Build software that pays its own way

Quickstart

Twenty minutes, one terminal and a browser wallet. By the end an agent you control has paid for a web search out of a budget you set, and you hold the receipt.

1. 1

   Install the SDK

   One package per language, all open source and all speaking the same wire format. The Node install also pulls in the buyer middleware, which turns a 402 response into a paid request. Pick your language above the code.

   NodePythonRustGoJava.NETSwift

   bashReady

   npm install @sidiora/layerx-sdk @sidiora/layerx-buyer-middleware

2. 2

   Connect to chain 125

   Paxeer X is an EVM chain, so MetaMask, PaxPort and any EIP-1193 wallet join it with the standard wallet_addEthereumChain call. Foundry, Hardhat, viem and ethers point at the same URL. Sixteen public nodes stand behind it.

   connect.tstypescriptReady

   1const PAXEER_X = {2  chainId: "0x7d", // 1253  chainName: "Paxeer X Network",4  nativeCurrency: { name: "Paxeer", symbol: "PAX", decimals: 18 },5  rpcUrls: ["https://api-mainnet-beta.paxeer.network/rpc"],6  blockExplorerUrls: ["https://paxscan.io"],7};89await window.ethereum.request({10  method: "wallet_addEthereumChain",11  params: [PAXEER_X],12});13const [address] = await window.ethereum.request({14  method: "eth_requestAccounts",15});

3. 3

   Give an agent a wallet with a limit

   An agent wallet is a wallet with rules attached. You name the agent, say what it is for, and set a monthly ceiling. The network holds the agent to that ceiling on every payment, so the agent never has to be trusted to stop on its own. Lower the limit later with agent.limit and it takes effect on the next request. Idempotency keys make every call safe to retry.

   agent.tstypescriptReady

   1import { ProductionClient, SecretBytes, idempotencyKey } from "@sidiora/layerx-sdk";2import { LayerXPaymentHttpTransport } from "@sidiora/layerx-buyer-middleware";34const layerx = new ProductionClient(5  new LayerXPaymentHttpTransport({6    baseUrl: process.env.LAYERX_API_URL,7    bearerToken: new SecretBytes(new TextEncoder().encode(process.env.LAYERX_API_TOKEN)),8  }),9);1011// A wallet for the agent, with a monthly ceiling the network enforces.12const journey = await layerx.human(13  "agent.create",14  {15    name: "research-bot",16    purpose: "Pays for search and inference",17    monthly_limit: { amount: "50", currency: "USD" },18  },19  { idempotencyKey: idempotencyKey("agent-create-research-bot") },20);2122// Change the ceiling any time. The agent cannot change it back.23await layerx.human(24  "agent.limit",25  { monthly_limit: { amount: "20", currency: "USD" } },26  { idempotencyKey: idempotencyKey("agent-limit-2026-10") },27);

4. 4

   Make one paid request

   Paid APIs on Paxeer X answer an unpaid call with HTTP 402 and a price. The buyer middleware reads the price, checks it against the agent's limit, pays, and repeats the request with proof attached. Your code sees one fetch. No API key to rotate, no card on file, no invoice at the end of the month.

   pay.tstypescriptReady

   1import { BuyerMiddleware } from "@sidiora/layerx-buyer-middleware";23const buyer = new BuyerMiddleware({4  client: layerx,5  source: agentAccount, // the wallet from step 36  supported: [{ scheme: "exact", network: "eip155:125" }],7  authorizedBatches, // receipt keys the SDK checks signatures against8});910// A normal fetch. If the server answers 402, the middleware pays11// within the agent's limit and retries with proof of payment.12const result = await buyer.fetch(13  "https://api.example.com/v1/search?q=paxeer",14  { method: "GET" },15  "search-2026-10-12-0001", // your idempotency key: pay once, never twice16);1718if (result.kind === "paid") {19  const data = await result.response.json();20}

5. 5

   Read the receipt

   Every payment comes back with a receipt signed by the network, in the same call, in milliseconds. The SDK verifies the signature before it hands the result to you, and the block that contains the payment is final within about a second. Keep the receipt bytes: anyone can check them later without trusting you or the server.

   receipt.tstypescriptReady

   1if (result.kind === "paid") {2  const { settlement, payment } = result;34  settlement.verification;     // the signature check the SDK already ran5  settlement.canonicalReceipt; // the receipt bytes, yours to keep or forward6  payment.quote.money;         // what the request cost7  payment.journey.state;       // "done" once the block is committed8}910// Anything that is not "paid" is a reason, never a silent failure.11// "refused" means a limit held; "pending" means the chain has it12// and the receipt is about to land.