Skip to main content

​
Welcome to the Vouch API

The Vouch API provides real-time email validation and fraud detection through a simple REST API. Built on Cloudflare Workers, our API delivers sub-second response times from 275+ global data centers.

Base URL

https://api.vouch.expert

​
Quick Example

curl -X POST https://api.vouch.expert/validate \
  -H "Authorization: Bearer your_api_key" \
  -H "X-Project-Id: your_project_id" \
  -H "Content-Type: application/json" \
  -d '{"email": "[email protected]"}'

​
API Versioning

Vouch supports both versioned and unversioned endpoints:
  • Latest (recommended): /validate - Always uses the current stable version
  • Versioned: /v1/validate - Locked to API version 1
We recommend using the latest endpoint for new integrations. Versioned endpoints are available for backward compatibility.

​
Authentication

All API requests require authentication via API keys:

​
Headers

​
Authorization
string
required
Bearer token with your API key
Authorization: Bearer your_api_key_here
​
X-Project-Id
string
required
Your project ID
X-Project-Id: your_project_id

​
API Key Types

Client Keys

For browser and mobile apps
  • Restricted to allowed domains
  • 1,000 requests/hour
  • Safe to expose publicly
  • Includes device fingerprinting

Server Keys

For backend services
  • No domain restrictions
  • 5,000 requests/hour
  • Must be kept secret
  • Can override IP/User-Agent
Server keys are automatically blocked when used from browsers to prevent accidental exposure.

​
Rate Limiting

Key TypeLimitWindow
Client Key1,000 requestsPer hour
Server Key5,000 requestsPer hour
Rate limits are tracked per project. Exceeding the limit returns a 429 Too Many Requests response with a retryAfter header.

​
Quota Management

Each subscription includes a monthly validation quota. Monitor your usage via response headers: 
X-Quota-Limit: 10000
X-Quota-Used: 2345
X-Quota-Remaining: 7655
X-Quota-Reset: 2024-01-01T00:00:00Z
When quota is exceeded, you’ll receive a 402 Payment Required response.

​
Endpoints

POST /validate

Validate an email address with fraud detection

​
Response Format

​
Validation Response

The /validate endpoint returns a structured response: 
{
  "checks": {
    "syntax": { "pass": true, "latency": 2 },
    "disposable": { "pass": true, "latency": 15 },
    "mx": { "pass": true, "latency": 45 }
  },
  "message": null,
  "metadata": {
    "fingerprintHash": "abc123...",
    "previousSignups": 0,
    "totalLatency": 62
  },
  "recommendation": "allow",
  "signals": []
}

​
Error Response

Error responses return an error object with an HTTP status code: 
{
  "error": "Human-readable error message"
}

​
Error Codes

CodeStatusDescription
INVALID_EMAIL400Email address is required or invalid format
INVALID_REQUEST400Request body is malformed
UNAUTHORIZED401Invalid or missing API key
FORBIDDEN403API key doesn’t have access to project
QUOTA_EXCEEDED402Monthly validation quota exceeded
RATE_LIMITED429Too many requests
INTERNAL_ERROR500Server error (contact support)

Complete Error Reference

View all error codes and handling strategies

​
SDKs

We provide official SDKs for popular platforms:

JavaScript

React

Node.js

Next.js

iOS

Android

​
Support

Need help with the API?

Email Support

[email protected]

Dashboard

Manage your projects and API keys

​
Next Steps

Validate Endpoint

Learn about the main validation endpoint

Authentication Guide

Deep dive into API authentication

Error Handling

Handle errors gracefully

Quickstart

Get started in 5 minutes