feat: add NWC sign message method

examples/nwc/client/sign-message.js

@@ -0,0 +1,27 @@
+import * as crypto from "node:crypto"; // required in node.js
+global.crypto = crypto; // required in node.js
+import "websocket-polyfill"; // required in node.js
+
+import * as readline from "node:readline/promises";
+import { stdin as input, stdout as output } from "node:process";
+
+import { nwc } from "../../../dist/index.module.js";
+
+const rl = readline.createInterface({ input, output });
+
+const nwcUrl =
+  process.env.NWC_URL ||
+  (await rl.question("Nostr Wallet Connect URL (nostr+walletconnect://...): "));
+
+rl.close();
+
+const client = new nwc.NWCClient({
+  nostrWalletConnectUrl: nwcUrl,
+});
+const response = await client.signMessage({
+  message: "Hello, world!",
+});
+
+console.info(response);
+
+client.close();

examples/nwc/sign-message.js

@@ -0,0 +1,26 @@
+import * as crypto from "node:crypto"; // required in node.js
+global.crypto = crypto; // required in node.js
+import "websocket-polyfill"; // required in node.js
+
+import * as readline from "node:readline/promises";
+import { stdin as input, stdout as output } from "node:process";
+
+import { webln as providers } from "../../dist/index.module.js";
+
+const rl = readline.createInterface({ input, output });
+
+const nwcUrl =
+  process.env.NWC_URL ||
+  (await rl.question("Nostr Wallet Connect URL (nostr+walletconnect://...): "));
+
+rl.close();
+
+const webln = new providers.NostrWebLNProvider({
+  nostrWalletConnectUrl: nwcUrl,
+});
+await webln.enable();
+const response = await webln.signMessage("Hello, world!");
+
+console.info(response);
+
+webln.close();

src/NWCClient.ts

@@ -28,7 +28,8 @@ type Nip47SingleMethod =
   | "pay_invoice"
   | "pay_keysend"
   | "lookup_invoice"
-  | "list_transactions";
+  | "list_transactions"
+  | "sign_message";
 
 type Nip47MultiMethod = "multi_pay_invoice" | "multi_pay_keysend";
 
@@ -128,6 +129,15 @@ export type Nip47LookupInvoiceRequest = {
   invoice?: string;
 };
 
+export type Nip47SignMessageRequest = {
+  message: string;
+};
+
+export type Nip47SignMessageResponse = {
+  message: string;
+  signature: string;
+};
+
 export interface NWCOptions {
   authorizationUrl?: string; // the URL to the NWC interface for the user to confirm the session
   relayUrl: string;
@@ -478,6 +488,22 @@ export class NWCClient {
       throw error;
     }
   }
+  async signMessage(
+    request: Nip47SignMessageRequest,
+  ): Promise<Nip47SignMessageResponse> {
+    try {
+      const result = await this.executeNip47Request<Nip47SignMessageResponse>(
+        "sign_message",
+        request,
+        (result) => result.message === request.message && !!result.signature,
+      );
+
+      return result;
+    } catch (error) {
+      console.error("Failed to request sign_message", error);
+      throw error;
+    }
+  }
 
   async multiPayInvoice(
     request: Nip47MultiPayInvoiceRequest,

src/webln/NostrWeblnProvider.ts

@@ -72,6 +72,7 @@ const nip47ToWeblnRequestMap: Record<Nip47Method, WebLNMethod> = {
   list_transactions: "listTransactions",
   multi_pay_invoice: "sendMultiPayment",
   multi_pay_keysend: "multiKeysend",
+  sign_message: "signMessage",
 };
 
 export class NostrWebLNProvider implements WebLNProvider, Nip07Provider {
@@ -292,7 +293,7 @@ export class NostrWebLNProvider implements WebLNProvider, Nip07Provider {
 
     const nip47Result = await this.client.payInvoice({ invoice });
 
-    const result = { preimage: nip47Result.preimage };
+    const result: SendPaymentResponse = { preimage: nip47Result.preimage };
     this.notify("sendPayment", result);
 
     return result;
@@ -312,11 +313,27 @@ export class NostrWebLNProvider implements WebLNProvider, Nip07Provider {
   async keysend(args: KeysendArgs): Promise<SendPaymentResponse> {
     await this.checkEnabled();
 
-    const nip47Result = await this.client.payKeysend(
+    const nip47Result: SendPaymentResponse = await this.client.payKeysend(
       mapKeysendToNip47Keysend(args),
     );
 
-    const result = { preimage: nip47Result.preimage };
+    const result: SendPaymentResponse = { preimage: nip47Result.preimage };
+    this.notify("keysend", result);
+
+    return result;
+  }
+
+  async signMessage(message: string): Promise<SignMessageResponse> {
+    await this.checkEnabled();
+
+    const nip47Result = await this.client.signMessage({
+      message,
+    });
+
+    const result: SignMessageResponse = {
+      message: nip47Result.message,
+      signature: nip47Result.signature,
+    };
     this.notify("keysend", result);
 
     return result;
@@ -343,7 +360,7 @@ export class NostrWebLNProvider implements WebLNProvider, Nip07Provider {
       //description_hash: "b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9"
     });
 
-    const result = { paymentRequest: nip47Result.invoice };
+    const result: MakeInvoiceResponse = { paymentRequest: nip47Result.invoice };
 
     this.notify("makeInvoice", result);
 
@@ -376,7 +393,7 @@ export class NostrWebLNProvider implements WebLNProvider, Nip07Provider {
 
     const nip47Result = await this.client.listTransactions(args);
 
-    const result = {
+    const result: ListTransactionsResponse = {
       transactions: nip47Result.transactions.map(
         mapNip47TransactionToTransaction,
       ),
@@ -460,9 +477,6 @@ export class NostrWebLNProvider implements WebLNProvider, Nip07Provider {
   request(method: WebLNRequestMethod, args?: unknown): Promise<unknown> {
     throw new Error("Method not implemented.");
   }
-  signMessage(message: string): Promise<SignMessageResponse> {
-    throw new Error("Method not implemented.");
-  }
   verifyMessage(signature: string, message: string): Promise<void> {
     throw new Error("Method not implemented.");
   }