feat: make git extension opt-in and remove --no-git at v0.10.0 (#2873)

* feat(init)!: make git extension opt-in and remove --no-git at v0.10.0

- Remove --no-git parameter from specify init command
- Remove git extension auto-installation from init flow
- Git repository initialization (git init) still runs when git is available
- Remove --no-git from all test invocations across the test suite
- Update docs to reflect opt-in git extension behavior
- Replace TestGitExtensionAutoInstall with TestGitExtensionOptIn tests

BREAKING CHANGE: specify init no longer auto-installs the git extension.
Use `specify extension add git` to install it explicitly.
The --no-git flag has been removed.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* refactor(scripts): remove git operations from core scripts

Git functionality is now entirely managed by the git extension.
Core scripts only handle directory-based feature creation and numbering.

- Remove has_git(), check_feature_branch(), git branch creation from core
- Simplify number detection to use only spec directory scanning
- Remove HAS_GIT output from get_feature_paths()
- Remove git remote fetching and branch querying
- Keep BRANCH_NAME output key for backward compatibility

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* refactor: remove all git operations from core

- Remove is_git_repo() and init_git_repo() dead code from _utils.py
- Remove --branch-numbering from init command
- Remove git from 'specify check' (now extension-only)
- Update docs: git is optional prerequisite, check command description
- Fix tests to reflect no-git-in-core reality (fallback to main)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* refactor(scripts): remove directory scanning and branch fallback from core

Core scripts now resolve feature context exclusively from:
1. SPECIFY_FEATURE env var (set by git extension)
2. .specify/feature.json (persisted by specify command)

Removed find_feature_dir_by_prefix() and directory scanning heuristics —
these are the git extension's responsibility. Scripts error clearly when
no feature context is available.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* feat: introduce feature_numbering, deprecate branch_numbering in init-options

- specify command template now reads feature_numbering (preferred) with
  fallback to branch_numbering (deprecated) from init-options.json
- Git extension reads git-config.yml > feature_numbering > branch_numbering
- init now writes feature_numbering: sequential to init-options.json
- Deprecation warning emitted when branch_numbering is used as fallback

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix: remove trailing whitespace in common.ps1

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* feat(scripts): persist SPECIFY_FEATURE_DIRECTORY env var to feature.json

When SPECIFY_FEATURE_DIRECTORY is set, get_feature_paths() now writes the
value to .specify/feature.json so future sessions without the env var can
still resolve the feature directory. The write is idempotent — it skips
when the file already contains the same value.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix: address review feedback — error messages and docs

- Update error messages in common.sh and common.ps1 to reference
  SPECIFY_FEATURE_DIRECTORY instead of SPECIFY_FEATURE (which no longer
  resolves feature directories)
- Fix get_current_branch comment (returns empty string, not error)
- Update upgrade.md to reference SPECIFY_FEATURE_DIRECTORY with correct
  example paths
- Update local-development.md troubleshooting: replace stale 'Git step
  skipped' row with actionable git extension guidance

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix(scripts): harden feature.json persistence

- Use json_escape in printf fallback when jq is unavailable (common.sh)
- Replace utf8NoBOM encoding with UTF8Encoding($false) for PowerShell
  5.1 compatibility (common.ps1)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* refactor(scripts): remove dead feature_json_matches_feature_dir functions

These guards are no longer needed since the branch-name validation they
protected against has been removed from check-prerequisites.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* refactor(git-ext): rename create-new-feature to create-new-feature-branch

The git extension's script only creates the git branch — rename it to
reflect that responsibility. The core create-new-feature.sh/.ps1 handles
feature directory creation and feature.json persistence.

Also includes fixes from review feedback:
- common.sh: _persist_feature_json uses json_escape fallback
- common.ps1: Save-FeatureJson uses UTF8Encoding for PS 5.1 compat
- common.ps1: case-sensitive path stripping on non-Windows
- create-new-feature.sh/ps1: output both SPECIFY_FEATURE and
  SPECIFY_FEATURE_DIRECTORY
- setup-tasks.sh: fix stale 'Validate branch' comment

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix(tests): update references to renamed git extension scripts

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix(tests): remove duplicate EXT_CREATE_FEATURE assignments

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Manfred Riem <mnriem@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: 3 people

docs/installation.md

@@ -6,7 +6,7 @@
 - AI coding agent: [Claude Code](https://www.anthropic.com/claude-code), [GitHub Copilot](https://code.visualstudio.com/), [Codebuddy CLI](https://www.codebuddy.ai/cli), [Gemini CLI](https://github.com/google-gemini/gemini-cli), or [Pi Coding Agent](https://pi.dev)
 - [uv](https://docs.astral.sh/uv/) for package management (recommended) or [pipx](https://pipx.pypa.io/) for persistent installation
 - [Python 3.11+](https://www.python.org/downloads/)
-- [Git](https://git-scm.com/downloads)
+- [Git](https://git-scm.com/downloads) _(optional — required only when the git extension is enabled)_
 
 ## Installation
 

docs/local-development.md

@@ -162,7 +162,7 @@ rm -rf .venv dist build *.egg-info
 |---------|-----|
 | `ModuleNotFoundError: typer` | Run `uv pip install -e .` |
 | Scripts not executable (Linux) | Re-run init or `chmod +x scripts/*.sh` |
-| Git step skipped | You passed `--no-git` or Git not installed |
+| Git commands unavailable | Install the git extension with `specify extension add git` |
 | Wrong script type downloaded | Pass `--script sh` or `--script ps` explicitly |
 | TLS errors on corporate network | Configure your environment's certificate store or proxy. The `--skip-tls` flag is deprecated and has no effect. |
 

docs/reference/core.md

@@ -15,16 +15,13 @@ specify init [<project_name>]
 | `--script sh\|ps`        | Script type: `sh` (bash/zsh) or `ps` (PowerShell)                       |
 | `--here`                 | Initialize in the current directory instead of creating a new one        |
 | `--force`                | Force merge/overwrite when initializing in an existing directory         |
-| `--no-git`               | Skip git repository initialization                                       |
 | `--ignore-agent-tools`   | Skip checks for AI coding agent CLI tools                                |
 | `--preset <id>`          | Install a preset during initialization                                   |
-| `--branch-numbering`     | Branch numbering strategy: `sequential` (default) or `timestamp`         |
 
 Creates a new Spec Kit project with the necessary directory structure, templates, scripts, and AI coding agent integration files.
 
 > [!NOTE]
-> The git extension is currently enabled by default during `specify init`.
-> Starting in `v0.10.0`, it will require explicit opt-in. To add it after init, run `specify extension add git`.
+> Git repository initialization and branching are managed by the **git extension**, which is not installed by default. Run `specify extension add git` after init to enable git workflows.
 
 Use `<project_name>` to create a new directory, or `--here` (or `.`) to initialize in the current directory. If the directory already has files, use `--force` to merge without confirmation.
 
@@ -45,14 +42,8 @@ specify init --here --force --integration copilot
 # Use PowerShell scripts (Windows/cross-platform)
 specify init my-project --integration copilot --script ps
 
-# Skip git initialization
-specify init my-project --integration copilot --no-git
-
 # Install a preset during initialization
 specify init my-project --integration copilot --preset compliance
-
-# Use timestamp-based branch numbering (useful for distributed teams)
-specify init my-project --integration copilot --branch-numbering timestamp
 ```
 
 ### Environment Variables
@@ -67,7 +58,7 @@ specify init my-project --integration copilot --branch-numbering timestamp
 specify check
 ```
 
-Checks that required tools are available on your system: `git` and any CLI-based AI coding agents. IDE-based agents are skipped since they don't require a CLI tool.
+Checks that CLI-based AI coding agents are available on your system. IDE-based agents are skipped since they don't require a CLI tool.
 
 This command stays offline. If a command behaves like an older Spec Kit version or an expected CLI feature is missing, run `specify self check` to check whether your local CLI is behind the latest release.
 

docs/upgrade.md

@@ -257,70 +257,38 @@ rm speckit.old-command-name.md
 # Restart your IDE
 ```
 
-### Scenario 4: "I'm working on a project without Git"
+### Scenario 4: "I don't want the git extension"
 
-If you initialized your project with `--no-git`, you can still upgrade:
+The git extension is now opt-in, so upgrades do not install it unless you add it explicitly.
 
 ```bash
 # Manually back up files you customized
-cp .specify/memory/constitution.md /tmp/constitution-backup.md
+cp .specify/memory/constitution.md .specify/memory/constitution.backup.md
 
 # Run upgrade
-specify init --here --force --integration copilot --no-git
+specify init --here --force --integration copilot
 
 # Restore customizations
-mv /tmp/constitution-backup.md .specify/memory/constitution.md
+mv .specify/memory/constitution.backup.md .specify/memory/constitution.md
 ```
 
-The `--no-git` flag skips git initialization but doesn't affect file updates.
-
----
-
-## Using `--no-git` Flag
-
-The `--no-git` flag tells Spec Kit to **skip git repository initialization**. This is useful when:
-
-- You manage version control differently (Mercurial, SVN, etc.)
-- Your project is part of a larger monorepo with existing git setup
-- You're experimenting and don't want version control yet
-
-**During initial setup:**
+If you later decide you want the git extension's commands and hooks, install it explicitly:
 
 ```bash
-specify init my-project --integration copilot --no-git
+specify extension add git
 ```
 
-**During upgrade:**
-
-```bash
-specify init --here --force --integration copilot --no-git
-```
-
-### What `--no-git` does NOT do
-
-❌ Does NOT prevent file updates
-❌ Does NOT skip slash command installation
-❌ Does NOT affect template merging
-
-It **only** skips running `git init` and creating the initial commit.
-
-### Working without Git
-
-If you use `--no-git`, you'll need to manage feature directories manually:
-
-**Set the `SPECIFY_FEATURE` environment variable** before using planning commands:
+Projects that do not use Git can still work with Spec Kit by setting `SPECIFY_FEATURE_DIRECTORY` to the feature directory path before planning commands:
 
 ```bash
 # Bash/Zsh
-export SPECIFY_FEATURE="001-my-feature"
+export SPECIFY_FEATURE_DIRECTORY="specs/001-my-feature"
 
 # PowerShell
-$env:SPECIFY_FEATURE = "001-my-feature"
+$env:SPECIFY_FEATURE_DIRECTORY = "specs/001-my-feature"
 ```
 
-This tells Spec Kit which feature directory to use when creating specs, plans, and tasks.
-
-**Why this matters:** Without git, Spec Kit can't detect your current branch name to determine the active feature. The environment variable provides that context manually.
+Alternatively, run the `/speckit.specify` command which creates `.specify/feature.json` automatically.
 
 ---
 

extensions/git/README.md

@@ -94,7 +94,7 @@ When Git is not installed or the directory is not a Git repository:
 
 The extension bundles cross-platform scripts:
 
-- `scripts/bash/create-new-feature.sh` — Bash implementation
+- `scripts/bash/create-new-feature-branch.sh` — Bash implementation (branch creation only)
 - `scripts/bash/git-common.sh` — Shared Git utilities (Bash)
-- `scripts/powershell/create-new-feature.ps1` — PowerShell implementation
+- `scripts/powershell/create-new-feature-branch.ps1` — PowerShell implementation (branch creation only)
 - `scripts/powershell/git-common.ps1` — Shared Git utilities (PowerShell)

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

@@ -31,8 +31,9 @@ If the user explicitly provided `GIT_BRANCH_NAME` (e.g., via environment variabl
 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
+2. Check `.specify/init-options.json` for `feature_numbering` value (inherit from core)
+3. Check `.specify/init-options.json` for `branch_numbering` value (deprecated, backward compatibility — will be removed in a future release)
+4. Default to `sequential` if none of the above exist
 
 ## Execution
 
@@ -43,10 +44,10 @@ Generate a concise short name (2-4 words) for the branch:
 
 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>"`
+- **Bash**: `.specify/extensions/git/scripts/bash/create-new-feature-branch.sh --json --short-name "<short-name>" "<feature description>"`
+- **Bash (timestamp)**: `.specify/extensions/git/scripts/bash/create-new-feature-branch.sh --json --timestamp --short-name "<short-name>" "<feature description>"`
+- **PowerShell**: `.specify/extensions/git/scripts/powershell/create-new-feature-branch.ps1 -Json -ShortName "<short-name>" "<feature description>"`
+- **PowerShell (timestamp)**: `.specify/extensions/git/scripts/powershell/create-new-feature-branch.ps1 -Json -Timestamp -ShortName "<short-name>" "<feature description>"`
 
 **IMPORTANT**:
 - Do NOT pass `--number` — the script determines the correct next number automatically

…s/git/scripts/bash/create-new-feature.sh …cripts/bash/create-new-feature-branch.shextensions/git/scripts/bash/create-new-feature.sh renamed to extensions/git/scripts/bash/create-new-feature-branch.sh extensions/git/scripts/bash/create-new-feature.sh renamed to extensions/git/scripts/bash/create-new-feature-branch.sh

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
-# Git extension: create-new-feature.sh
-# Adapted from core scripts/bash/create-new-feature.sh for extension layout.
+# Git extension: create-new-feature-branch.sh
+# Creates a git feature branch only. The feature directory and spec file
+# are created by the core create-new-feature.sh script.
 # Sources common.sh from the project's installed scripts, falling back to
 # git-common.sh for minimal git helpers.
 

…cripts/powershell/create-new-feature.ps1 …powershell/create-new-feature-branch.ps1extensions/git/scripts/powershell/create-new-feature.ps1 renamed to extensions/git/scripts/powershell/create-new-feature-branch.ps1 extensions/git/scripts/powershell/create-new-feature.ps1 renamed to extensions/git/scripts/powershell/create-new-feature-branch.ps1

@@ -1,6 +1,7 @@
 #!/usr/bin/env pwsh
-# Git extension: create-new-feature.ps1
-# Adapted from core scripts/powershell/create-new-feature.ps1 for extension layout.
+# Git extension: create-new-feature-branch.ps1
+# Creates a git feature branch only. The feature directory and spec file
+# are created by the core create-new-feature.ps1 script.
 # Sources common.ps1 from the project's installed scripts, falling back to
 # git-common.ps1 for minimal git helpers.
 [CmdletBinding()]
@@ -19,7 +20,7 @@ param(
 $ErrorActionPreference = 'Stop'
 
 if ($Help) {
-    Write-Host "Usage: ./create-new-feature.ps1 [-Json] [-DryRun] [-AllowExistingBranch] [-ShortName <name>] [-Number N] [-Timestamp] <feature description>"
+    Write-Host "Usage: ./create-new-feature-branch.ps1 [-Json] [-DryRun] [-AllowExistingBranch] [-ShortName <name>] [-Number N] [-Timestamp] <feature description>"
     Write-Host ""
     Write-Host "Options:"
     Write-Host "  -Json               Output in JSON format"
@@ -37,7 +38,7 @@ if ($Help) {
 }
 
 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>"
+    Write-Error "Usage: ./create-new-feature-branch.ps1 [-Json] [-DryRun] [-AllowExistingBranch] [-ShortName <name>] [-Number N] [-Timestamp] <feature description>"
     exit 1
 }
 

scripts/bash/check-prerequisites.sh

@@ -111,9 +111,6 @@ if $PATHS_ONLY; then
     exit 0
 fi
 
-# Validate branch name
-check_feature_branch "$CURRENT_BRANCH" "$HAS_GIT" || exit 1
-
 # Validate required directories and files
 if [[ ! -d "$FEATURE_DIR" ]]; then
     echo "ERROR: Feature directory not found: $FEATURE_DIR" >&2