avm

A version manager for AI coding agents. Think nvm for AI coding agents. avm provides reproducible agent execution environments, project-level configuration, and isolated agent runtimes.

Features

• Install specific versions of AI coding agents
• Use different agent versions per project
• avm.config.json project configuration
• Reproducible agent environments under ~/.avm

Supported Agents

• @openai/codex
• @anthropic-ai/claude-code
• @google/gemini-cli

Getting Started

Install the CLI

npm install -g @combinatrix-ai/avm

Installing an Agent

avm install codex                # installs latest @openai/codex
avm install codex@0.45.1         # installs @openai/codex@0.45.1
avm install claude               # installs @anthropic-ai/claude-code
avm install gemini               # installs @google/gemini-cli

# override package if needed
avm install codex --package @your-scope/codex-cli
avm install codex --registry https://registry.npmjs.org     # custom registry

Listing Agents

Installed

avm list

Remote (including not installed)

avm list --remote # list npm packages of coding agents

Using an Agent

avm global codex@0.60.1   # set global default when no avm.config.json
avm                       # start default agent (global or from avm.config.json)
avm -v                    # show avm CLI version
avm self-update           # update avm itself via npm -g

avm self-update and update checks

• avm self-update runs npm install -g @combinatrix-ai/avm@latest under the hood (or --to <version> for a specific version).
• avm will periodically check the npm registry (at most once per day) and print a message if a newer version of avm is available.
• Set AVM_NO_UPDATE_CHECK=1 to disable the automatic update check.

Configuration & state

You configure per-project defaults via avm.config.json, and avm keeps global installation and “current agent” state under ~/.avm.

avm.config.json (project config)

• File name: avm.config.json
• Location: searched from the current directory upward until found; the nearest one wins.
• Purpose: define project-level defaults for which agent to run, which package/version to use, and what default args to prepend.

You can create or update it manually, or via:

avm local codex@0.60.1    # writes or updates avm.config.json in this directory
avm local codex -a "--dangerously-bypass-approvals-and-sandbox"  # set default args in avm.config.json

Example avm.config.json:

{
  "default": {
    "name": "codex"
  },
  "codex": {
    "version": "0.45.1",
    "args": "resume"
  },
  "claude": {
    "args": "resume"
  },
  "gemini": {
    "package": "@your-scope/gemini-cli"
  }
}

avm # Start codex with args provided
avm claude           # Start claude with its args from avm.config.json

When you run avm inside the project, it will prefer the agent specified in the nearest avm.config.json.

How it works

• Agents install into ~/.avm/agents/<name>/<version> via npm install --prefix.
• Binaries are resolved from the package bin field (fallback to node_modules/.bin/<package>).
• State is stored in ~/.avm/state.json and updated when you global or run an agent.

Files under ~/.avm

Files

• ~/.avm/agents/<name>/<version>/.meta.json
  • Written by avm install <agent>, avm global <agent>, and when running an agent.
  • Stores installation metadata: { name, package, version, args, installedAt }.
• ~/.avm/state.json
  • Updated by avm global <agent> and whenever you run an agent via avm ....
  • Stores the current agent under current (plus timestamps and any future state).

What each command updates

• avm install <agent>:
  • Ensures the agent is installed under ~/.avm/agents/<name>/<version> and writes/updates .meta.json there.
  • Does not modify ~/.avm/state.json or any avm.config.json.
• avm global <agent> [--args "<agent-args>"]:
  • Ensures the agent is installed and updates the corresponding .meta.json (including args when provided).
  • Updates ~/.avm/state.json (the current agent: name, package, version, args).
  • Does not touch avm.config.json.
• avm local <agent> [--args "<agent-args>"]:
  • Creates or updates avm.config.json (nearest in the directory tree): sets "default.name" and per-agent version / args.
  • Does not install the agent or change ~/.avm/state.json or any .meta.json.

Resolution rules when running avm

When avm decides what to run, it combines CLI input, project config, and saved state:

• Agent name:
  1. CLI <agent> / <agent>@<version> (e.g. avm codex@0.60.1)
  2. avm.config.json.default.name (nearest config in the directory tree)
  3. ~/.avm/state.json.current.name (last used / global default)
• Package name:
  1. CLI --package
  2. avm.config.json["<agent-name>"].package
  3. ~/.avm/state.json.current.package for that agent
  4. Built-in defaults (codex → @openai/codex, etc.)
• Version:
  1. <agent>@<version> in the CLI (e.g. codex@0.60.1)
  2. avm.config.json["<agent-name>"].version
  3. ~/.avm/state.json.current.version for that agent
  4. "latest"
• Default args:
  1. avm.config.json["<agent-name>"].args (project-scoped defaults)
  2. ~/.avm/state.json.current.args / .meta.json for that agent (set via avm global <agent> --args "..." or previous runs)
  3. No default args

Default args are prepended to the agent process arguments before any extra CLI arguments you pass after the agent name (e.g. avm codex -- extra flags).

Roadmap

• Optional fully-managed Node runtimes
• Agent marketplace / registry
• Lockfile for full reproducibility
• Agent diff / compare functionality

Development & Release

Basic release flow (handled by GitHub Actions):

1. Make code changes and ensure tests pass: npm test

2. Bump the version with npm (do not edit package.json manually):

   npm version patch   # or: minor / major

   This updates package.json, creates a commit, and tags vX.Y.Z.

3. Push the branch and tags:

   git push origin main --follow-tags

4. The Publish Package workflow (triggered by the v* tag) runs tests and publishes @combinatrix-ai/avm to npm.

Avoid running npm publish locally; prefer the CI-based publish flow above.