# CronSynth - Externalized Cron for Autonomous Agents

## What is CronSynth?

CronSynth provides scheduled webhook triggers for AI agents running in serverless environments. Agents register a cron expression and webhook URL; CronSynth triggers the webhook on schedule.

## Why use CronSynth?

Serverless agents can't run background timers. CronSynth centralizes scheduling so agents get time-awareness as a service.

## Quick Start

1. Create an x402 payment session via Coinbase CDP (https://docs.cdp.coinbase.com/x402)
   - NOTE: x402 is Coinbase's payment protocol (HTTP 402), separate from ETHYS
2. POST to https://cronsynth.xyz/api/schedule with your webhook and cron expression
3. Receive HMAC-signed triggers at your webhook on schedule

## API Endpoints

POST /api/schedule     - Register a new schedule
POST /api/unschedule   - Remove a schedule  
GET  /api/schedules    - List your schedules
GET  /api/health       - Service status

## Authentication

All requests require an X-402-Session header with a valid payment session.

## Webhook Payload

{
  "scheduleId": "sch_abc123",
  "timestamp": 1701433200,
  "runNumber": 48,
  "cron": "*/5 * * * *"
}

Verify via X-CronSynth-Signature header using HMAC-SHA256.

## Pricing

Free tier: 1 schedule, unlimited triggers
Pay-per-trigger: $0.001 USDC per trigger
Subscriptions available at hourly/weekly/monthly rates

## Integration

- Works with any HTTPS endpoint
- 5-second webhook timeout (acknowledge fast, process async)
- Automatic retry with exponential backoff
- On-chain attestation available for reputation

## Complete API Documentation

For comprehensive API documentation, see:
- /ai.txt - AI agent discovery file with explicit instructions (START HERE)
- /ai-api-guide.txt - Complete plain text API guide for AI agents (READ THIS FIRST)
- /.well-known/openapi.json - OpenAPI specification
- /.well-known/ai-plugin.json - AI plugin manifest
- /docs - Human-readable user guide

## Discovery Files

- /.well-known/agents.json - Agent service discovery
- /.well-known/agent-card.json - ETHYS agent card
- /.well-known/x402.json - x402 protocol configuration
- /robots.txt - Web crawler instructions
- /sitemap.xml - Site structure

## Related Services

- BlockWire (https://blockwire.xyz) - Real-time blockchain events
- ETHYS (https://ethys.dev) - Agent discovery and registration (separate from x402 payments)
- Coinbase CDP x402 (https://docs.cdp.coinbase.com/x402) - Payment protocol (HTTP 402)