Long-running agent task harness for threads and episodes

Arcee • Documentation • Releases • Arcee Open Model API

nac is an open-source agent harness for longer, ambitious tasks — experiments, training runs, infrastructure, and prototyping that has to stay aligned with the original intent. It uses a thread-and-episode architecture inspired by slate: a central orchestrator plans and decomposes work but cannot execute commands or edit files; it only launches threads, which return episodes — structured summaries of what they accomplished. Also takes inspiration from nanocode and pi. For the technical write-up, see the nac blog post.

Quickstart

By Hand. Install the latest stable release:

curl -fsSL https://raw.githubusercontent.com/arcee-ai/nac/main/scripts/install.sh | sh

The installer puts nac-web in $HOME/.local/bin. Add that directory to your PATH if needed, then start the dashboard from your project,

nac-web

and navigate to the interface in your browser (default: http://127.0.0.1:3210).

By Agent. Nac provides a portable onboarding skill and MCP integration; paste this into your chosen agent harness to install nac, configure it, and connect the MCP:

Install the nac onboarding skill with curl -fsSL https://raw.githubusercontent.com/arcee-ai/nac/main/scripts/install-skill.sh | sh -s -- --target agents, load nac-onboarding, and walk me through installing nac, selecting Arcee login, ChatGPT Codex login, or an OpenAI-compatible API key, adding MCP servers, and connecting your MCP client to nac.

Upgrade. Nac ships with a native upgrade function which can be used to install the latest stable release of nac.

nac-web upgrade

# Upgrade to the latest nightly release candidate
nac-web upgrade --pre-release

Model Provider Authentication

Pick one before you start a session, or configure it later from the dashboard.

# Recommended: Arcee device-code login → Latest Open & Arcee Trinity models
nac-web arcee-auth login

# ChatGPT account via OAuth → OpenAI models
nac-web codex-auth login

# Any catalog provider (DeepSeek, Fireworks, Together, OpenAI, Anthropic, arcee-api, …)
export OPENAI_API_KEY=...   # or ANTHROPIC_API_KEY, TOGETHER_API_KEY, ARCEE_API_KEY, …

More details can be found in Providers and logins and Model configuration.

Uninstall

curl -fsSL https://raw.githubusercontent.com/arcee-ai/nac/main/scripts/uninstall.sh | sh

Documentation

• Usage
  • AGENTS.md Files
  • Skills
  • Sandbox
• Configuration
  • Example config
  • Model configuration
  • Catalog and cost
  • Providers and logins
• HTTP API
• Model request security

Contributing

Pull requests are welcome. A CLA-signing bot checks every PR against arcee-ai's CLA; comment I have read the CLA Document and I hereby sign the CLA on your PR to sign it (or recheck to re-run the check).

nac is licensed under Apache 2.0.