Git A2a README | AllMCPs

git-a2a

Import a Git repository together with the agents that own it.

git-a2a is an open standard plus a static Go CLI for micro-agent architectures. A repository publishes one a2amodule.yml: what the module exports, which agents own it, how to contact them, and which other modules it consumes. The CLI resolves one Git commit, wires every detected ecosystem, maintains a2amodule.lock, and projects the useful ownership context into agent tools.

Read the human specification, the command reference, or the normative spec/_.hint with hint spec.

See the feature end to end in the public acme-lib-utils library and consumer-app consumer repositories. The demo walkthrough explains what to inspect and which commands to run.

What you can do

Capability	Commands and result
Dependency wiring	`add`, `wire`, `update`, `remove` edit native npm/Python/Go/Rust/Swift/Dart/Ruby/PHP/Elixir/Haskell/Zig/Clojure/Nix files at one resolved commit.
Source changes	`set`, `pin`, and `unpin` transactionally change URL, ref, monorepo path, tracking, or identity.
Owners and contacts	`who` routes an intent and path to the declared role, scoped agent, and ordered contacts.
Agent roster	`sync` maintains a bounded dependency/owner block in `AGENTS.md` or another target.
Contact delivery	`contact` sends through A2A, email, or GitHub/GitLab/Gitea-family issues; any tracker can use exact instructions or a consumer plugin.
Vendoring and build systems	`--vendor submodule` or `--vendor copy` plus CMake/Gradle/MSBuild/Maven/Meson generated includes keep source at the lock commit.
Fresh-checkout restore	`fetch` reconstructs cache and vendored trees from the lock without resolving a new commit.
Cards, catalog, and trust	`card`, `catalog`, and `trust show` verify A2A cards, key/origin pins, signed commits, and ARD catalogs.
Liveness and drift	`status` compares upstream refs, manifest/cache hashes, native wiring, cards, trust, and synced context.
Agent UX	`usage`, the portable skill, `setup`, and `explain` brief and configure supported agent harnesses.
MCP	`mcp` exposes the same commands over bounded multi-repository stdio tools; write access is opt-in.
Prerequisites	`doctor` reports Git and native ecosystem tools with versions and install hints; it never installs them.

Quick start

git-a2a init --id acme-app
git-a2a add https://github.com/acme/lib-utils.git
git-a2a sync
git-a2a who acme-lib-utils --intent change
git-a2a status
git-a2a update --review

Owners start with git-a2a init --example lib, add an agent with git-a2a agent add, then run git-a2a validate and git-a2a card export.

Vendored dependencies

A consumer can materialize a locked dependency inside its repository with add --vendor submodule or add --vendor copy; set --vendor changes that choice later. The lock still names one Git commit for every ecosystem, while native npm, Cargo, Go, Pub, Mix, uv, and Composer wiring and generated CMake, Gradle, MSBuild, Maven, or Meson integrations resolve through the vendored directory. git-a2a fetch restores missing cache and vendored content from the lock in a fresh checkout without resolving a new commit. See the consumer workflow and the live consumer-app submodule example.

Works with

Layer	Integrations and wiring
Native ecosystems	npm, uv/PyPI, Go, Cargo, SwiftPM, Pub, Bundler, Composer, Mix, Cabal/Stack, Zig, Clojure, Nix — native Git forms, or local path forms when vendored.
Build systems	CMake, Gradle, Maven, MSBuild, Meson — one generated include/import for vendored source.
Agent harnesses	Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode, Hermes Agent, OpenClaw — skill and repository-scoped MCP setup.
Distribution channels	Go, Go zero-install, macOS/Linux installer, Windows installer, Homebrew, Scoop, npm, PyPI with uv, PyPI with pipx, Container, Nix flake — one release binary, verified through channel-native entry points.
Contact kinds	a2a, github-issue, gitlab-issue, gitea-issue, bitbucket-issue, azure-boards, http, exec, email, jira, mattermost, slack, discord, telegram, teams, url — built-in delivery, consent-gated invocation, plugin, or exact instruction.
Standards	A2A, AGENTS.md, Agent Skills, ARD catalogs, MCP, MCP Registry — native projections; MCP Registry listing.

The reference CLI implements a2amodule schema 1 and passes conformance version 1 on Linux and Windows.

Installation

Go-native channels are the simplest and come first. Every checkmark means the channel was exercised against a public stable artifact on its native platform. These commands follow the latest stable release; pin an explicit version in CI.

Verified	Channel	Command
✔	Go	`go install github.com/neprel/git-a2a/cmd/git-a2a@latest`
✔	Go zero-install	`go run github.com/neprel/git-a2a/cmd/git-a2a@latest --version`
✔	macOS/Linux installer	`curl -fsSL https://git-a2a.com/install.sh \| bash`
✔	Windows installer	`irm https://git-a2a.com/install.ps1 \| iex`
✔	Homebrew	`brew install neprel/tap/git-a2a`
✔	Scoop	`scoop bucket add git-a2a https://github.com/neprel/scoop-bucket; scoop install git-a2a`
✔	npm	`npx git-a2a@latest --version`
✔	PyPI with uv	`uvx git-a2a --version`
✔	PyPI with pipx	`pipx run git-a2a --version`
✔	Container	`docker run --pull=always --rm ghcr.io/neprel/git-a2a:latest --version`
✔	Nix flake	`nix run github:neprel/git-a2a -- version`

The checksum-verifying standalone installers support GIT_A2A_VERSION, --version, --dir, and --dry-run. The macOS binaries are not yet Apple-notarized; use the Homebrew formula for a checksum-verified first launch without a Gatekeeper quarantine prompt.

Linux .deb, .rpm, and .apk packages are attached to every GitHub Release:

sudo dpkg -i git-a2a_*.deb
sudo rpm -i git-a2a_*.rpm
sudo apk add --allow-untrusted git-a2a_*.apk

The scratch container contains only the binary:

Terminal

docker run --pull=always --rm ghcr.io/neprel/git-a2a:latest version

Every channel executes the same Go binary. git-a2a version --check is the only automatic release lookup and prints the correct manager-specific update command. git-a2a upgrade is available only to the standalone binary channel; it never overwrites a package-manager install. Release archives cover Darwin, Linux, and Windows on amd64/arm64 and include checksums and SBOMs. Maintainer setup is in docs/releasing.md.

Verify a download

Every tag-triggered release asset has GitHub build provenance bound to this repository's pinned release workflow. After downloading an asset with gh release download, verify that identity:

gh attestation verify PATH/TO/ASSET \
  --repo neprel/git-a2a \
  --signer-workflow neprel/git-a2a/.github/workflows/release.yml
sha256sum --ignore-missing -c checksums.txt

The GHCR image is signed keylessly at its immutable digest. Resolve the digest for the version you intend to run, then require GitHub's OIDC issuer and the tag-triggered release workflow:

cosign verify \
  --certificate-identity-regexp '^https://github\.com/neprel/git-a2a/\.github/workflows/release\.yml@refs/tags/v[0-9]+\.[0-9]+\.[0-9]+(-rc\.[0-9]+)?$' \
  --certificate-oidc-issuer https://token.actions.githubusercontent.com \
  ghcr.io/neprel/git-a2a@sha256:DIGEST

Documentation

Manifest field reference: generated types, defaults, values, and consequences for every field.
Authoring guide: create and publish a module, its surface, agents, contacts, policy, and cards.
Consumer guide: add, fetch, sync, inspect, update, contact, and run deterministic CI.
Vendoring guide: submodule/copy tradeoffs, build systems, path mode, rollback, and CI.
Trust guide: pinned cards, signed commits, origins, rotation, and external delivery policy.
Release verification: provenance, container signatures, channels, and release gates.
Agent/operator guide: usage, skill installation, setup by harness, MCP roots, and machine-output safety.
Contact kinds: generated allowed fields and delivery/instruction behavior for every known kind.
Contact plugins: consumer-side JSON protocol for open contact kinds.
FAQ: design boundaries, offline operation, A2A, MCP, Agent Skills, and disposable cache.
Consumer demo: inspect the public polyglot library and app end to end.
CLI reference: exact commands, flags, outputs, and exit codes.
MCP server: attach the multi-repository stdio server to Claude Code, Codex, Cursor, Copilot, Gemini CLI, OpenCode, Hermes Agent, or OpenClaw.

How it relates

A2A is the agent-to-agent protocol. Agent Cards remain native A2A v1.0; the https://git-a2a.com/ext/module/v1 extension binds a card to a Git module without copying its self-description. contact can deliver A2A SendMessage requests.
AGENTS.md is a consumer-facing context surface. sync renders only published module, surface, ownership, and routing data into a managed block; it never imports dependency instructions or private implementation knowledge.
Agent Skills teach a harness how to perform a task. They complement git-a2a: a Skill may call this CLI, while a2amodule.yml remains the durable, harness-neutral ownership and dependency contract shared by every agent environment. Install this repository's skill with npx skills add neprel/git-a2a or, before the 1.1.0 tag, gh skill install neprel/git-a2a git-a2a --pin main. From 1.1.0 onward the stable command is gh skill install neprel/git-a2a git-a2a; detailed references ship with the skill and in the npm launcher package. Run git-a2a setup --dry-run to preview repository-scoped skill, AGENTS.md, and MCP configuration for detected Claude Code, Codex, Cursor, Copilot, Gemini CLI, OpenCode, Hermes Agent, and OpenClaw environments.
MCP is an optional stdio projection of the same CLI and files. It is not a daemon or an identity/package registry; declared roots bound which repositories tools may access.

git-a2a does not run agents, host endpoints, or choose a chat platform. Unknown contact kinds, roles, intents, and ecosystems remain valid open vocabulary.

Specification as source (HINT)

The repository's durable knowledge—decisions, invariants, and the normative standard in spec/_.hint—lives in .hint files beside the artifacts it governs; this is Spec-as-Source. hint <path> returns exactly the knowledge governing that path, hint spec prints the standard, and hint status checks for drift. HINT is an open, agent-neutral tool by the same author; install it with npm install -g @openhint/cli or run it with npx @openhint/cli. This repository's vocabulary comes from hintbook-software-engineer. Agents here run hint before editing; that requirement is the purpose of the <hint> block in AGENTS.md, while hint.yml selects the hintbook.

License: MIT.

Built with HINT.