Email Validation API
Verify in Realtime
Use a simple API call to verify addresses during signup, enrichment, AI agent workflows, or custom list-processing pipelines.
Structured JSONReal-time responseSMTP verification
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Email Validation API
One endpoint for every verification type. Real-time SMTP checks, structured JSON responses, and native MCP and Agent Skills integration.
All Verification Modes, One Endpoint
Every verification type is accessible through the same REST API.
Single Email Verification
POST /verify — real-time SMTP check with sub-3s response. Returns status, deliverability, quality score, and risk flags in one JSON object.
Batch Verification
POST /verify/batch — verify up to 50 addresses per call, synchronously. All results returned in a single response, same schema as single verification.
Async File Processing
POST /verify/file — submit CSV or Excel files for background processing. Results delivered via webhook callback when the job completes.
Official SDKs
Type-safe client libraries for Python, Node.js, Go, and PHP. Auto-retry on failure, full error handling, and identical response types across all languages.
What Every Verification Includes
Every API call runs the same multi-layer check automatically.
Free Email Checker
Check individual emails for validity, deliverability, and reputation. No account required.
Disposable Email Detection
Identify and block temporary email services before they pollute your list.
Bounce Email Checker
Detect emails likely to bounce before sending, protecting your sender reputation.
Webhook Support
Receive results asynchronously and query message history.
Async Delivery
Create Webhooks
Register HTTP endpoints to receive verification results the moment a job or batch completes. Supports custom payloads, automatic retry on failure, and per-job or global configuration.
- Job completion events with result summary
- Automatic retry on failed delivery
- Per-job or account-level configuration
Message History
Query Messages
Access the full webhook event log to retrieve past results, debug delivery failures, or replay missed notifications. Events are retained for 30 days.
- Query events by job ID or date range
- Replay missed or failed deliveries
- 30-day event retention
AI-Native Integration
Connect to every major AI client and SDK without writing verification logic from scratch.
MCP Server
Verify emails in Claude Desktop and Cursor with natural language. Ask "is this address valid?" and get instant results — no API key setup, no code required.
AI Agent Skills
One-click skills for Claude, Manus, and other agent platforms. Email validation runs automatically inside any workflow without manual configuration.
Tool Use & REST
Call the REST API directly from LangChain, CrewAI, any Anthropic or OpenAI SDK, or any HTTP client. Structured JSON parses without transformation — status, score, and flags included.
Explore More Features
Every AI-native verification tool in one platform.
MCP Server
Verify emails in Claude Desktop and Cursor with natural language. No code required.
AI Agent Skills
One-click skills for Claude, Manus, and other agent platforms. Automatic email validation in any workflow.
Email Verification
Verify individual addresses with real-time SMTP checks and instant results.
Frequently Asked Questions
1. How fast is the API?
Cached results return in under 200ms. Full SMTP verification completes in 1–3 seconds on average. The API supports up to 6,000 single verification requests per minute and 1,500 batch requests per minute.
2. How do I integrate the API?
The API uses standard REST calls with JSON responses. Official SDKs are available for Python, Node.js, Go, and PHP. Most integrations complete in under 30 minutes. The MCP Server and Agent Skills require no code at all — install once and verification works in any supported AI client.
3. What does the API cost?
Pay-as-you-go starts at $0.005 per verification with no monthly fees. Volume pricing goes as low as $0.001 per email for 1M+ credits. A free tier provides 100 verifications daily with no credit card required.
4. What does each API response include?
Every response includes the verification status (deliverable, undeliverable, risky, or unknown), a quality score from 0–100, a risk level, and reason codes. Disposable email flag, role account flag, catch-all detection, and typo correction suggestions are also included.
5. Is the API secure?
All requests use HTTPS. API key authentication is required on every call, and IP whitelisting is available for additional security. BillionVerify is fully GDPR and CCPA compliant with automatic data deletion after processing.
6. How do AI agents and LLMs use this API?
AI agents connect through the MCP Server (natural language in Claude and Cursor), pre-built Agent Skills (one-click install for Claude and Manus), or direct REST calls from LangChain, CrewAI, or any Anthropic or OpenAI SDK. All methods return the same structured JSON — no response transformation needed.
Email Validation API
Get Your API Key
One endpoint for every verification type. MCP Server and Agent Skills included. 100 free verifications daily, no credit card required.
100 free verifications daily · Native MCP Server integration · No credit card required
99.9%
Accuracy
Real-time
API Speed
$0.00014
Per Email
100/day
Free Forever