Add an Agent

An agent is just an AgentConfig — name, systemPrompt, tools, rules, and a model — dropped in a folder under agents/ as agents/<name>/index.ts. Once it's there it's picked up automatically, no registry to edit, no import to add. See Directory Structure for the full folder layout. There are two ways to create that folder.

Command line

npx loopengine add-agent weather-agent
# -> Created agents/weather-agent/index.ts

Generates agents/<name>/index.ts with a working AgentConfig stub, so you don't have to memorize the folder shape by hand. Or skip the command and write the folder yourself — nothing about how an agent gets discovered cares which one you did.

Web interface

Open http://localhost:8787/agents (see Web UI) and use its New agent button — fill in a name and, optionally under Advanced, a system prompt and model provider, then submit. It's the same POST /agents endpoint either way: a real agents/<name>/ folder lands on disk, registered and live immediately, not a database row pretending to be one.

Field defaults

Either way, most fields don't even need to be written out — they default to a conventional path under the agent's own folder:

Field	Defaults to
rules	agents/<name>/actauth.yml (missing → deny everything)
tools	agents/<name>/tools/index.ts's exported tools (missing → no tools)
skillsDirs	agents/<name>/skills (missing → no skills)

There's no subagents field to omit — agents/<name>/subagents/* is its own folder convention (drop another agent's folder there and it becomes one of this agent's tools automatically), always merged into tools on top of whatever the table above resolves to.

The simplest possible agent, agents/weather-agent/index.ts — tools, rules, and skillsDirs all omitted, so they default to agents/weather-agent/tools/, actauth.yml, and skills/:

import type { AgentConfig } from 'loopengine'

export const config: AgentConfig = {
  name: 'weather-agent',
  systemPrompt: 'You answer questions about the weather.',
  model: { provider: 'anthropic', model: 'claude-sonnet-5' }, // reads ANTHROPIC_API_KEY
}

See agents/customer-service/ and agents/file-agent/ for complete, working examples. Once an agent exists, Configure an Agent covers coming back to adjust its prompt, tools, or permission rules.