feat: implement mpp draft spec

examples/mpp.js

@@ -0,0 +1,30 @@
+import { fetchWithMpp } from "../dist/esm/mpp.js";
+import { NWCClient } from "@getalby/sdk";
+
+const url = process.env.URL || "https://api.ppq.ai/v1/data/api/exa/answer";
+
+const nostrWalletConnectUrl = process.env.NWC_URL;
+
+if (!nostrWalletConnectUrl) {
+  throw new Error("Please set a NWC_URL env variable");
+}
+
+const nwc = new NWCClient({ nostrWalletConnectUrl });
+
+fetchWithMpp(
+  url,
+  {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify({ query: "What is the Lightning Network?" }),
+  },
+  { wallet: nwc },
+)
+  .then((response) => response.json())
+  .then((data) => {
+    console.info(JSON.stringify(data, null, 2));
+  })
+  .catch((err) => {
+    console.error("Error:", err.message);
+  })
+  .finally(() => nwc.close());

package.json

@@ -54,6 +54,11 @@
       "require": "./dist/cjs/x402.cjs",
       "types": "./dist/types/x402.d.ts"
     },
+    "./mpp": {
+      "import": "./dist/esm/mpp.js",
+      "require": "./dist/cjs/mpp.cjs",
+      "types": "./dist/types/mpp.d.ts"
+    },
     "./lnurl": {
       "import": "./dist/esm/lnurl.js",
       "require": "./dist/cjs/lnurl.cjs",

rollup.config.js

@@ -22,6 +22,7 @@ const entries = [
   { name: "402", input: "src/402/index.ts" },
   { name: "l402", input: "src/402/l402/index.ts" },
   { name: "x402", input: "src/402/x402/index.ts" },
+  { name: "mpp", input: "src/402/mpp/index.ts" },
   { name: "lnurl", input: "src/lnurl/index.ts" },
   { name: "podcasting2", input: "src/podcasting2/index.ts" },
 ];

src/402/fetch402.ts

@@ -1,6 +1,7 @@
 import { Wallet } from "./utils";
 import { handleL402Payment } from "./l402/l402";
 import { handleX402Payment } from "./x402/x402";
+import { handleMppChargePayment } from "./mpp/mpp";
 
 export const fetch402 = async (
   url: string,
@@ -20,9 +21,26 @@ export const fetch402 = async (
 
   const initResp = await fetch(url, fetchArgs);
 
-  const l402Header = initResp.headers.get("www-authenticate");
-  if (l402Header) {
-    return handleL402Payment(l402Header, url, fetchArgs, headers, wallet);
+  const wwwAuthHeader = initResp.headers.get("www-authenticate");
+  if (wwwAuthHeader) {
+    if (wwwAuthHeader.trimStart().toLowerCase().startsWith("payment")) {
+      return handleMppChargePayment(
+        wwwAuthHeader,
+        url,
+        fetchArgs,
+        headers,
+        wallet,
+      );
+    }
+    return handleL402Payment(
+      wwwAuthHeader,
+      url,
+      fetchArgs,
+      headers,
+      wallet,
+      store,
+      HEADER_KEY,
+    );
   }
 
   const x402Header = initResp.headers.get("PAYMENT-REQUIRED");

src/402/mpp/index.ts

@@ -0,0 +1,2 @@
+export * from "./mpp";
+export * from "./utils";