nac

Small coding agent. Heavily inspired by slate. Also takes inspiration from nanocode and pi.

Install the latest edge build:

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

Pinned version installs are not supported yet.

Set OPENAI_API_KEY, then run nac. Use nac --compact for the compact single-column TUI, or nac --full to override a compact config default.

To use ChatGPT Codex auth instead of an OpenAI API key, run nac codex-auth login and complete the device-code flow in a browser. Launch with nac --backend chatgpt-codex-responses, or configure backend = "chatgpt-codex-responses" under [model].

Optional:

• OPENAI_BASE_URL
• OPENAI_MODEL

Linux installs use the portable static build.

Upgrade to the latest edge build:

nac upgrade

AGENTS.md is loaded hierarchically from the project and globally from NAC_HOME / ~/.config/nac. Skills are discovered from project and user skill directories and activated from workers with activate_skill(...). Sessions are stored in the project store (.nac/store.db by default): use nac resume for the picker, nac resume --last for the newest session, or nac resume SESSION_ID for a specific session. Thread history does not auto-compact right now.

Uninstall:

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

nac can run tools inside a Podman sandbox (requires Podman to be installed):

nac --sandbox

By default this mounts the current directory into the sandbox at /workspace.

For a custom setup:

• --no-mount-cwd disables the default current-directory mount
• --mount HOST:GUEST adds a read-write mount
• --mount-ro HOST:GUEST adds a read-only mount
• --sandbox-image IMAGE overrides the default image (python:3.13-bookworm)

On macOS, start Podman first:

podman machine init
podman machine start

Recommended config

Optional config lives at ~/.config/nac/config.toml, or at $NAC_HOME/config.toml when NAC_HOME is set. Explicit CLI args and environment variables override TOML defaults. Resumed sessions continue using the model and sandbox settings stored in their session snapshot.

The api_key_env setting names the environment variable to read when OPENAI_API_KEY is not set. Store paths remain relative to the launch working directory.

[agents_md]
fallback_filenames = []
max_bytes = 4194304

[ui]
mode = "full"

[storage]
store_path = ".nac/store.db"

[model]
backend = "openai-responses"
model = "gpt-5.5"
base_url = "https://api.openai.com/v1"
reasoning_effort = "xhigh"
api_key_env = "OPENAI_API_KEY"

[sandbox]
image = "python:3.13-bookworm"

[worker]
thread_timeout_secs = 3600

[mcp_servers.exa_web_search]
enabled = true
transport = "streamable_http"
url = "https://mcp.exa.ai/mcp"

[mcp_servers.context7]
enabled = true
transport = "streamable_http"
url = "https://mcp.context7.com/mcp"

[mcp_servers.grep_app]
enabled = true
transport = "streamable_http"
url = "https://mcp.grep.app"

Supported MCP transports right now are stdio and streamable_http. Stdio servers can provide command, args, and env; streamable HTTP servers provide url and optional headers. MCP string values support ${ENV_VAR} expansion.

For ChatGPT Codex auth, the default base URL is https://chatgpt.com/backend-api; NAC sends non-streaming Responses requests to /codex/responses. Use nac codex-auth status to inspect the saved account and nac codex-auth logout to remove local tokens.