Echo

User-pays AI infrastructure. Drop in Echo, users pay for their own usage—you never front costs.

Skip the hard choice between fronting API costs, high-friction BYOK flows, or building billing from scratch.

Read the docs | Live demo | Read our announcement

The Problem

Building AI apps forces you to pick your poison:

Approach	Developer Cost	User Experience	Revenue Model
BYOK	None (but no revenue)	Complex key management	None
Dev API Key	Unpredictable burn rate	Simple	Need metering + billing
Bill End Users	Weeks building infra	Simple	Auth + Stripe + metering

Echo eliminates all three problems.

How Echo Works

Replace your AI SDK imports with Echo. Users authenticate once, get a balance, and pay for their own usage. You set a markup and earn revenue automatically.

Before:

// Option 1: Front costs yourself
import { openai } from '@ai-sdk/openai';
import { generateText } from 'ai';
const response = await generateText({
  model: openai('gpt-5'),
  'YOUR-API-KEY',
  prompt: '...'
});

After:

// Users pay, you earn markup, zero infrastructure
import { useEchoModelProviders } from '@merit-systems/echo-react-sdk';
import { generateText } from 'ai';

const { openai } = useEchoModelProviders();
const response = await generateText({
  model: openai('gpt-5'),
  prompt: '...',
});

Quick Start

pnpx echo-start@latest

Creates a new app with Echo pre-configured. Live in 2 minutes.

Why Echo?

No hosting costs - Users pay providers directly through Echo. You never proxy requests or front bills.

Better UX - One OAuth login replaces complex BYOK flows. Users get a universal balance across all Echo apps.

Instant revenue - Set a markup percentage. Every token generates profit automatically.

Zero infrastructure - No payment processing, no usage tracking, no key validation. Echo handles it all.

Core

• Echo Control: Next.js app for echo.merit.systems. Hosted site and api routes.
• Echo Server: Express server for router.echo.merit.systems. Proxy for routing and metering LLM requests from clients.

SDKs

• Echo TS SDK Typescript SDK that all the framework specific SDKs are built on top of.
• Echo Next.js SDK SDK for simple Next.js 15+ App Router integration.
• Echo React SDK SDK for simple React client side SPA integration.

Examples

• Echo Next.js Example
• Echo React SDK

Templates

Get started quickly with echo-start:

pnpx echo-start gen-ai-app

Available templates:

• next - Next.js application with Echo
• react - Vite React application with Echo
• nextjsChatbot - Next.js with Echo and Vercel AI SDK
• assistantUi - Next.js with Echo and Assistant UI

Or run npx echo-start my-app to choose interactively.

Development

Fill out packages/app/control/.env and packages/app/server/.env. Then...

• pnpm i
• pnpm dev