I built a webhook testing API in one day and listed it on RapidAPI for free

The Problem

Every developer integrating M-Pesa, Stripe, GitHub, or any service

that sends webhooks hits the same wall during development:

You need a URL to receive the webhook. But your app is running on

localhost. So you either:

• Deploy just to test (slow)


• Use ngrok (another tool to manage)


• Hard-code a URL and hope for the best

I got tired of this on every project. So I built an API that solves

it in one call.

What I Built

WebhookBox — an API that gives you instant, disposable webhook

URLs for capturing, inspecting, and replaying HTTP payloads.

// Step 1: Create a webhook URL

const response = await fetch(

  'https://webhookbox-api-production.up.railway.app/webhooks/create',

  { method: 'POST' }

)

const { webhook_url, webhook_id } = await response.json()



// Step 2: Point M-Pesa/Stripe/GitHub at webhook_url

// Step 3: Inspect what was received

const payloads = await fetch(

  `https://webhookbox-api-production.up.railway.app/webhooks/${webhook_id}/payloads`

)

That's it. No setup. No config. No ngrok.

What It Does

• 
  Create a disposable webhook URL instantly


• 
  Capture any HTTP method — POST, GET, PUT, PATCH


• 
  Inspect full payload: headers, body, query params, timestamp


• 
  Replay any captured payload to a target URL


• 
  Auto-expires after 24 hours

The Stack

• Node.js + Express


• Upstash Redis (for payload storage with TTL)


• Deployed on Railway (free tier)


• Listed on RapidAPI

Why This Is Useful in CI/CD

The real power is automating webhook testing in your pipeline:

// In your test file

const { webhook_id, webhook_url } = await createWebhook()



// Trigger your payment flow

await triggerMpesaPayment({ callback_url: webhook_url })



// Wait, then assert

await sleep(3000)

const { payloads } = await getPayloads(webhook_id)

assert(payloads[0].body.ResultCode === 0)

No human sitting watching a browser tab. Fully automated.

Try It Free

Listed on RapidAPI with a free tier:

👉