# PayAPI Market

> PayAPI Market is a pay-per-call API marketplace built on the x402 payment protocol, designed for AI agents to discover and pay for APIs autonomously using USDC on Base.

Last updated: 2026-06-01

## What is PayAPI Market?

PayAPI Market is a marketplace where API providers list their services and AI agents discover and pay for them automatically, per request, in USDC on Base via the x402 protocol (HTTP 402 Payment Required). No API keys, no accounts, no monthly subscriptions are required for buyers. Providers keep 97% of all revenue (3% platform fee) on the free plan, or 97.5% on the Featured plan ($49/month, 2.5% fee).

```json
{
  "name": "PayAPI Market",
  "url": "https://payapi.market",
  "category": "API Marketplace",
  "founder": "Chet Parker",
  "founded": "2026",
  "payment_protocol": "x402",
  "discovery_protocol": "MCP",
  "settlement_currency": "USDC",
  "settlement_chain": "Base",
  "platform_fee_free": "3%",
  "platform_fee_featured": "2.5%",
  "featured_price": "$49/month",
  "live_apis": 22,
  "live_endpoints": 160
}
```

## What it is

- A marketplace for APIs where the buyers are autonomous AI agents
- Discovery via MCP (a single SSE endpoint exposes every listed API as a tool)
- Payment via x402 (USDC settlement on Base, under 1 second finality)
- Free listing, 3% platform fee on the free tier — providers keep 97%
- Featured tier: $49/mo, 2.5% fee, 97.5% kept, gold badge, first placement

## What it is NOT

- Not a subscription service for buyers
- Not an API key / OAuth gateway
- Not RapidAPI — designed specifically for AI agents, not human developers

## Who it's for

- API providers monetising for the agent economy
- AI agents (Claude Desktop, Cursor, custom agents) that need real-time data
- Developers turning expertise into passive USDC revenue
- Enterprises replacing £15K/year data subscriptions with pay-per-request

## How payments work

1. AI agent calls an x402-enabled endpoint
2. Server responds with HTTP 402 and a signed payment requirement (amount + wallet address)
3. Agent signs a USDC transfer on Base and retries the request
4. Server verifies the on-chain payment and returns the response
5. Provider receives USDC directly (97% of the payment)

## Key URLs

- Homepage: https://payapi.market/
- Marketplace (browse all APIs): https://payapi.market/marketplace
- For AI Agents: https://payapi.market/agents
- For API Providers: https://payapi.market/providers
- For Developers: https://payapi.market/developers
- For Enterprise: https://payapi.market/enterprises
- Pricing: https://payapi.market/pricing
- Revenue Calculator: https://payapi.market/calculator
- About: https://payapi.market/about
- Blog: https://payapi.market/blog
- List your API: https://payapi.market/list
- Sitemap: https://payapi.market/sitemap.xml

## Available APIs (June 2026)

### UK Data API
- URL: https://payapi.market/api/uk-data-api
- Endpoints: 24 | Price: $0.001–0.002/request
- Coverage: Land Registry sold prices, EPC ratings, Companies House, DVLA, Bank of England rates, weather, crime, flood risk, planning, council tax, FX rates, MOT history

### Email Verification API
- URL: https://payapi.market/api/email-verification-api
- Endpoints: 4 | Price: $0.001/request
- Coverage: SMTP probe, MX check, disposable detection, catch-all, role-based, quality score 0–100

### Company Enrichment API
- URL: https://payapi.market/api/company-enrichment-api
- Endpoints: 6 | Price: $0.003–0.005/request
- Coverage: Companies House lookup, officers, tech stack detection (55+ signatures), email patterns, domain enrichment

### Postcode & Address Lookup API
- URL: https://payapi.market/api/postcode-address-lookup-api
- Endpoints: 5 | Price: $0.001/request
- Coverage: UK postcode to coordinates, council, ward, constituency, address search, autocomplete

### Currency & Crypto API
- URL: https://payapi.market/api/currency-crypto-api
- Endpoints: 5 | Price: $0.001/request
- Coverage: ECB FX rates, conversion, historical back to 1999, CoinGecko crypto prices (batch up to 50)

### Screenshot & PDF Capture API
- URL: https://payapi.market/api/screenshot-pdf-capture-api
- Endpoints: 4 | Price: $0.002/request
- Coverage: Viewport screenshot, full-page screenshot, PDF render, element capture (Playwright + Chromium)

### DNS & Domain Intelligence API
- URL: https://payapi.market/api/dns-domain-intelligence-api
- Endpoints: 5 | Price: $0.002/request
- Coverage: All DNS record types, WHOIS, SSL certificate details, subdomain discovery via crt.sh, reverse-IP

### Web Scraper & Content Extractor API
- URL: https://payapi.market/api/web-scraper-content-extractor-api
- Endpoints: 4 | Price: $0.002/request
- Coverage: Clean text extraction (boilerplate stripped), links, metadata, structured data (tables, headings, images)

### IP Geolocation API
- URL: https://payapi.market/api/ip-geolocation-api
- Endpoints: 4 | Price: $0.001/request
- Coverage: Country, city, ISP, ASN, timezone, datacenter detection, batch lookup (20 IPs), distance between IPs

### QR Code API
- URL: https://payapi.market/api/qr-code-api
- Endpoints: 4 | Price: $0.001/request
- Coverage: Generate (custom colours, size, error correction), batch generation, decode QR codes from images

### UK HMO Licence API
- URL: https://payapi.market/api/uk-hmo-licence-api
- Endpoints: 3 | Price: $0.020–0.040/request
- Coverage: 124,715 licensed rental records across 65 UK councils (London, Edinburgh, Cardiff, major cities)

## Blog posts

- What is the x402 Protocol: https://payapi.market/blog/what-is-the-x402-protocol
- x402 vs API Keys vs OAuth: https://payapi.market/blog/x402-vs-api-keys-vs-oauth
- How to List Your API in 10 Minutes: https://payapi.market/blog/how-to-list-your-api-in-10-minutes
- AI Agent Economics 2026: https://payapi.market/blog/ai-agent-economics-2026
- PayAPI Market vs RapidAPI: https://payapi.market/blog/payapi-market-vs-rapidapi
- The Week PayAPI Market Started Telling the Truth: https://payapi.market/blog/the-week-payapi-started-telling-the-truth

## FAQ

**Q: What is x402?**
A: x402 revives HTTP 402 (Payment Required). Instead of API keys, the server responds with a signed payment requirement; the agent pays USDC on Base and retries. Under 1 second settlement, no account needed.

**Q: How much does it cost to list an API?**
A: Free. PayAPI Market takes a 3% fee on successful payments. Providers keep 97%. No monthly fee on the free tier.

**Q: What is the Featured tier?**
A: $49/month with a 2.5% platform fee, gold badge, always-first placement in search results, and priority in the MCP tool manifest.

**Q: Do AI agents need an API key?**
A: No. Agents make a request, receive HTTP 402, pay in USDC, and get the response. The wallet signature is the authentication.

**Q: What chain does payment settle on?**
A: USDC on Base. Under 1 second block finality.

**Q: How is PayAPI Market different from RapidAPI?**
A: RapidAPI uses API keys and monthly subscriptions for human developers. PayAPI Market uses x402 per-request USDC payments for AI agents. No keys, no minimums, no chargebacks. Providers keep 97% vs RapidAPI's ~80%.

## Founder

Chet Parker. Built and launched PayAPI Market in 2026. Background in UK property data. Built all 11 launch APIs.

## How AI agents connect

Add to Claude Desktop or any MCP-compatible client:
```json
{
  "mcpServers": {
    "payapi": {
      "url": "https://web-production-18a32.up.railway.app/mcp/sse"
    }
  }
}
```

After connecting, agents auto-discover every listed tool and can call any of them with x402 payments.

## Full content

Full crawlable content: https://payapi.market/llms-full.txt