Nac

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

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
  • Release lifecycle
  • AGENTS.md Files
  • Skills
  • Sandbox
• Configuration
  • Data stores
  • 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).

The supported source workflow starts with one dependency setup per fresh worktree:

make setup
make dev

make dev runs the Rust API at http://127.0.0.1:3210 and the React app at http://127.0.0.1:5173, with Vite HMR and API proxying. Both process trees are supervised together; Ctrl-C or either process failing stops the other. Use make build to rebuild the committed frontend bundle and compile the complete production-embedded debug application, then make run to build and run that production-equivalent application from the current checkout. Set RUN_BIND=127.0.0.1:4321 when the default port is already in use.

For day-to-day use without replacing a stable installation, install the source build under its development name:

make install-dev
# defaults to $HOME/.local/bin/nac-web-dev

make install-dev DEV_INSTALL_DIR="$HOME/bin" DEV_BIN_NAME="nac-my-branch"

Source builds have the dev build track and report the exact source revision. Without an override they use dev.db under NAC_HOME (or the normal NAC configuration directory), isolated from beta.db and stable.db. Set NAC_HOME=/path/to/branch-state for a fully separate development home, or pass DEV_STORE_PATH=/path/to/branch.db to make dev and --store-path to the installed executable. Configuration-level storage overrides remain authoritative too. Database migrations are forward-only: when testing revisions that may move backward across an incompatible schema, use a disposable per-worktree or per-branch store rather than a shared development database.

The local verification lanes are make test-web for frontend unit/component tests, make test-e2e for isolated real-browser tests against the embedded server and a credential-free scripted model, and make test-durability for the focused lifecycle/crash-window regressions. make test-managed-load runs the bounded deterministic 1/2/4-orchestrator load and fault scenario described in the managed-load guide. Install the E2E browser once with npm --prefix crates/nac-server/web exec -- playwright install chromium. make ci is the portable unit, lint, formatting, and committed-asset lane. Run make test-e2e as the matching production-browser release gate and make test-durability as a faster focused rerun of crash-window contracts that are also covered by the broader Rust suites. Release packaging and installer checks remain workflow-only.

For an explicitly provisioned remote Managed NAC using the legacy BasicAuth gateway, set

NAC_E2E_REMOTE_URL
NAC_E2E_REMOTE_USERNAME
NAC_E2E_REMOTE_PASSWORD

through a private runtime secret source and run make test-e2e-remote. This lane verifies gateway denial, authenticated health/readiness, release identity, and production-client loading without modifying remote state. Optionally set NAC_E2E_REMOTE_EXPECTED_VERSION to pin the expected release.

For a portal-owned host, set NAC_E2E_REMOTE_AUTH_MODE=portal-launch, keep NAC_E2E_REMOTE_URL at the HTTPS host root, and inject the single-use URL as NAC_E2E_REMOTE_LAUNCH_URL; do not set the BasicAuth variables. The launch URL must use the exact target origin and managed launch route. Portal mode redeems it once into an isolated browser context, disables trace, screenshot, and video artifacts before redemption, and refuses DEBUG or PWDEBUG. An optional NAC_E2E_REMOTE_ENVIRONMENT non-secret label is included with the recorded build and schema identity.

Never put remote credentials, launch URLs, or cookie values in Git, command arguments, shell history, test artifacts, or CI logs. The remote smoke lane complements rather than replaces the isolated local make test-e2e suite, and it remains non-mutating in both authentication modes.

nac is licensed under Apache 2.0.