Built-in agents

nui ships with built-in agents for the home launcher, common coding-agent CLIs, and API providers. Each session resolves to an ADL definition; single-step agents dispatch directly to the harness.

Master agent

Agent	ADL id	Role
nui	`nui`	Home launcher / router. Uses `nui-orchestrator` MCP tools (`list_agents`, `launch_session`) to open specialist sessions, and can create agents via the create-agent skill. Legacy id: `nui-orchestrator`.

The home screen calls POST /api/orchestrate. The master’s harness comes from Settings → Default harness (defaults to Anthropic API).

CLI agents

Agent	Harness	CLI
Claude Code	`claude-code`	`claude -p … --output-format stream-json`
pi	`pi`	`pi --mode rpc` (JSON-RPC over stdin/stdout)
codex	`codex`	`codex exec … --json`
opencode	`opencode`	`opencode serve` + `opencode run --attach`

Persistent sessions are maintained per harness — Claude Code, pi, codex, and opencode each keep their own session state across turns.

Built-in CLI agents are pinned to their matching harness. Custom CLI agents can allow a subset (or all) of CLI harnesses via ADL allowedHarnesses; the New Session panel then offers a harness picker, and CLI accepts --harness.

API agents

API agents run in-process without a CLI binary:

ADL id	Name	Provider
`anthropic`	Claude API	Claude models via the Anthropic API
`openai`	OpenAI	GPT models via the OpenAI API
`gemini`	Gemini	Google Gemini via the Gemini API
`openrouter`	OpenRouter	Multi-model routing via OpenRouter
`ollama`	Ollama	Local models via Ollama

See the harness design doc for API harness configuration and environment variables.

Sandbox variants

Built-in CLI agents support three sandbox modes:

none — runs unsandboxed on the host
bubblewrap — Linux-only namespace isolation with bind mounts for agent config dirs
docker — runs in a managed Docker container (nui-claude-code:latest, nui-pi:latest, etc.)

Set harness.sandbox in the ADL definition or pick the variant when creating a session.