (as if installed)
+    ext_bash = tmp_path / ".specify" / "extensions" / "git" / "scripts" / "bash"
+    ext_bash.mkdir(parents=True)
+    for f in EXT_BASH.iterdir():
+        dest = ext_bash / f.name
+        shutil.copy(f, dest)
+        dest.chmod(0o755)
+
+    ext_ps = tmp_path / ".specify" / "extensions" / "git" / "scripts" / "powershell"
+    ext_ps.mkdir(parents=True)
+    for f in EXT_PS.iterdir():
+        shutil.copy(f, ext_ps / f.name)
+
+    # Copy extension.yml
+    shutil.copy(EXT_DIR / "extension.yml", tmp_path / ".specify" / "extensions" / "git" / "extension.yml")
+
+    if git:
+        _init_git(tmp_path)
+
+    return tmp_path
+
+
+def _write_config(project: Path, content: str) -> Path:
+    """Write git-config.yml into the extension config directory."""
+    config_path = project / ".specify" / "extensions" / "git" / "git-config.yml"
+    config_path.write_text(content, encoding="utf-8")
+    return config_path
+
+
+# Git identity env vars for CI runners without global git config
+_GIT_ENV = {
+    "GIT_AUTHOR_NAME": "Test User",
+    "GIT_AUTHOR_EMAIL": "test@example.com",
+    "GIT_COMMITTER_NAME": "Test User",
+    "GIT_COMMITTER_EMAIL": "test@example.com",
+}
+
+
+def _run_bash(script_name: str, cwd: Path, *args: str, env_extra: dict | None = None) -> subprocess.CompletedProcess:
+    """Run an extension bash script."""
+    script = cwd / ".specify" / "extensions" / "git" / "scripts" / "bash" / script_name
+    env = {**os.environ, **_GIT_ENV, **(env_extra or {})}
+    return subprocess.run(
+        ["bash", str(script), *args],
+        cwd=cwd,
+        capture_output=True,
+        text=True,
+        env=env,
+    )
+
+
+def _run_pwsh(script_name: str, cwd: Path, *args: str) -> subprocess.CompletedProcess:
+    """Run an extension PowerShell script."""
+    script = cwd / ".specify" / "extensions" / "git" / "scripts" / "powershell" / script_name
+    env = {**os.environ, **_GIT_ENV}
+    return subprocess.run(
+        ["pwsh", "-NoProfile", "-File", str(script), *args],
+        cwd=cwd,
+        capture_output=True,
+        text=True,
+        env=env,
+    )
+
+
+# ── Manifest Tests ───────────────────────────────────────────────────────────
+
+
+class TestGitExtensionManifest:
+    def test_manifest_validates(self):
+        """extension.yml passes manifest validation."""
+        from specify_cli.extensions import ExtensionManifest
+
+        m = ExtensionManifest(EXT_DIR / "extension.yml")
+        assert m.id == "git"
+        assert m.version == "1.0.0"
+
+    def test_manifest_commands(self):
+        """Manifest declares expected commands."""
+        from specify_cli.extensions import ExtensionManifest
+
+        m = ExtensionManifest(EXT_DIR / "extension.yml")
+        names = [c["name"] for c in m.commands]
+        assert "speckit.git.feature" in names
+        assert "speckit.git.validate" in names
+        assert "speckit.git.remote" in names
+        assert "speckit.git.initialize" in names
+        assert "speckit.git.commit" in names
+
+    def test_manifest_hooks(self):
+        """Manifest declares expected hooks."""
+        from specify_cli.extensions import ExtensionManifest
+
+        m = ExtensionManifest(EXT_DIR / "extension.yml")
+        assert "before_constitution" in m.hooks
+        assert "before_specify" in m.hooks
+        assert "after_specify" in m.hooks
+        assert "after_implement" in m.hooks
+        assert m.hooks["before_constitution"]["command"] == "speckit.git.initialize"
+        assert m.hooks["before_specify"]["command"] == "speckit.git.feature"
+
+    def test_manifest_command_files_exist(self):
+        """All command files referenced in the manifest exist."""
+        from specify_cli.extensions import ExtensionManifest
+
+        m = ExtensionManifest(EXT_DIR / "extension.yml")
+        for cmd in m.commands:
+            cmd_path = EXT_DIR / cmd["file"]
+            assert cmd_path.is_file(), f"Missing command file: {cmd['file']}"
+
+
+# ── Install Tests ────────────────────────────────────────────────────────────
+
+
+class TestGitExtensionInstall:
+    def test_install_from_directory(self, tmp_path: Path):
+        """Extension installs via ExtensionManager.install_from_directory."""
+        from specify_cli.extensions import ExtensionManager
+
+        (tmp_path / ".specify").mkdir()
+        manager = ExtensionManager(tmp_path)
+        manifest = manager.install_from_directory(EXT_DIR, "0.5.0", register_commands=False)
+        assert manifest.id == "git"
+        assert manager.registry.is_installed("git")
+
+    def test_install_copies_scripts(self, tmp_path: Path):
+        """Extension install copies script files."""
+        from specify_cli.extensions import ExtensionManager
+
+        (tmp_path / ".specify").mkdir()
+        manager = ExtensionManager(tmp_path)
+        manager.install_from_directory(EXT_DIR, "0.5.0", register_commands=False)
+
+        ext_installed = tmp_path / ".specify" / "extensions" / "git"
+        assert (ext_installed / "scripts" / "bash" / "create-new-feature.sh").is_file()
+        assert (ext_installed / "scripts" / "bash" / "initialize-repo.sh").is_file()
+        assert (ext_installed / "scripts" / "bash" / "auto-commit.sh").is_file()
+        assert (ext_installed / "scripts" / "bash" / "git-common.sh").is_file()
+        assert (ext_installed / "scripts" / "powershell" / "create-new-feature.ps1").is_file()
+        assert (ext_installed / "scripts" / "powershell" / "initialize-repo.ps1").is_file()
+        assert (ext_installed / "scripts" / "powershell" / "auto-commit.ps1").is_file()
+        assert (ext_installed / "scripts" / "powershell" / "git-common.ps1").is_file()
+
+    def test_bundled_extension_locator(self):
+        """_locate_bundled_extension finds the git extension."""
+        from specify_cli import _locate_bundled_extension
+
+        path = _locate_bundled_extension("git")
+        assert path is not None
+        assert (path / "extension.yml").is_file()
+
+
+# ── initialize-repo.sh Tests ─────────────────────────────────────────────────
+
+
+class TestInitializeRepoBash:
+    def test_initializes_git_repo(self, tmp_path: Path):
+        """initialize-repo.sh creates a git repo with initial commit."""
+        project = _setup_project(tmp_path, git=False)
+        result = _run_bash("initialize-repo.sh", project)
+        assert result.returncode == 0, result.stderr
+
+        # Verify git repo exists
+        assert (project / ".git").exists()
+
+        # Verify at least one commit exists
+        log = subprocess.run(
+            ["git", "log", "--oneline", "-1"],
+            cwd=project, capture_output=True, text=True,
+        )
+        assert log.returncode == 0
+
+    def test_skips_if_already_git_repo(self, tmp_path: Path):
+        """initialize-repo.sh skips if already a git repo."""
+        project = _setup_project(tmp_path, git=True)
+        result = _run_bash("initialize-repo.sh", project)
+        assert result.returncode == 0
+        assert "already initialized" in result.stderr.lower()
+
+    def test_custom_commit_message(self, tmp_path: Path):
+        """initialize-repo.sh reads custom commit message from config."""
+        project = _setup_project(tmp_path, git=False)
+        _write_config(project, 'init_commit_message: "Custom init message"\n')
+
+        result = _run_bash("initialize-repo.sh", project)
+        assert result.returncode == 0
+
+        log = subprocess.run(
+            ["git", "log", "--oneline", "-1"],
+            cwd=project, capture_output=True, text=True,
+        )
+        assert "Custom init message" in log.stdout
+
+
+@pytest.mark.skipif(not HAS_PWSH, reason="pwsh not available")
+class TestInitializeRepoPowerShell:
+    def test_initializes_git_repo(self, tmp_path: Path):
+        """initialize-repo.ps1 creates a git repo with initial commit."""
+        project = _setup_project(tmp_path, git=False)
+        result = _run_pwsh("initialize-repo.ps1", project)
+        assert result.returncode == 0, result.stderr
+        assert (project / ".git").exists()
+
+    def test_skips_if_already_git_repo(self, tmp_path: Path):
+        """initialize-repo.ps1 skips if already a git repo."""
+        project = _setup_project(tmp_path, git=True)
+        result = _run_pwsh("initialize-repo.ps1", project)
+        assert result.returncode == 0
+
+
+# ── create-new-feature.sh Tests ──────────────────────────────────────────────
+
+
+class TestCreateFeatureBash:
+    def test_creates_branch_sequential(self, tmp_path: Path):
+        """Extension create-new-feature.sh creates sequential branch."""
+        project = _setup_project(tmp_path)
+        result = _run_bash(
+            "create-new-feature.sh", project,
+            "--json", "--short-name", "user-auth", "Add user authentication",
+        )
+        assert result.returncode == 0, result.stderr
+        data = json.loads(result.stdout)
+        assert data["BRANCH_NAME"] == "001-user-auth"
+        assert "SPEC_FILE" in data
+        assert data["FEATURE_NUM"] == "001"
+
+    def test_creates_branch_timestamp(self, tmp_path: Path):
+        """Extension create-new-feature.sh creates timestamp branch."""
+        project = _setup_project(tmp_path)
+        result = _run_bash(
+            "create-new-feature.sh", project,
+            "--json", "--timestamp", "--short-name", "feat", "Feature",
+        )
+        assert result.returncode == 0, result.stderr
+        data = json.loads(result.stdout)
+        assert re.match(r"^\d{8}-\d{6}-feat$", data["BRANCH_NAME"])
+
+    def test_creates_spec_dir(self, tmp_path: Path):
+        """create-new-feature.sh creates specs directory and spec.md."""
+        project = _setup_project(tmp_path)
+        result = _run_bash(
+            "create-new-feature.sh", project,
+            "--json", "--short-name", "test-feat", "Test feature",
+        )
+        assert result.returncode == 0, result.stderr
+        data = json.loads(result.stdout)
+        spec_file = Path(data["SPEC_FILE"])
+        assert spec_file.exists(), f"spec.md not created at {spec_file}"
+
+    def test_increments_from_existing_specs(self, tmp_path: Path):
+        """Sequential numbering increments past existing spec directories."""
+        project = _setup_project(tmp_path)
+        (project / "specs" / "001-first").mkdir(parents=True)
+        (project / "specs" / "002-second").mkdir(parents=True)
+
+        result = _run_bash(
+            "create-new-feature.sh", project,
+            "--json", "--short-name", "third", "Third feature",
+        )
+        assert result.returncode == 0, result.stderr
+        data = json.loads(result.stdout)
+        assert data["FEATURE_NUM"] == "003"
+
+    def test_no_git_graceful_degradation(self, tmp_path: Path):
+        """create-new-feature.sh works without git (creates spec dir only)."""
+        project = _setup_project(tmp_path, git=False)
+        result = _run_bash(
+            "create-new-feature.sh", project,
+            "--json", "--short-name", "no-git", "No git feature",
+        )
+        assert result.returncode == 0, result.stderr
+        assert "Warning" in result.stderr
+        data = json.loads(result.stdout)
+        spec_file = Path(data["SPEC_FILE"])
+        assert spec_file.exists()
+
+    def test_dry_run(self, tmp_path: Path):
+        """--dry-run computes branch name without creating anything."""
+        project = _setup_project(tmp_path)
+        result = _run_bash(
+            "create-new-feature.sh", project,
+            "--json", "--dry-run", "--short-name", "dry", "Dry run test",
+        )
+        assert result.returncode == 0, result.stderr
+        data = json.loads(result.stdout)
+        assert data.get("DRY_RUN") is True
+        assert not (project / "specs" / data["BRANCH_NAME"]).exists()
+
+
+@pytest.mark.skipif(not HAS_PWSH, reason="pwsh not available")
+class TestCreateFeaturePowerShell:
+    def test_creates_branch_sequential(self, tmp_path: Path):
+        """Extension create-new-feature.ps1 creates sequential branch."""
+        project = _setup_project(tmp_path)
+        result = _run_pwsh(
+            "create-new-feature.ps1", project,
+            "-Json", "-ShortName", "user-auth", "Add user authentication",
+        )
+        assert result.returncode == 0, result.stderr
+        data = json.loads(result.stdout)
+        assert data["BRANCH_NAME"] == "001-user-auth"
+
+    def test_creates_branch_timestamp(self, tmp_path: Path):
+        """Extension create-new-feature.ps1 creates timestamp branch."""
+        project = _setup_project(tmp_path)
+        result = _run_pwsh(
+            "create-new-feature.ps1", project,
+            "-Json", "-Timestamp", "-ShortName", "feat", "Feature",
+        )
+        assert result.returncode == 0, result.stderr
+        data = json.loads(result.stdout)
+        assert re.match(r"^\d{8}-\d{6}-feat$", data["BRANCH_NAME"])
+
+    def test_no_git_graceful_degradation(self, tmp_path: Path):
+        """create-new-feature.ps1 works without git."""
+        project = _setup_project(tmp_path, git=False)
+        result = _run_pwsh(
+            "create-new-feature.ps1", project,
+            "-Json", "-ShortName", "no-git", "No git feature",
+        )
+        assert result.returncode == 0, result.stderr
+        # pwsh may prefix warnings to stdout; find the JSON line
+        json_line = [l for l in result.stdout.splitlines() if l.strip().startswith("{")]
+        assert json_line, f"No JSON in output: {result.stdout}"
+        data = json.loads(json_line[-1])
+        assert Path(data["SPEC_FILE"]).exists()
+
+
+# ── auto-commit.sh Tests ─────────────────────────────────────────────────────
+
+
+class TestAutoCommitBash:
+    def test_disabled_by_default(self, tmp_path: Path):
+        """auto-commit.sh exits silently when config is all false."""
+        project = _setup_project(tmp_path)
+        _write_config(project, "auto_commit:\n  default: false\n")
+        result = _run_bash("auto-commit.sh", project, "after_specify")
+        assert result.returncode == 0
+        # Should not have created any new commits
+        log = subprocess.run(
+            ["git", "log", "--oneline"],
+            cwd=project, capture_output=True, text=True,
+        )
+        assert log.stdout.strip().count("\n") == 0  # only the seed commit
+
+    def test_enabled_per_command(self, tmp_path: Path):
+        """auto-commit.sh commits when per-command key is enabled."""
+        project = _setup_project(tmp_path)
+        _write_config(project, (
+            "auto_commit:\n"
+            "  default: false\n"
+            "  after_specify:\n"
+            "    enabled: true\n"
+            '    message: "test commit after specify"\n'
+        ))
+        # Create a file to commit
+        (project / "specs" / "001-test" / "spec.md").parent.mkdir(parents=True)
+        (project / "specs" / "001-test" / "spec.md").write_text("test spec")
+
+        result = _run_bash("auto-commit.sh", project, "after_specify")
+        assert result.returncode == 0
+
+        log = subprocess.run(
+            ["git", "log", "--oneline", "-1"],
+            cwd=project, capture_output=True, text=True,
+        )
+        assert "test commit after specify" in log.stdout
+
+    def test_custom_message(self, tmp_path: Path):
+        """auto-commit.sh uses the per-command message."""
+        project = _setup_project(tmp_path)
+        _write_config(project, (
+            "auto_commit:\n"
+            "  default: false\n"
+            "  after_plan:\n"
+            "    enabled: true\n"
+            '    message: "[Project] Plan complete"\n'
+        ))
+        (project / "new-file.txt").write_text("content")
+
+        result = _run_bash("auto-commit.sh", project, "after_plan")
+        assert result.returncode == 0
+
+        log = subprocess.run(
+            ["git", "log", "--oneline", "-1"],
+            cwd=project, capture_output=True, text=True,
+        )
+        assert "[Project] Plan complete" in log.stdout
+
+    def test_default_true_with_no_event_key(self, tmp_path: Path):
+        """auto-commit.sh uses default: true when event key is absent."""
+        project = _setup_project(tmp_path)
+        _write_config(project, "auto_commit:\n  default: true\n")
+        (project / "new-file.txt").write_text("content")
+
+        result = _run_bash("auto-commit.sh", project, "after_tasks")
+        assert result.returncode == 0
+
+        log = subprocess.run(
+            ["git", "log", "--oneline", "-1"],
+            cwd=project, capture_output=True, text=True,
+        )
+        assert "Auto-commit after tasks" in log.stdout
+
+    def test_no_changes_skips(self, tmp_path: Path):
+        """auto-commit.sh skips when there are no changes."""
+        project = _setup_project(tmp_path)
+        _write_config(project, (
+            "auto_commit:\n"
+            "  default: false\n"
+            "  after_specify:\n"
+            "    enabled: true\n"
+            '    message: "should not appear"\n'
+        ))
+        # Commit all existing files so nothing is dirty
+        subprocess.run(["git", "add", "."], cwd=project, check=True)
+        subprocess.run(["git", "commit", "-m", "setup", "-q"], cwd=project, check=True)
+
+        result = _run_bash("auto-commit.sh", project, "after_specify")
+        assert result.returncode == 0
+        assert "No changes" in result.stderr
+
+    def test_no_config_file_skips(self, tmp_path: Path):
+        """auto-commit.sh exits silently when no config file exists."""
+        project = _setup_project(tmp_path)
+        # Remove config if it was copied
+        config = project / ".specify" / "extensions" / "git" / "git-config.yml"
+        config.unlink(missing_ok=True)
+
+        result = _run_bash("auto-commit.sh", project, "after_specify")
+        assert result.returncode == 0
+
+    def test_no_git_repo_skips(self, tmp_path: Path):
+        """auto-commit.sh skips when not in a git repo."""
+        project = _setup_project(tmp_path, git=False)
+        _write_config(project, "auto_commit:\n  default: true\n")
+        result = _run_bash("auto-commit.sh", project, "after_specify")
+        assert result.returncode == 0
+        assert "not a Git repository" in result.stderr.lower() or "Warning" in result.stderr
+
+    def test_requires_event_name_argument(self, tmp_path: Path):
+        """auto-commit.sh fails without event name argument."""
+        project = _setup_project(tmp_path)
+        result = _run_bash("auto-commit.sh", project)
+        assert result.returncode != 0
+
+
+@pytest.mark.skipif(not HAS_PWSH, reason="pwsh not available")
+class TestAutoCommitPowerShell:
+    def test_disabled_by_default(self, tmp_path: Path):
+        """auto-commit.ps1 exits silently when config is all false."""
+        project = _setup_project(tmp_path)
+        _write_config(project, "auto_commit:\n  default: false\n")
+        result = _run_pwsh("auto-commit.ps1", project, "after_specify")
+        assert result.returncode == 0
+
+    def test_enabled_per_command(self, tmp_path: Path):
+        """auto-commit.ps1 commits when per-command key is enabled."""
+        project = _setup_project(tmp_path)
+        _write_config(project, (
+            "auto_commit:\n"
+            "  default: false\n"
+            "  after_specify:\n"
+            "    enabled: true\n"
+            '    message: "ps commit"\n'
+        ))
+        (project / "specs" / "001-test").mkdir(parents=True)
+        (project / "specs" / "001-test" / "spec.md").write_text("test")
+
+        result = _run_pwsh("auto-commit.ps1", project, "after_specify")
+        assert result.returncode == 0
+
+        log = subprocess.run(
+            ["git", "log", "--oneline", "-1"],
+            cwd=project, capture_output=True, text=True,
+        )
+        assert "ps commit" in log.stdout
+
+
+# ── git-common.sh Tests ──────────────────────────────────────────────────────
+
+
+class TestGitCommonBash:
+    def test_has_git_true(self, tmp_path: Path):
+        """has_git returns 0 in a git repo."""
+        project = _setup_project(tmp_path, git=True)
+        script = project / ".specify" / "extensions" / "git" / "scripts" / "bash" / "git-common.sh"
+        result = subprocess.run(
+            ["bash", "-c", f'source "{script}" && has_git "{project}"'],
+            capture_output=True, text=True,
+        )
+        assert result.returncode == 0
+
+    def test_has_git_false(self, tmp_path: Path):
+        """has_git returns non-zero outside a git repo."""
+        project = _setup_project(tmp_path, git=False)
+        script = project / ".specify" / "extensions" / "git" / "scripts" / "bash" / "git-common.sh"
+        result = subprocess.run(
+            ["bash", "-c", f'source "{script}" && has_git "{project}"'],
+            capture_output=True, text=True,
+        )
+        assert result.returncode != 0
+
+    def test_check_feature_branch_sequential(self, tmp_path: Path):
+        """check_feature_branch accepts sequential branch names."""
+        project = _setup_project(tmp_path)
+        script = project / ".specify" / "extensions" / "git" / "scripts" / "bash" / "git-common.sh"
+        result = subprocess.run(
+            ["bash", "-c", f'source "{script}" && check_feature_branch "001-my-feature" "true"'],
+            capture_output=True, text=True,
+        )
+        assert result.returncode == 0
+
+    def test_check_feature_branch_timestamp(self, tmp_path: Path):
+        """check_feature_branch accepts timestamp branch names."""
+        project = _setup_project(tmp_path)
+        script = project / ".specify" / "extensions" / "git" / "scripts" / "bash" / "git-common.sh"
+        result = subprocess.run(
+            ["bash", "-c", f'source "{script}" && check_feature_branch "20260319-143022-feat" "true"'],
+            capture_output=True, text=True,
+        )
+        assert result.returncode == 0
+
+    def test_check_feature_branch_rejects_main(self, tmp_path: Path):
+        """check_feature_branch rejects non-feature branch names."""
+        project = _setup_project(tmp_path)
+        script = project / ".specify" / "extensions" / "git" / "scripts" / "bash" / "git-common.sh"
+        result = subprocess.run(
+            ["bash", "-c", f'source "{script}" && check_feature_branch "main" "true"'],
+            capture_output=True, text=True,
+        )
+        assert result.returncode != 0
+
+    def test_check_feature_branch_rejects_malformed_timestamp(self, tmp_path: Path):
+        """check_feature_branch rejects malformed timestamps (7-digit date)."""
+        project = _setup_project(tmp_path)
+        script = project / ".specify" / "extensions" / "git" / "scripts" / "bash" / "git-common.sh"
+        result = subprocess.run(
+            ["bash", "-c", f'source "{script}" && check_feature_branch "2026031-143022-feat" "true"'],
+            capture_output=True, text=True,
+        )
+        assert result.returncode != 0
--- a/tests/test_extensions.py
+++ b/tests/test_extensions.py
@@ -255,17 +255,66 @@ class TestExtensionManifest:
        with pytest.raises(ValidationError, match="Invalid command name"):
            ExtensionManifest(manifest_path)

-    def test_no_commands(self, temp_dir, valid_manifest_data):
-        """Test manifest with no commands provided."""
+    def test_no_commands_no_hooks(self, temp_dir, valid_manifest_data):
+        """Test manifest with no commands and no hooks provided."""
        import yaml

        valid_manifest_data["provides"]["commands"] = []
+        valid_manifest_data.pop("hooks", None)

        manifest_path = temp_dir / "extension.yml"
        with open(manifest_path, 'w') as f:
            yaml.dump(valid_manifest_data, f)

-        with pytest.raises(ValidationError, match="must provide at least one command"):
+        with pytest.raises(ValidationError, match="must provide at least one command or hook"):
+            ExtensionManifest(manifest_path)
+
+    def test_hooks_only_extension(self, temp_dir, valid_manifest_data):
+        """Test manifest with hooks but no commands is valid."""
+        import yaml
+
+        valid_manifest_data["provides"]["commands"] = []
+        valid_manifest_data["hooks"] = {
+            "after_specify": {
+                "command": "speckit.test-ext.notify",
+                "optional": True,
+                "prompt": "Run notification?",
+            }
+        }
+
+        manifest_path = temp_dir / "extension.yml"
+        with open(manifest_path, 'w') as f:
+            yaml.dump(valid_manifest_data, f)
+
+        manifest = ExtensionManifest(manifest_path)
+        assert manifest.id == valid_manifest_data["extension"]["id"]
+        assert len(manifest.commands) == 0
+        assert len(manifest.hooks) == 1
+
+    def test_commands_null_rejected(self, temp_dir, valid_manifest_data):
+        """Test manifest with commands: null is rejected."""
+        import yaml
+
+        valid_manifest_data["provides"]["commands"] = None
+
+        manifest_path = temp_dir / "extension.yml"
+        with open(manifest_path, 'w') as f:
+            yaml.dump(valid_manifest_data, f)
+
+        with pytest.raises(ValidationError, match="Invalid provides.commands"):
+            ExtensionManifest(manifest_path)
+
+    def test_hooks_not_dict_rejected(self, temp_dir, valid_manifest_data):
+        """Test manifest with hooks as a list is rejected."""
+        import yaml
+
+        valid_manifest_data["hooks"] = ["not", "a", "dict"]
+
+        manifest_path = temp_dir / "extension.yml"
+        with open(manifest_path, 'w') as f:
+            yaml.dump(valid_manifest_data, f)
+
+        with pytest.raises(ValidationError, match="Invalid hooks"):
            ExtensionManifest(manifest_path)

    def test_manifest_hash(self, extension_dir):