git-agent

Commit, PR, release, review, simplification, and repository-search context for AI-assisted Git work.

git-agent gathers Git evidence with typed Go code, runs a bounded OpenAI-compatible tool-calling loop, and keeps model tools read-only. The commit command is the only workflow that writes to Git, and it does that after message generation by handing the final message to git commit.

TL;DR: use commit-msg when you want a grounded commit message on stdout, use commit when you want the same message created as a Git commit, use release-note for release Markdown, and use search when an agent needs fast local implementation context. Use review for evidence-backed defects and simplify for behavior-preserving cleanup opportunities.

Quick Start

# 1. Install the binary
go install github.com/yusing/git-agent/cmd/git-agent@latest

# 2. Generate a commit message from staged changes
git-agent commit-msg

# 3. Or generate and create the commit
git-agent commit

By default, message-generation commands use ChatGPT/Codex auth from ~/.codex/auth.json. OPENAI_API_KEY is the fallback for OpenAI-compatible provider auth when that file is absent.

go install writes to $(go env GOPATH)/bin by default; make sure that directory is on PATH.

Everyday Workflows

Workflow	Command	Output
Staged commit message	git-agent commit-msg	Final commit message on stdout
Amend commit message	git-agent commit-msg --amend	Final amended commit message on stdout
Generate and commit	git-agent commit	Human trace, then Git commit output
Generate and amend	git-agent commit --amend	Human trace, then Git amend output
Squash PR message	git-agent pr-message	Squash merge message on stdout
Release body	git-agent release-note <base> <release>	Release Markdown on stdout
Version bump release body	git-agent release-note patch	Release Markdown for latest tag to HEAD
Uncommitted review	git-agent review	Detached task launch JSON
Staged review	git-agent review --staged	Detached staged-review launch JSON
Codebase simplification audit	git-agent simplify --codebase	Detached codebase-audit launch JSON
Agent context search	git-agent search --agent <query...>	Brief results, plus progress endpoint when indexing
Configure index sync	git-agent config index.remote <git-url>	Save a dedicated Git remote for shared revision indexes
Push local indexes	git-agent index sync	Additively publish all completed local revision indexes
List search indexes	git-agent search --ls	Local index summaries for the current project
List indexed files	git-agent search --ls-files	Tree of files stored in the selected index

Why git-agent?

LLMs are useful for Git writing, but raw prompts miss repository facts easily: staged scope, amend intent, recent message style, generated-heavy diffs, submodule history, guidance files, release ranges, and stdout/stderr contracts.

git-agent front-loads those facts before the model writes:

1. It inspects the repository with typed Git plumbing.
2. It builds task-specific evidence for commit, PR, release, or search work.
3. It exposes only narrow read-only tools when the model needs more context.
4. It validates and shapes final output for the requested workflow.

For submodule-only staged updates, normal commit-msg and commit skip the LLM entirely and format a deterministic local message.

What It Provides

Surface	What it does
Prepared Git context	Staged paths, status, stats, diffs, amend base, branch diffs, release ranges, and recent style commits
Read-only model tools	Bounded file, diff, and repository inspection tools for generation workflows
Guidance discovery	AGENTS/CLAUDE-family project instructions, plus local Codex-style SKILL.md workflow guidance
Commit execution	Optional explicit git commit --file - or git commit --amend --file - after message generation
Release-note writing	Release Markdown from explicit refs or patch, minor, and major shortcuts
Review and simplification	Strict JSON reports with repository evidence and replayable SSE agent events
Embedding search	Local filesystem or committed-tree context search for agents and humans
Debug output	Human console diagnostics with --debug; pprof with --pprof <addr>

Review and Simplify

review and simplify are read-only Responses API workflows designed for LLM harnesses. Both default to all dirty changes, regardless of staging state.

# Review staged and unstaged work together
git-agent review
# {"command":"review","id":"...","pid":12345,"endpoint":{"network":"unix","address":"/tmp/.../http.sock","url":"http://localhost/events?token=..."}}
git-agent review --wait <id-from-launch-json>

# Review only the Git index
git-agent review --staged

# Audit the full repository
git-agent review --codebase

# Find behavior-preserving cleanup opportunities in dirty changes
git-agent simplify
git-agent simplify --wait <id-from-launch-json>

# Add lower-priority task focus after flags
git-agent review --staged focus on cancellation and cleanup

Exactly one mode may be selected: --codebase, --uncommitted, or --staged. No mode means --uncommitted. Both commands always launch detached and write one strict launch JSON object to stdout. It contains command, durable task id, producer pid, and authenticated event url. Successful launch writes nothing to stderr. Matching --wait <id> forms write strict, evidence-located JSON reports to stdout. They have no request deadline by default; --timeout <duration> adds one explicitly. Without --model or OPENAI_MODEL, review uses gpt-5.6-sol and simplify uses gpt-5.6-terra; both use provider-default reasoning effort unless an effort flag is supplied.

Diff-mode prompts include a bounded context-pack view and bounded unified diff; full changed-path scope remains available to validation and read-only repository tools without duplicating every path, status, and stat in the initial request. The model can page through that complete inventory before requesting narrow path-specific diffs. Requests whose initial serialized estimate reaches the configured context budget fail before contacting the provider.

Both commands offer provider-hosted web search on every normal model step using the existing OpenAI API-key or ChatGPT/Codex-plan login. API-key auth caps hosted searches at four per response by default; plan auth leaves provider default uncapped. --max-web-searches <n> overrides either default. No search-specific credential is needed. A provider that rejects hosted search is retried once without it, and report summary discloses lookup limitation. Wire behavior follows the OpenAI web-search guide.

Installed go, rustup, and ctx7 executables add typed go_doc, rust_doc, context7_library, and context7_docs tools. Missing commands are simply omitted. These tools run fixed documentation-only argument shapes without shell access or auto-installation. Context7 works logged out at lower service limits, as described by its CLI documentation. External queries must contain only public language/library questions—never secrets, source, diffs, credentials, personal data, or private repository details. Reports retain exact repository evidence and list up to five material external source URLs or local documentation locators in summary.

The launch object's replayable local endpoint includes live reasoning-summary progress:

{"command":"review","id":"4YH2S7M6N5QK8J3C9RTPABCD","pid":12345,"endpoint":{"network":"unix","address":"/tmp/git-agent-.../http.sock","url":"http://localhost/events?token=..."}}

The detached review or simplification process continues serving events through the terminal event. review --wait <id> or simplify --wait <id> waits without a deadline and prints only the strict final report JSON. Completed reports can be retrieved repeatedly. Failed, unknown, malformed, corrupt, dead-producer, or wrong-command tasks fail with empty stdout; signals cancel an active wait. Invalid tool arguments and missing evidence paths are returned to the model as structured errors so it can correct the request instead of aborting the task.

See docs/spec.md for exact mode, schema, tool, and SSE contracts.

codex-herdr integration

git-agent works with codex-herdr to show live review and simplification progress in a Herdr activity pane. From a managed root Codex session, run:

git-agent review --uncommitted

The command returns launch JSON while codex-herdr follows the review. Its pid identifies the detached process when manual termination is needed.

Git Agent does not require codex-herdr; both commands still work normally on their own.

Search

git-agent search is embedding-backed implementation-location search. It does not run the Responses API.

# Search current filesystem files; Git repositories share a root index
git-agent search "where is release note evidence prepared"

# Compact output for humans
git-agent search --format brief "where are search flags parsed"

# Agent mode: compact output plus progress probe when indexing
git-agent search --agent "where are search flags parsed"

# Search code only, excluding common tests
git-agent search --code --no-tests "commit amend validation"

# Index first, without running a query
git-agent search --index

# Search a committed tree instead of the working filesystem
git-agent search --rev HEAD~1 "guidance discovery"

# Search a cached remote repository
git-agent search --remote https://github.com/yusing/git-agent.git "search flags"

# List search indexes for this project
git-agent search --ls

# List cached remote repositories
git-agent search --ls-remotes

# List indexed files as a tree
git-agent search --ls-files

Search reads OPENAI_EMBEDDING_API_KEY first, then falls back to OPENAI_API_KEY. Codex/ChatGPT auth is not used for embeddings. Use OPENAI_EMBEDDING_BASE_URL, OPENAI_EMBEDDING_MODEL, and OPENAI_EMBEDDING_DIMENSIONS to isolate search embedding config from normal message-generation config.

Search indexes can be synchronized through a dedicated Git repository:

git-agent config index.remote git@example.com:team/git-agent-indexes.git
git-agent config index.remote
git-agent index sync
git-agent config --unset index.remote

Normal search syncs selected revision: committed HEAD for filesystem search, resolved --rev, or selected --remote revision. Working-tree-only vectors remain local. git-agent index sync additively publishes every completed local revision index without embedding new content. Index repository must be dedicated to git-agent; unreachable remote fails explicitly. Sync progress is reported on stderr in terminals and redirected output, including bracketed fetch/push object-transfer progress, while final summary remains on stdout. See docs/spec.md for exact sync contracts.

Generated index-store commits are always unsigned. This is enforced only in the dedicated local index-sync repository and does not change signing settings for source repositories or search --remote caches.

SSH remotes try available agent identities first, then unencrypted default keys in ~/.ssh/id_ed25519, id_ecdsa, id_rsa, and id_dsa. Encrypted keys require an agent because git-agent never prompts. Hosts must exist in ~/.ssh/known_hosts.

Normal indexing reuses exact matching chunk embeddings from compatible indexes for the same project or cached remote. This includes filesystem-to-revision and revision-to-revision reuse, so searching a nearby commit usually embeds only its changed chunks. Compatible indexes also reference one shared on-disk vector payload per project or remote cache instead of copying unchanged vectors into every snapshot. Existing local vector payloads migrate on a later cache write. --reindex skips cross-index reuse, rebuilds the selected source, and appends a new shared vector generation without changing older snapshots. Interrupted cache writes remain incomplete and rebuild on the next search instead of being used as completed indexes.

Remote indexing can overlap download and embedding, reducing first-search and refresh time when the remote supplies selected files early enough.

Useful flags:

Flag	Purpose
--scope <paths>	Limit search or indexing; local paths are current-directory-relative, remote paths are repository-relative
--rev <rev>	Search a committed Git tree
--remote <url>	Search a cached remote Git repository URL
--code	Include source-code files only
--no-tests	Exclude common cross-language test filenames and test directories from results and --ls-files output
--min-relatedness <n>	Set vector relatedness candidate threshold
--limit <n>	Limit result count
--format	Use json|brief for search, text|json for --ls, text|json|completion for --ls-remotes, and tree|json for --ls-files
--index	Build missing embeddings without searching
--reindex	Rebuild existing embeddings and drop stale cache entries
--agent	Use agent-friendly brief output and serve remote-fetch details and indexing progress on a private local socket when work is needed
--ls	List search indexes for the current project or --remote cache without embedding or querying
--ls-remotes	List cached remote repositories without embedding, fetching, or querying
--ls-files	List files in the selected search index without embedding or querying; --no-tests filters listed paths without changing the selected index

Index inspection commands:

git-agent search --ls
git-agent search --ls --format json
git-agent search --ls-remotes
git-agent search --ls-remotes --format json
git-agent search --ls-remotes --format completion
git-agent search --ls-files
git-agent search --ls-files --format json
git-agent search --ls-files --no-tests
git-agent search --ls-files --rev HEAD --scope internal/
git-agent search --ls-files --remote https://github.com/yusing/git-agent.git

Remote --ls output shows the cached bare-repository path even when no completed search indexes exist, followed by each available index path.

Use docs/spec.md for exact cache layout and index-selection contracts.

See git-agent search --help and docs/spec.md for exact output, cache, ignore-file, and debug behavior.

CLI Reference

Everyday commands:

git-agent commit-msg [--amend] [flags]
git-agent commit [--amend] [flags]
git-agent pr-message [flags]
git-agent release-note [--out <file>] [flags] <base> <release>
git-agent release-note [--out <file>] [flags] patch|minor|major
git-agent review [--codebase|--uncommitted|--staged] [flags] [prompt...]
git-agent review --wait <id>
git-agent search [flags] <query...>
git-agent search --ls [--remote <url>] [--format text|json]
git-agent search --ls-remotes [--format text|json|completion]
git-agent search --ls-files [--format tree|json] [--remote <url>] [--rev <rev>] [--scope <paths>] [--no-tests]
git-agent simplify [--codebase|--uncommitted|--staged] [flags] [prompt...]
git-agent simplify --wait <id>
git-agent config index.remote [<git-url>]
git-agent config --unset index.remote
git-agent index sync

Common generation and inspection flags:

Flag	Purpose
--model <name>	Override command default and OPENAI_MODEL
--fast	Request fast service tier
--low, --medium, --high, --xhigh	Set reasoning effort
--base-url <url>	Override provider base URL
--timeout <duration>	Set request timeout; review/simplify default to none
--max-steps <n>	Bound agent loop steps
--max-web-searches <n>	Review/simplify only: override hosted-search cap
--guidance-family auto|agents|claude|codex|none	Force guidance family
--append-prompt <text>	Add a bounded operator hint
--debug	Print diagnostics
--pprof <addr>	Serve Go pprof endpoints

release-note --out <file> writes the rendered Markdown to the file and streams a human console trace to stdout.

Configuration

Persistent settings are stored in ${XDG_CONFIG_HOME:-~/.config}/git-agent/config.json. index.remote is global. Displayed URLs redact URL credentials; sync uses same Git transport and authentication behavior as search --remote, without invoking git executable or interactive credential prompts.

Skill discovery honors Codex [[skills.config]] entries in $CODEX_HOME/config.toml (default ~/.codex/config.toml), including enabled = false.

Default auth comes from:

~/.codex/auth.json

The file must include ChatGPT auth:

{
  "auth_mode": "chatgpt",
  "tokens": {
    "access_token": "...",
    "account_id": "..."
  }
}

ChatGPT auth sends requests to https://chatgpt.com/backend-api/codex with Authorization: Bearer <access_token> and ChatGPT-Account-ID: <account_id>. Requests also identify the Codex client by sending originator: codex_cli_rs and User-Agent: codex_cli_rs.

When ~/.codex/auth.json is absent, OPENAI_API_KEY is used as a legacy OpenAI-compatible fallback. OPENAI_BASE_URL only applies to that fallback path unless --base-url is passed explicitly.

Supported environment variables:

Variable	Used for
OPENAI_API_KEY	Message-generation fallback auth and search fallback auth
OPENAI_BASE_URL	Message-generation fallback base URL and search fallback base URL
OPENAI_MODEL	Message-generation model; defaults to gpt-5.6-luna
OPENAI_EMBEDDING_API_KEY	Search embedding auth
OPENAI_EMBEDDING_BASE_URL	Search embedding base URL
OPENAI_EMBEDDING_MODEL	Search embedding model
OPENAI_EMBEDDING_DIMENSIONS	Search embedding dimensions
OPENAI_EMBEDDING_MAX_INPUT_CHARS	Search per-input character cap
OPENAI_EMBEDDING_BATCH_INPUTS	Search embedding request input count
OPENAI_EMBEDDING_BATCH_MAX_CHARS	Search embedding request character budget
OPENAI_EMBEDDING_CONCURRENCY	Search embedding request concurrency

CLI flags override environment values.

With ChatGPT auth, the gpt-5.6 alias resolves to gpt-5.6-sol. The canonical gpt-5.6-sol, gpt-5.6-terra, and gpt-5.6-luna identifiers pass through unchanged.

Behavior defaults:

• service_tier is omitted unless --fast is set.
• Reasoning effort is omitted unless --low, --medium, --high, or --xhigh is set.
• --append-prompt can steer style or emphasis only when consistent with the task contract and repository evidence.

How It Works

flowchart TD
    Start["git-agent command"] --> Inspect["Typed Git inspection"]
    Inspect --> Context["Prepared task context"]
    Context --> Guidance["Project guidance and skills"]
    Guidance --> Agent["Bounded read-only agent loop"]
    Agent --> Validate["Validate and shape output"]
    Validate --> Output["stdout, file, or git commit"]
    Inspect --> Search["search: embed and rank local chunks"]
    Search --> SearchOutput["JSON or brief stdout"]

Loading

review and simplify stream events from memory over SSE. Detached runs persist only a small task record under:

~/.git-agent/<project-identity-sha>/background/<task-id>.json

Failed task records include bounded debugging context: model/mode identity, launch repository fingerprint, and recent sanitized tool-call/tool-output summaries. They do not contain provider credentials, full requests/responses, or an unbounded repository trace.

Git repositories with origin use the SHA-256 of its normalized repository identity, so common SSH and HTTPS URL spellings and separate clones share task records. Projects without origin use the cleaned absolute project-path SHA.

Search indexes use a project identity metadata root:

~/.git-agent/<project-identity-sha>/search/

As with background records, Git repositories with origin use normalized origin identity and otherwise fall back to the cleaned absolute path.

On the next run for an existing project, legacy metadata from <project>/.git-agent/ is migrated into the home metadata directory automatically.

Local Development

shadowtree build
shadowtree test
shadowtree install prefix=/usr/local

shadowtree install builds and installs the binary without writing a build artifact into the repository. It accepts destdir for package-style installs.

Install arguments and environment defaults:

Input	Default
prefix	$HOME/.local
destdir	empty
fish_config_dir	$XDG_CONFIG_HOME/fish, or $HOME/.config/fish

Fish completions install under <fish_config_dir>/completions when the fish config directory already exists.

Security and Privacy

• Model tools are read-only and bounded.
• No arbitrary shell command tool is exposed to the model.
• commit and commit --amend are explicit Git write commands, run only after message generation.
• Normal Git config, hooks, signing, and gpg-agent behavior apply when creating commits.
• Message generation sends prepared repository context to the configured provider.
• Review and simplify may send model-authored public documentation queries to provider-hosted web search and optional Context7; prompts forbid repository content and sensitive data in those queries.
• Search sends indexed chunks and queries to the configured embedding provider.
• API keys and bearer tokens are redacted from debug output and errors.
• Repository tools do not follow symlinks outside the repository.
• Metadata and indexes under ~/.git-agent/ are restricted to the current user on platforms with Unix-style permission bits.
• Detached task records contain producer metadata and the exact terminal final or error event. Failed records also contain bounded sanitized diagnostics. Records are owner-only and retained indefinitely so a completed report remains retrievable.

Specification

docs/spec.md is the normative behavior contract for commands, flags, stdout/stderr, tracing, search indexing, guidance discovery, and model tool limits. Keep README changes user-facing; update the spec when behavior or contracts change.