git-third-party

Vendor third-party git content into your repo as ordinary files — no submodules.

Three surfaces, one Go core: a git-third-party CLI, Python bindings (import git_third_party), and Node bindings (import { add, list, ... } from 'git-third-party'). All three speak the same third-party.toml / third-party.lock config and share the same cgo bridge for in-process calls.

third-party.toml records each entry's source URL, the ref it tracks, and any filters applied. third-party.lock pins the resolved commits. git-third-party update re-fetches upstream and stages the changes.

Why

Submodules need a second clone, complicate CI, and hide third-party code from grep, build, and IDE tooling. Subtree merges lose provenance. git-third-party keeps content in-tree and visible to every tool, with enough metadata to update in one command.

Requirements

• git
• Go 1.21+ (build only)

Install

CLI

Prebuilt binaries cover linux-x64, linux-arm64, darwin-x64, darwin-arm64, and win32-x64. Pick whichever package manager you already have:

# PyPI (wheel ships the binary as a pip script):
uv tool install git-third-party
pip install --user git-third-party

# npm (main package shells out to the platform-specific binary):
npm install -g git-third-party
pnpm add -g git-third-party

Build from source:

go build -o ~/.local/bin/git-third-party .

The binary's git- prefix lets you invoke it as either git-third-party or git third-party.

Python bindings

uv tool install git-third-party    # or pip install

from git_third_party import init, add, list_, version

print(version())
init()
add(dir="vendor/foo", url="https://github.com/x/y", follow="main")
for e in list_():
    print(e.dir, e.commit)

Mutating calls take dry_run= and commit_msg=. All calls take repo_path= (default .). Errors map to GitThirdPartyError and its subclasses (ConfigError, NetworkError, ConflictError, CheckDirtyError).

Node bindings

npm install git-third-party     # or pnpm/yarn add

import { init, add, list, version } from "git-third-party";

console.log(version());
init();
add({ dir: "vendor/foo", url: "https://github.com/x/y", follow: "main" });
for (const e of list()) {
  console.log(e.dir, e.commit);
}

ECMAScript Modules (ESM) only, ships TypeScript types, requires Node ≥ 18. Same options shape as the Python API; same error hierarchy. The bridge serializes calls process-wide — for parallel work, use worker_threads.

Quick start

Vendor a directory tracking a remote branch:

git-third-party add third_party/zlib https://github.com/madler/zlib --follow master
git commit -m "Vendor zlib"

Pull updates:

git-third-party update                    # all entries
git-third-party update third_party/zlib   # one entry
git-third-party status                    # dry-run
git commit -m "Update vendored zlib"

List, rename, remove:

git-third-party list
git-third-party rename third_party/zlib vendor/zlib
git-third-party remove third_party/zlib

Tracking a ref

Each entry tracks exactly one of:

• --follow <branch> — track the branch tip, re-resolving on every update. Default when neither flag is set (resolved from the remote's HEAD).
• --pin <tag-or-sha> — pin to a tag (resolved once, then cached) or a commit SHA (used as-is). 40-hex-char strings count as SHAs.

Switch with git-third-party set <dir> --pin v1.3.1 (or --follow master).

Filtering content

Vendor part of an upstream repo:

git-third-party add vendor/foo https://example.com/foo.git \
    --subdir src \
    --include '*.c' --include '*.h' \
    --exclude 'tests/'

• --subdir — start from a subdirectory of the upstream repo.
• --include — keep only matching paths (repeatable; default keeps everything).
• --exclude — drop matching paths (repeatable; always wins over --include).

Patterns follow gitignore rules with documented deviations; see git-third-party add --help for the spec. Upstream submodules inline recursively unless excluded.

Configuration files

Two files live at the repo root, both committed:

• third-party.toml — hand-editable intent. Each [[third_party]] table is one vendored directory. Each add/set/rename/remove rewrites the file, dropping any user comments.
• third-party.lock — generated. Records the resolved commit and any saved tree-patch per entry. Sorted by dir for stable diffs. Do not edit by hand.

Example third-party.toml:

# git-third-party — vendored content config.

[[third_party]]
dir = "third_party/zlib"
url = "https://github.com/madler/zlib"
follow = "master"

[[third_party]]
dir = "vendor/foo"
url = "https://example.com/foo.git"
pin = "v1.3.1"
subdir = "src"
include = ["*.c", "*.h"]
exclude = ["tests/"]

Corresponding third-party.lock:

# git-third-party lockfile — generated; do not edit by hand.
version = 1

[[third_party]]
dir = "third_party/zlib"
commit = "abc123..."

[[third_party]]
dir = "vendor/foo"
commit = "def456..."

Commands

Command	Aliases	Purpose
init		Create an empty third-party.toml (most users skip this — add creates it).
add DIR URL		Register a new entry and download it.
set DIR …	edit	Change URL, ref, or filters for an existing entry.
unset DIR FIELD…		Clear subdir, include, or exclude.
update [DIR]	up	Re-fetch and stage updates.
status [DIR]	st	update --dry-run.
list [DIR]	ls	Show entries and their tracking mode.
info DIR	show	Print full details for one entry.
rename DIR NEW_DIR	mv	Move a vendored directory and update the config.
remove DIR	rm	Unregister a directory and git rm -r its content.
patch save DIR		(experimental) Record local edits as a tree-patch.
patch diff DIR		(experimental) Show the saved tree-patch via git diff.
completion SHELL		Print a bash/zsh/fish/powershell completion script.

Common flags

• -v, -vv, -q — debug, trace, or warn-only logging.
• --log-level=trace|debug|info|warn|error — explicit level.
• --log-format=text|json — switch the stderr handler to JSON.
• --color=auto|always|never — honors NO_COLOR.
• --dry-run — plan without staging.
• -f, --allow-dir-exists — let add/rename write into a non-empty target.
• --profile <path> — write a CPU profile.
• --json — emit a structured entryResult (or array) on stdout instead of human text. Schema lives in output.go.
• --commit MSG — run git commit -m MSG after the command stages changes.
• --check (on update/status) — exit non-zero if any entry would change. Useful in CI and pre-commit hooks.

Exit codes

Code	Meaning
0	success
1	generic failure
2	configuration invalid (TOML parse, validation, lockfile schema mismatch)
3	network, fetch, or ref-resolution failure
4	unresolvable merge conflict during update
5	--check detected a pending change

Settings

Settings resolve through five layers, each overriding the previous:

1. Built-in defaults.
2. Per-user: git config --global third-party.<key>.
3. Per-repo: a [settings] table in third-party.toml.
4. Environment variables.
5. CLI flags.

Environment variables:

• GIT_THIRD_PARTY_LOG_LEVEL (trace/debug/info/warn/error) — same as --log-level.
• GIT_THIRD_PARTY_LOG_FORMAT (text/json) — same as --log-format.
• GIT_THIRD_PARTY_COLOR (auto/always/never) — same as --color.
• GIT_THIRD_PARTY_EXPERIMENTAL — comma-separated feature names; same as --experimental.
• NO_COLOR — standard cross-tool convention; disables ANSI color even when --color=auto.

Experimental commands (currently the patch subtree) need explicit opt-in: --experimental=patch (-Z patch), experimental = ["patch"] under [settings], or git config --global third-party.experimental patch.

Shell completions

# bash
source <(git-third-party completion bash)

# zsh
git-third-party completion zsh > "${fpath[1]}/_git-third-party"

# fish
git-third-party completion fish > ~/.config/fish/completions/git-third-party.fish

Editing vendored content (experimental)

Enable with --experimental=patch (or set the equivalent in [settings] or git-config — see Settings):

• git-third-party --experimental=patch patch save <dir> — record local modifications as a tree-level patch in third-party.lock. The patch reapplies on every update via a 3-way merge.
• git-third-party --experimental=patch patch diff <dir> — show the saved patch.

If update produces conflicts, git-third-party stores the patch with a -conflicts suffix; resolve with git add followed by another patch save. Review the resulting commits carefully — the feature is experimental for a reason.

License

MIT — see LICENSE.