Front an API you already run

A fronted origin is an API you already run, answering a product's Verbs after the gate has admitted, priced and metered each call.

A lookup, frontedCopy Anchor Link

A lookup by domain that already runs on its own server fronts it, priced per answer, keeping its old paths.

import { define, secret } from 'apis.dev'

/** Any company by its domain, with its headcount and sector, from the server that already answers it. */
export default define({
  name: 'companyfacts', domain: 'companyfacts.apis.dev',
  sources: {
    legacy: {
      origin: 'https://api.example.com', key: secret('LEGACY_KEY'),
      front: {
        'Company.get':    'GET /v2/companies/{domain}',
        'Company.search': 'GET /v2/companies',
      },
      paths: 'keep',                        // /v2/companies/acme.com still answers
    },
  },
  Company: { domain: 'url!#', employees: 'number?', sector: 'string?' },
  offer: {
    'Company.get': 0.002, 'Company.search': 0.005,
    free: { 'Company.get': 100 },
  },
})

The reply is the origin's body, checked against Company, with the product's headers on it.

HTTP/1.1 200 OK
Content-Type: application/json
X-Cost: price=0.002, currency="USD"
X-Receipt-Id: rcpt_9
X-Request-Id: req_1f7c3a9e0d28b56e4c19

{
  "domain": "acme.com",
  "employees": 240,
  "sector": "Software"
}

Old callers change nothingCopy Anchor Link

With paths: 'keep', each fronted route also answers at its old path, beside the Verb's own address.

Imported Keys keep working under their old prefix, as an import leaves them. From Launch, the old hostname points at the product as one of your Domains, so an old client changes no line.

A refused call costs nothing and never reaches the origin. A call the origin fails, or does not answer in time, answers 502 origin_failed at no charge, and alerts your on-call route.

What the front adds, and what it leavesCopy Anchor Link

The origin keeps its logic and its records. The product adds everything a seller needs around it.

The origin receives the call with the Source's credential and three headers: Apis-Customer, Apis-Request-Id and Apis-Signature. The signature lets the origin refuse any call that skipped the gate.

Port one Verb at a timeCopy Anchor Link

To move a Verb off the origin, give its fields a from and a map, or a Function. Then remove its line from front.

Its address, its price and every Key stay as they were, so a Customer never sees the move. When front holds no line, the origin can stop.