Building X402 Resources
This guide is for developers who want to build X402-compatible resources that work seamlessly with x402.jobs workflows.
What is an X402 Resource?
An X402 resource is an HTTP endpoint that implements the X402 payment protocol. When a client makes a request, the server responds with a 402 Payment Required status, the client pays, and then receives the actual response.
Integration with x402.jobs
When you register your resource on x402.jobs, users can:
- Discover your resource in the marketplace
- Add it to their workflows
- Chain it with other resources
- Run automated jobs that call your resource
Key Concepts
1. The 402 Response
Your endpoint should return a 402 Payment Required response with payment details:
{
"x402Version": 1,
"accepts": [{
"scheme": "exact",
"network": "solana",
"maxAmountRequired": "50000",
"resource": "https://api.example.com/generate",
"payTo": "YourWalletAddress...",
"asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
"outputSchema": {
"input": { ... },
"output": { ... }
}
}]
}
2. Synchronous vs Asynchronous
Resources can be:
- Synchronous: Return the result immediately after payment
- Asynchronous (LRO): Return a status URL to poll for the result
For operations that take more than a few seconds (AI generation, media processing, etc.), use the Long Running Operations pattern.
3. Output Schema
Define your input fields and output structure in the outputSchema so x402.jobs can:
- Generate forms for user input
- Display results properly
- Enable field mapping between nodes
Next Steps
- Long Running Operations - Handle async operations
- Output Schema - Define your API contract
- Best Practices - Tips for building reliable resources