Update examples for clients (axios,fetch) and servers(express) to support Stellar

Author: marcelosalloum

examples/typescript/clients/axios/.env-local

@@ -1,3 +1,4 @@
 RESOURCE_SERVER_URL=http://localhost:4021
 ENDPOINT_PATH=/weather
+NETWORK=base-sepolia
 PRIVATE_KEY=

examples/typescript/clients/axios/index.ts

@@ -4,6 +4,7 @@ import { withPaymentInterceptor, decodeXPaymentResponse, createSigner, type Hex
 
 config();
 
+const network = (process.env.NETWORK || "base-sepolia") as string; // e.g. base-sepolia, or solana-devnet, or stellar-testnet
 const privateKey = process.env.PRIVATE_KEY as Hex | string;
 const baseURL = process.env.RESOURCE_SERVER_URL as string; // e.g. https://example.com
 const endpointPath = process.env.ENDPOINT_PATH as string; // e.g. /weather
@@ -20,11 +21,11 @@ if (!baseURL || !privateKey || !endpointPath) {
  * - PRIVATE_KEY: The private key of the signer
  * - RESOURCE_SERVER_URL: The URL of the resource server
  * - ENDPOINT_PATH: The path of the endpoint to call on the resource server
+ * - NETWORK: The network to use for the signer (e.g. base-sepolia, solana-devnet, stellar-testnet)
  *
  */
 async function main(): Promise<void> {
-  // const signer = await createSigner("solana-devnet", privateKey); // uncomment for solana
-  const signer = await createSigner("base-sepolia", privateKey);
+  const signer = await createSigner(network, privateKey);
 
   const api = withPaymentInterceptor(
     axios.create({

examples/typescript/clients/fetch/.env-local

@@ -1,3 +1,4 @@
 RESOURCE_SERVER_URL=http://localhost:4021
 ENDPOINT_PATH=/weather
+NETWORK=base-sepolia
 PRIVATE_KEY=

examples/typescript/clients/fetch/index.ts

@@ -3,6 +3,7 @@ import { decodeXPaymentResponse, wrapFetchWithPayment, createSigner, type Hex }
 
 config();
 
+const network = (process.env.NETWORK || "base-sepolia") as string; // e.g. base-sepolia, or solana-devnet, or stellar-testnet
 const privateKey = process.env.PRIVATE_KEY as Hex | string;
 const baseURL = process.env.RESOURCE_SERVER_URL as string; // e.g. https://example.com
 const endpointPath = process.env.ENDPOINT_PATH as string; // e.g. /weather
@@ -20,10 +21,11 @@ if (!baseURL || !privateKey || !endpointPath) {
  * - PRIVATE_KEY: The private key of the signer
  * - RESOURCE_SERVER_URL: The URL of the resource server
  * - ENDPOINT_PATH: The path of the endpoint to call on the resource server
+ * - NETWORK: The network to use for the signer (e.g. base-sepolia, solana-devnet, stellar-testnet)
+ *
  */
 async function main(): Promise<void> {
-  // const signer = await createSigner("solana-devnet", privateKey); // uncomment for solana
-  const signer = await createSigner("base-sepolia", privateKey);
+  const signer = await createSigner(network, privateKey);
   const fetchWithPayment = wrapFetchWithPayment(fetch, signer);
 
   const response = await fetchWithPayment(url, { method: "GET" });

examples/typescript/facilitator/.env-local

@@ -1,3 +1,4 @@
 EVM_PRIVATE_KEY=0xYourPrivateKey
 SVM_PRIVATE_KEY=base58EncodedSolanaPrivateKey
+STELLAR_PRIVATE_KEY=base32EncodedStellarPrivateKey
 PORT=3002

examples/typescript/facilitator/README.md

@@ -44,6 +44,7 @@ cd facilitator
 ```env
 EVM_PRIVATE_KEY=0xYourPrivateKey
 SVM_PRIVATE_KEY=base58EncodedSolanaPrivateKey
+STELLAR_PRIVATE_KEY=base32EncodedStellarPrivateKey
 ```
 
 3. Start the server:

examples/typescript/facilitator/index.ts

@@ -16,23 +16,31 @@ import {
   SupportedPaymentKind,
   isSvmSignerWallet,
   type X402Config,
+  SupportedStellarNetworks,
+  StellarConnectedClient,
 } from "x402/types";
 
 config();
 
 const EVM_PRIVATE_KEY = process.env.EVM_PRIVATE_KEY || "";
 const SVM_PRIVATE_KEY = process.env.SVM_PRIVATE_KEY || "";
 const SVM_RPC_URL = process.env.SVM_RPC_URL || "";
+const STELLAR_PRIVATE_KEY = process.env.STELLAR_PRIVATE_KEY || "";
+const STELLAR_RPC_URL = process.env.STELLAR_RPC_URL || "";
 
-if (!EVM_PRIVATE_KEY && !SVM_PRIVATE_KEY) {
+if (!EVM_PRIVATE_KEY && !SVM_PRIVATE_KEY && !STELLAR_PRIVATE_KEY) {
   console.error("Missing required environment variables");
   process.exit(1);
 }
 
 // Create X402 config with custom RPC URL if provided
-const x402Config: X402Config | undefined = SVM_RPC_URL
-  ? { svmConfig: { rpcUrl: SVM_RPC_URL } }
-  : undefined;
+const x402Config: X402Config | undefined =
+  SVM_RPC_URL || STELLAR_RPC_URL
+    ? {
+        svmConfig: { rpcUrl: SVM_RPC_URL },
+        stellarConfig: { rpcUrl: STELLAR_RPC_URL },
+      }
+    : undefined;
 
 const app = express();
 
@@ -73,6 +81,8 @@ app.post("/verify", async (req: Request, res: Response) => {
       client = createConnectedClient(paymentRequirements.network);
     } else if (SupportedSVMNetworks.includes(paymentRequirements.network)) {
       client = await createSigner(paymentRequirements.network, SVM_PRIVATE_KEY);
+    } else if (SupportedStellarNetworks.includes(paymentRequirements.network)) {
+      client = await createSigner(paymentRequirements.network, STELLAR_PRIVATE_KEY);
     } else {
       throw new Error("Invalid network");
     }
@@ -123,6 +133,22 @@ app.get("/supported", async (req: Request, res: Response) => {
       },
     });
   }
+
+  // stellar
+  if (STELLAR_PRIVATE_KEY) {
+    const client = createConnectedClient("stellar-testnet", x402Config) as StellarConnectedClient;
+    const latestLedgerNumber = (await client.getLatestLedger()).sequence;
+
+    kinds.push({
+      x402Version: 1,
+      scheme: "exact",
+      network: "stellar-testnet",
+      extra: {
+        maxLedger: latestLedgerNumber + 12,
+      },
+    });
+  }
+
   res.json({
     kinds,
   });
@@ -140,6 +166,8 @@ app.post("/settle", async (req: Request, res: Response) => {
       signer = await createSigner(paymentRequirements.network, EVM_PRIVATE_KEY);
     } else if (SupportedSVMNetworks.includes(paymentRequirements.network)) {
       signer = await createSigner(paymentRequirements.network, SVM_PRIVATE_KEY);
+    } else if (SupportedStellarNetworks.includes(paymentRequirements.network)) {
+      signer = await createSigner(paymentRequirements.network, STELLAR_PRIVATE_KEY);
     } else {
       throw new Error("Invalid network");
     }

examples/typescript/servers/express/index.ts

@@ -1,8 +1,9 @@
 import { config } from "dotenv";
 import express from "express";
-import { paymentMiddleware, Resource, type SolanaAddress } from "x402-express";
+import { Network, paymentMiddleware, Resource, type SolanaAddress } from "x402-express";
 config();
 
+const network = (process.env.NETWORK || "base-sepolia") as Network;
 const facilitatorUrl = process.env.FACILITATOR_URL as Resource;
 const payTo = process.env.ADDRESS as `0x${string}` | SolanaAddress;
 
@@ -20,9 +21,7 @@ app.use(
       "GET /weather": {
         // USDC amount in dollars
         price: "$0.001",
-        // network: "base" // uncomment for Base mainnet
-        // network: "solana" // uncomment for Solana mainnet
-        network: "base-sepolia",
+        network,
       },
       "/premium/*": {
         // Define atomic amounts in any EIP-3009 token
@@ -38,9 +37,7 @@ app.use(
             },
           },
         },
-        // network: "base" // uncomment for Base mainnet
-        // network: "solana" // uncomment for Solana mainnet
-        network: "base-sepolia",
+        network,
       },
     },
     {