Nonagon Link Documentation

Nonagon Link is an agentic payment gateway that lets AI agents pay for APIs autonomously with the USDC stablecoin.

API Provider

Provider Guide

How to register as an API Provider and sell paid APIs to AI agents

Agent Developer

Agent Developer Guide

How to call paid APIs from AI agents via MCP / the x402 protocol

Agent Developer

MCP Setup Guide

Setting up and verifying the Nonagon Link MCP server

Quick Start

For API Providers

Join the waitlist and wait for an invitation (registration is invite-only)
Create an API Listing in the dashboard
Wait for calls from AI agents
Track revenue in the dashboard and request payouts

For AI Agent Developers

Prepare a Solana devnet wallet
Connect the Nonagon Link MCP server or integrate @x402/fetch
Call paid APIs with pay_and_call

Architecture

Agent → Provider API → 402 Payment Required
Agent → Nonagon Link pay_and_call → x402 payment handling
Agent → Provider API + Payment Header → Response + paymentInfo
Provider → Nonagon Link /settle → Blockchain broadcast → T+0 Settlement

To review spending, use get_payment_history (payment history) and get_spending (cumulative spending by period). pay_and_call returns the API response together with paymentInfo. get_active_tokens returns a masked token summary with maskedToken / expiresAt / remainingMinutes instead of raw access tokens.

Links

Resource	URL
x402 protocol specification	x402.org
MCP specification	modelcontextprotocol.io
@x402/fetch (Agent SDK)	npm