Next Act x402 Quickstart

Next Act supports autonomous license purchases through x402 v2 on Solana.

How the flow works

text

Agent
  ↓ POST /v1/agent-licenses
Next Act
  ↓ 402 + PAYMENT-REQUIRED
x402 client
  ↓ signs Solana payment
Next Act / facilitator
  ↓ verifies + settles
Next Act
  ↓ issues LIC-...
Agent
  ← 201 + PAYMENT-RESPONSE

Prerequisites

You need:

Node.js 20+
a Next Act API key with licenses:write
a throwaway Solana devnet wallet
enough devnet USDC for the license
enough devnet SOL for transaction fees if required by the client flow
access to the Next Act API at https://nextact.fun

Create a test project

powershell

cd C:\Users\YOU\Downloads
mkdir next-act-x402-test
cd next-act-x402-test
npm init -y

Install dependencies

The tested package set is:

powershell

npm install @x402/core@2.19.0 @x402/svm@2.19.0 @x402/fetch @solana/kit @scure/base

Create the buyer script

Create the file:

powershell

New-Item -ItemType File -Name "test-x402.mjs"

Copy examples/x402-buyer.mjs from this documentation bundle into that file.

The buyer should target:

text

https://nextact.fun/v1/agent-licenses

For local development, use:

text

http://localhost:3000/v1/agent-licenses

Set environment variables

powershell

$env:NEXT_ACT_API_KEY = "vos_live_YOUR_TEST_KEY"
$env:SVM_PRIVATE_KEY = "YOUR_THROWAWAY_DEVNET_BASE58_SECRET_KEY"

Run the purchase

powershell

node test-x402.mjs

The client will:

POST the right ID to Next Act.
Receive 402 Payment Required.
Decode PAYMENT-REQUIRED.
Create and sign the Solana payment.
Retry the same request automatically.
Receive the issued Next Act license.

Tested result

A successful private-beta devnet test returned:

HTTP status: 201

with a response shaped like:

json

{
  "object": "agent_license",
  "x402": true,
  "quote_id": "XQ-A9B77CB8E9D7",
  "payment": {
    "status": "settled",
    "network": "solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1",
    "transaction": "SOLANA_TRANSACTION_SIGNATURE"
  },
  "license": {
    "public_id": "LIC-...",
    "status": "active"
  },
  "already_fulfilled": false
}

The x402 settlement response also confirms the payer, Solana transaction, and devnet network.

x402 quote semantics

Each purchase request requires a unique Idempotency-Key.

The persisted quote binds:

right
asset
price
creator payout wallet
license terms
network
x402 payment requirements

Normal retry behavior reuses the stored quote rather than creating a second purchase.

Quote state:

text

pending -> settled -> fulfilled

Current x402 fee policy

Next Act's standard checkout applies:

text

Gross license price
      ↓
2.5% Next Act platform fee
      ↓
97.5% net proceeds
      ↓
configured creator / collaborator revenue split

The current x402 devnet MVP is different.

It uses a single payTo recipient and sends the full license price directly to the creator payout wallet. It does not collect the normal Next Act 2.5% platform fee and does not currently execute the generalized multi-recipient collaborator split used by standard checkout.

Private-beta limitations

The current x402 path is intentionally narrow:

Solana devnet only
single payTo recipient
no Next Act platform fee
no generalized collaborator revenue split
external settlement occurs before final database fulfillment, so a crash window still exists between those steps
the same Idempotency-Key should be reused to recover a settled quote if fulfillment fails

For the complete standard checkout flow, read the SDK Quickstart.

For the fastest working agent example, read Buy a Next Act License in 5 Minutes.

Before V1 freeze, the main x402 product decision is the production payout model: how Next Act should collect its platform fee while supporting creator and collaborator payouts in an agent-native payment flow.