402-indexer

Nostr: npub1mgvlrnf5hm9yf0n5mf9nqmvarhvxkc6remu5ec3vf8r0txqkuk7su0e7q2

Nostr-native crawler that discovers L402 and x402 paid APIs and publishes kind 31402 events for decentralised service discovery.

What it does

The indexer finds paid APIs across multiple channels and announces them on Nostr so clients like 402-mcp and the 402.pub directory can discover them.

Discovery channels

• Active prober — HTTP probe for WWW-Authenticate: L402 and 402 Payment Required headers
• Nostr aggregator — Subscribe to existing kind 31402 events across relays
• GitHub scanner — Search GitHub for repos using L402/x402 patterns
• npm scanner — Find packages depending on toll-booth, aperture, and other L402 libraries
• Community listener — Accept kind 1402 suggestion events from users

Health monitoring

Discovered services are verified daily. Endpoints that become unreachable are marked stale and eventually delisted, keeping the directory accurate.

Usage

# Install
npm install

# Configure (see config section below)
cp config/default.json config/local.json

# Build and run
npm run build
npm start

Configuration

The indexer reads from config/local.json and environment variables:

• NOSTR_NSEC — Nostr secret key for signing kind 31402 events
• RELAYS — Comma-separated relay URLs

Part of the 402 ecosystem

Package	Purpose
toll-booth	L402 middleware — gate any API behind Lightning
402-announce	Publish kind 31402 service announcements
402-mcp	AI agents discover, pay for, and consume 402 APIs
402.pub	Live service directory
402-indexer	Crawl and index paid APIs (this repo)

Licence

MIT