Bridge API

bridge and PWABridge are the low-level transport for native module calls.

Core methods

Method	Description
isAvailable()	Checks window.webkit.messageHandlers.pwakit
initialize()	Installs window.pwakit._handleResponse/_handleEvent handlers
call(module, action, payload?, options?)	Sends request to native and resolves with response data
on(type, listener)	Subscribes to pwa:<type> CustomEvents
once(type, listener)	One-time event listener

Basic call

import { bridge } from "@pwa-kit/sdk";

const result = await bridge.call<{ message: string }>(
  "helloWorld",
  "greet",
  { name: "Taylor" }
);

Timeout control

Default timeout is 30000 ms.

await bridge.call(
  "healthkit",
  "queryStepCount",
  {
    startDate: "2026-03-01T00:00:00Z",
    endDate: "2026-03-02T00:00:00Z"
  },
  { timeout: 45000 }
);

Message and response shape

interface BridgeMessage {
  id: string;
  module: string;
  action: string;
  payload?: unknown;
}

interface BridgeResponse<T = unknown> {
  id: string;
  success: boolean;
  data?: T;
  error?: string;
}

Events

Native events are dispatched as browser events with pwa: prefix.

import { bridge } from "@pwa-kit/sdk";

const unsubscribe = bridge.on<{ title?: string }>("push", (data) => {
  console.log(data.title);
});

// Later
unsubscribe();

Equivalent direct listener:

window.addEventListener("pwa:push", (event) => {
  console.log((event as CustomEvent).detail);
});

Error types

• BridgeUnavailableError: bridge not present
• BridgeTimeoutError: call exceeded timeout
• BridgeError: native returned an error (or send failed)

See Error Handling for patterns.