lightning-mpp-extension-sdk

Automatically routes 402 Payment Required approvals through a compatible browser extension via a window event bridge.

When a server responds with a 402 Lightning payment challenge, the SDK:

1. Probes the page for a compatible extension using the mpp:extension event (type: 'request', paymentMethods: ['lightning'], intents: ['charge']).
2. Forwards the Lightning Payment challenge to the extension via mpp:challenge.
3. Waits for the extension's mpp:credential response and transparently retries the original request with the returned credential.

Installation

npm install lightning-mpp-extension-sdk

Usage

import { createLightningMppExtensionClient } from 'lightning-mpp-extension-sdk';

const client = createLightningMppExtensionClient({
  polyfill: false,
});

const response = await client.fetch('https://api.example.com/paid-endpoint');
const data = await response.json();

Options

interface CreateLightningMppExtensionClientOptions {
  /** Custom fetch implementation. Defaults to the global fetch. */
  fetch?: typeof globalThis.fetch;
  /** Patch the global fetch (Mppx.create polyfill). Defaults to true. */
  polyfill?: boolean;
  /** Timeout for the extension payment approval, in ms. Defaults to 90000. */
  paymentTimeoutMs?: number;
  /** Probe for the extension before requesting credentials. Defaults to true. */
  probeExtension?: boolean;
  /** Timeout for the extension probe, in ms. Defaults to 1500. */
  extensionProbeTimeoutMs?: number;
}

Restoring global fetch

If you used the global fetch polyfill, restore the original implementation with:

import { restoreLightningMppExtensionFetch } from 'lightning-mpp-extension-sdk';

restoreLightningMppExtensionFetch();

Requirements

• A browser window context (the SDK throws if window is unavailable).
• A compatible extension installed on the page that responds to the mpp:extension, mpp:challenge, and mpp:credential events.

Development

npm install      # install dependencies + dev dependencies
npm run build    # bundle ESM + CJS + type declarations into dist/

License

MIT