Thousands of payments.
One transaction.

Your AI agent needs to pay for APIs, tools, and compute. Fund it once — it pays for everything automatically. Services verify payment instantly. You stay in control.

Use with agents Accept agent payments

my-agent

Integration

import { SpxClient } from "@spx/sdk/agent";

// Fund your agent once, it pays for everything
const spx = new SpxClient({ agentKey, fundingSource });

// Every API call — instant, free, no transaction
const { header } = spx.pay(service, price);
await fetch(url, { headers: { "X-Payment": header } });

How it works

Fund your agent

Deposit USDC and set a spending limit. Your agent gets its own payment key — it can spend, but never withdraw.

Agent pays automatically

Every API call, your agent authorizes payment instantly — no blockchain transaction, no delay. Services verify in microseconds and respond immediately.

Services collect

When a service is ready to cash out, it submits one transaction — no matter how many calls your agent made. 10,000 payments, 1 settlement.

The problem today

Without SPX

Every API call is a separate blockchain transaction
10,000 calls = 10,000 transactions = ~$2.50 in fees
400ms+ latency added to every request
No spending limits — agent can drain the wallet
Separate setup for every vendor

With SPX

Payments happen off-chain — free and instant
10,000 calls = 1 transaction = $0.00025
Under 1ms per payment — no added latency
Hard spending cap enforced on-chain
One funding source, unlimited services

<1ms

per payment

per API call

1 tx

to settle all payments

0.5%

on settlement only

Compatible with

x402

x402 tells the agent "this costs money." SPX is how it pays — instantly, off-chain, no transaction per call.

Learn more →

Compatible with

MPP

MPP coordinates the payment session. SPX settles it — orders of magnitude cheaper than card rails for agent-to-service payments.