REST

Production

REST API (Any HTTP Service) — Any HTTP API

Overview

SettleGrid supports any standard REST API as a first-class protocol. If your service exposes HTTP endpoints (Express, Fastify, Next.js, Hono, Flask, Rails — anything), you can add per-call billing with SettleGrid's REST middleware. No MCP server required, no protocol adapters needed — just HTTP request/response with billing built in.

How It Works

The REST integration uses SettleGrid's settlegridMiddleware() function, which wraps your HTTP route handler with billing logic. On every incoming request, the middleware extracts the API key from the x-api-key header (or Authorization: Bearer), validates the key and credit balance via SettleGrid's API, and either allows the request through or returns a 401/402 error.

After your handler processes the request and returns a response, the middleware fires an asynchronous metering event to record the invocation. The metering is non-blocking — it does not add latency to the response.

The REST middleware works with any Node.js HTTP framework. For Express, it attaches as standard middleware. For Next.js App Router, it runs at the top of your route handler. For other languages (Python, Go, Ruby), you can call the SettleGrid REST API directly.

How SettleGrid Integrates

Use settlegridMiddleware() from '@settlegrid/mcp/rest' to wrap any HTTP route handler. The middleware handles key extraction, validation, balance checking, and metering automatically. It works with Express, Fastify, Next.js, Hono, and any other Node.js framework. For non-Node environments, call POST /api/sdk/validate-key and POST /api/sdk/meter directly.

Key Specs

Protocol	REST — REST API (Any HTTP Service)
Backer	Any HTTP API
Detection Header	x-api-key / Authorization: Bearer sg_*
Identity Type	api-key
Payment Type	credit-balance
Status	Production

Code Example

Here is how a developer's tool works with REST via SettleGrid:

rest-example.tstypescript

import { NextRequest, NextResponse } from 'next/server'
import { settlegridMiddleware } from '@settlegrid/mcp/rest'

const billing = settlegridMiddleware({
  toolSlug: 'my-rest-api',
  pricing: { defaultCostCents: 10 },
})

export async function POST(request: NextRequest) {
  // Billing middleware — validates key + deducts credits
  await billing(request)

  const body = await request.json()
  const result = await processRequest(body)
  return NextResponse.json({ result, metered: true })
}

Start monetizing with SettleGrid

Free forever — 50,000 ops/month, progressive take rate. Add billing to your REST tool in under 5 minutes.

Get Started Free