Skip to content
Unibase Docs

Unibase Pay Quick Start

Use the x402 API to verify and settle payments in 5 minutes.

1. API Base URL

Section titled “1. API Base URL”
https://api.x402.unibase.com/v2

2. Supported Networks

Section titled “2. Supported Networks”
Network CAIP-2
BNB Smart Chain eip155:56
BSC Testnet eip155:97
Base eip155:8453
Base Sepolia eip155:84532
Polygon eip155:137
Arbitrum One eip155:42161

3. First call

Section titled “3. First call”

GET /supported needs no auth and no payload, so it is both the liveness check and the source of truth for what the facilitator accepts. There is no /health endpoint.

Terminal window
curl https://api.x402.unibase.com/v2/supported

4. Endpoints

Section titled “4. Endpoints”
Method Endpoint Description
POST /verify Check a payment payload without settling it
POST /settle Settle a payment on-chain
GET /supported Scheme and network pairs served

/verify and /settle are POST only — a GET returns 405.

5. Payment Schemes

Section titled “5. Payment Schemes”
  • exact — fixed, known amount
  • upto — authorize a ceiling, settle actual usage (metered billing)
  • batch-settlement — many micropayments in one on-chain transaction

6. Protocol Reference

Section titled “6. Protocol Reference”

See x402.org for the full protocol specification. Servers declare payment requirements; clients send signed payloads; facilitators verify and settle on-chain.

Next Steps

Section titled “Next Steps”