Presets Overview

Presets are pre-configured middleware stacks for common agent types. One function call gives you production-grade guardrails, search, observability, and more.

How presets work

A preset is a function that returns Middleware[]. You pass it to agent.use() just like any other middleware:

import { Agent } from "agent-express"
import { supportBot } from "@agent-express/preset-support"

const agent = new Agent({
  model: "anthropic/claude-sonnet-4-6",
  instructions: "You are a helpful support agent.",
})

agent.use(supportBot({ tone: "empathetic" }))

Under the hood, supportBot() composes 8+ middleware into a single array: budget caps, timeouts, PII redaction, tone enforcement, rate limiting, escalation, and more. Every default is overridable or disableable.

Available presets

Preset	Package	Use case
Support Bot	@agent-express/preset-support	Customer support with RAG, PII, escalation, tone

Writing your own preset

A preset is just a function that returns middleware:

import type { Middleware } from "agent-express"
import { guard, observe, memory } from "agent-express"

export function myPreset(config?: MyConfig): Middleware[] {
  return [
    guard.budget({ limit: config?.budget ?? 1.00 }),
    guard.timeout({ turn: 30_000 }),
    observe.log(),
    memory.compaction({ maxTokens: 8192 }),
  ]
}

This follows the same pattern as built-in presets. No special API needed.