Verified against @dexterai/x402 5.3.1 · 2026-07-07
Start here
By the end of this page you will know which section to open first. There are two ways in: you write code, or you drive an AI client that does the work for you. Pick the one that matches what you are trying to do.
Do you write code?
If you are integrating payments into your own program, you are on the developer path. Install the SDK and either pay for x402 endpoints or put a paywall on your own API.
If you want an agent to find and pay for APIs on your behalf without touching a codebase, you are on the operator path. Install OpenDexter into an AI client once, then ask it in plain language.
Developer
Install the buyer SDK:
Then pick your journey.
Pay for APIs
Call an x402 endpoint and pay per request. Browser wallet in a web app, or a keypair in a Node script.
Get paid
Put an x402 paywall on your own API and settle what buyers owe you.
Where to start inside the buyer path:
Pay from a browser wallet
A user signs each payment with Phantom or another connected wallet.
Pay from a Node agent
A process pays on its own with a keypair. Includes funding the wallet with USDC.
Cap spend
Bound how much a wallet can spend before it stops paying.
Handle errors safely
Which failures are safe to retry and which can pay twice if you retry them.
Paying for many calls to the same seller? Open a tab once instead of a fresh transaction per call. Start at What is a tab.
Operator
You do not write any code. You install OpenDexter into your AI client (Claude Code, Cursor, Codex, and others), fund a local wallet with USDC, and then ask your agent to find, price-check, and pay for APIs.
Install into the client the command detects:
The installer creates a Solana and an EVM wallet at ~/.dexterai-mcp/wallet.json and prints both addresses. Fund either one with USDC. After that your agent can search the marketplace and pay from your machine.
Add sign-in or read the vault engine
Adding Dexter accounts to a frontend, or working with the vault directly, sits outside the pay and get-paid flows.
Sign in with Dexter
Drop the @dexterai/connect sign-in component into a web app.
Vault engine reference
The engine under tabs and spending caps. Read this when you need the low-level contract, not the front door.
New to the terms used across these pages? The glossary defines tab, vault, spend grant, and the rest.