Triggers

Start Agent Invocations from server routes, chat surfaces, schedules, or product events.

An Agent Trigger is server-side behavior that starts an Agent Invocation for a specific event.

Triggers are not model adapters. They are not chat platform adapters. They prepare input, context, and run state, then start the Agent.

Route trigger

The simplest trigger is an application route.

server/api/support.post.ts

import { runAgent } from '@vite-hub/agent'
import support from '../agents/support'

export default defineEventHandler(async (event) => {
  return runAgent(support, { runtime: 'nitro' }, await readBody(event))
})

Capability-owned trigger

Some Capabilities own product event behavior. Chat is the clearest example: a chat platform event is adapted into an Agent Invocation through the Chat Capability.

import { chat } from '@vite-hub/agent/capabilities'

export default defineAgent({
  capabilities: [
    chat({
      history: { maxMessages: 20 },
    }),
  ],
  instructions,
  model,
})

The Chat Capability can own webhook autowiring, chat identity, and chat history behavior. The Agent still owns the model-backed invocation.

Schedule trigger

Schedule can start an Agent Invocation, but Schedule is not itself an Agent Capability.

Use Schedule when runtime time is the reason the Agent runs. Use a Capability Trigger when the event belongs to an agent ability.