Nostr Signer Capacitor Plugin

This Capacitor plugin allows your application to interact with Nostr signer apps on the Android platform using intents, following the NIP-55 and NIP-07 specifications. It also provides web support by interacting with window.nostr for browser environments.

Install

npm install nostr-signer-capacitor-plugin
npx cap sync

Usage

Import the Plugin

import NostrSigner from 'nostr-signer-capacitor-plugin';

Set the Signer Package Name (Android Only)

Before using the plugin on Android, you need to set the package name of the external signer app.

await NostrSigner.setPackageName({ packageName: 'com.example.signer' });

Check if External Signer is Installed (Android Only)

const { installed } = await NostrSigner.isExternalSignerInstalled();
if (!installed) {
  console.log('External signer app is not installed.');
}

Get Public Key

try {
  const { npub } = await NostrSigner.getPublicKey();
  console.log('Public Key:', npub);
} catch (error) {
  console.error('Error getting public key:', error);
}

Sign Event

const event = {
  kind: 1,
  content: 'Hello, Nostr!',
  tags: [],
  created_at: Math.floor(Date.now() / 1000),
};

try {
  const { event: signedEventJson } = await NostrSigner.signEvent({
    eventJson: JSON.stringify(event),
  });
  const signedEvent = JSON.parse(signedEventJson);
  console.log('Signed Event:', signedEvent);
} catch (error) {
  console.error('Error signing event:', error);
}

NIP-04 Encrypt

try {
  const { result: encryptedText } = await NostrSigner.nip04Encrypt({
    pubKey: 'recipient_public_key',
    plainText: 'Secret message',
  });
  console.log('Encrypted Text:', encryptedText);
} catch (error) {
  console.error('Error encrypting message:', error);
}

NIP-04 Decrypt

try {
  const { result: decryptedText } = await NostrSigner.nip04Decrypt({
    pubKey: 'sender_public_key',
    encryptedText: 'encrypted_text',
  });
  console.log('Decrypted Text:', decryptedText);
} catch (error) {
  console.error('Error decrypting message:', error);
}

NIP-44 Encrypt

try {
  const { result: encryptedText } = await NostrSigner.nip44Encrypt({
    pubKey: 'recipient_public_key',
    plainText: 'Secret message',
  });
  console.log('Encrypted Text (NIP-44):', encryptedText);
} catch (error) {
  console.error('Error encrypting message (NIP-44):', error);
}

NIP-44 Decrypt

try {
  const { result: decryptedText } = await NostrSigner.nip44Decrypt({
    pubKey: 'sender_public_key',
    encryptedText: 'encrypted_text',
  });
  console.log('Decrypted Text (NIP-44):', decryptedText);
} catch (error) {
  console.error('Error decrypting message (NIP-44):', error);
}

Decrypt Zap Event

try {
  const { result: decryptedEventJson } = await NostrSigner.decryptZapEvent({
    eventJson: JSON.stringify(encryptedEvent),
  });
  const decryptedEvent = JSON.parse(decryptedEventJson);
  console.log('Decrypted Zap Event:', decryptedEvent);
} catch (error) {
  console.error('Error decrypting zap event:', error);
}

API

* [`setPackageName(...)`](#setpackagename) * [`isExternalSignerInstalled()`](#isexternalsignerinstalled) * [`getPublicKey()`](#getpublickey) * [`signEvent(...)`](#signevent) * [`nip04Encrypt(...)`](#nip04encrypt) * [`nip04Decrypt(...)`](#nip04decrypt) * [`nip44Encrypt(...)`](#nip44encrypt) * [`nip44Decrypt(...)`](#nip44decrypt) * [`decryptZapEvent(...)`](#decryptzapevent)

### setPackageName(...) ```typescript setPackageName(options: { packageName: string; }) => Promise ``` Sets the package name of the external Nostr signer app. This is required on Android to specify which app to interact with. | Param | Type | Description | | ------------- | ------------------------------------ | --------------------------------------------- | | **`options`** | { packageName: string; } | An object containing the package name string. | -------------------- ### isExternalSignerInstalled() ```typescript isExternalSignerInstalled() => Promise<{ installed: boolean; }> ``` Checks if the external Nostr signer app is installed on the device. **Returns:** Promise<{ installed: boolean; }> An object indicating whether the signer app is installed. -------------------- ### getPublicKey() ```typescript getPublicKey() => Promise<{ npub: string; }> ``` Requests the public key from the Nostr signer app or extension. **Returns:** Promise<{ npub: string; }> An object containing the public key in npub format. -------------------- ### signEvent(...) ```typescript signEvent(options: { eventJson: string; }) => Promise<{ event: string; }> ``` Requests the signer app to sign a Nostr event. | Param | Type | Description | | ------------- | ----------------------------------- | --------------------------------- | | **`options`** | { eventJson: string; } | An object containing the event in JSON string format. | **Returns:** Promise<{ event: string; }> An object containing the signed event in JSON string format. -------------------- ### nip04Encrypt(...) ```typescript nip04Encrypt(options: { plainText: string; pubKey: string; }) => Promise<{ result: string; }> ``` Encrypts a message using NIP-04 encryption. | Param | Type | Description | | ------------- | ----------------------------------------------------- | ------------------------------------------- | | **`options`** | { plainText: string; pubKey: string; } | An object containing the plaintext and the recipient's public key. | **Returns:** Promise<{ result: string; }> An object containing the encrypted text. -------------------- ### nip04Decrypt(...) ```typescript nip04Decrypt(options: { encryptedText: string; pubKey: string; }) => Promise<{ result: string; }> ``` Decrypts a message using NIP-04 decryption. | Param | Type | Description | | ------------- | ------------------------------------------------------- | ------------------------------------------- | | **`options`** | { encryptedText: string; pubKey: string; } | An object containing the encrypted text and the sender's public key. | **Returns:** Promise<{ result: string; }> An object containing the decrypted plaintext. -------------------- ### nip44Encrypt(...) ```typescript nip44Encrypt(options: { plainText: string; pubKey: string; }) => Promise<{ result: string; }> ``` Encrypts a message using NIP-44 encryption. | Param | Type | Description | | ------------- | ----------------------------------------------------- | ------------------------------------------- | | **`options`** | { plainText: string; pubKey: string; } | An object containing the plaintext and the recipient's public key. | **Returns:** Promise<{ result: string; }> An object containing the encrypted text. -------------------- ### nip44Decrypt(...) ```typescript nip44Decrypt(options: { encryptedText: string; pubKey: string; }) => Promise<{ result: string; }> ``` Decrypts a message using NIP-44 decryption. | Param | Type | Description | | ------------- | ------------------------------------------------------- | ------------------------------------------- | | **`options`** | { encryptedText: string; pubKey: string; } | An object containing the encrypted text and the sender's public key. | **Returns:** Promise<{ result: string; }> An object containing the decrypted plaintext. -------------------- ### decryptZapEvent(...) ```typescript decryptZapEvent(options: { eventJson: string; }) => Promise<{ result: string; }> ``` Decrypts a zap event. | Param | Type | Description | | ------------- | ----------------------------------- | --------------------------------- | | **`options`** | { eventJson: string; } | An object containing the encrypted zap event in JSON string format. | **Returns:** Promise<{ result: string; }> An object containing the decrypted zap event in JSON string format. --------------------

Notes

On Android, the plugin communicates with external signer apps using intents as per NIP-55.
On Web, the plugin uses window.nostr to interact with Nostr browser extensions as per NIP-07.
Ensure that the external signer app or browser extension supports the required NIP specifications.

License

MIT License

chebizarro / nostr-signer-capacitor-plugin

readme