nBridge

🌉

One API, four transports

Android JavascriptInterface, iOS WKWebView message handlers, iframe postMessage, and a web loopback for local dev — auto-detected at runtime.

🛡️

Bring your own validator

Standard Schema support means zod 3.24+/4, valibot, or ArkType just work — or skip validation entirely. Zero forced dependencies.

⚡

Promise-based request/response

sendWithResponse() correlates replies by message id, with per-call timeouts. No callback spaghetti across the native boundary.

🤝

A handshake that means it

Opt-in handshake protocol — isReady() reflects that the other side actually answered, not just that your JavaScript loaded.

🧅

Middleware, both directions

An onion-model pipeline for outgoing and incoming messages, plus ten built-ins — logging, retry, throttle, encryption, and more.

📦

Batching, compression, retry queue

Opt-in message batching, deflate compression above a size threshold, and a priority queue that parks undelivered sends and replays them automatically.

🎛️

Host Rules

Map (platform, version) to named capabilities and variants in one config file, then ask host.supports("nativeShare") instead of scattering platform checks. Synchronous, no network, safe to import on the server.

⚛️

React, Next.js, DevTools

Typed hooks via nbridge/react, WebView back-navigation via nbridge/next, and an in-page DevTools panel via nbridge/devtools.

📊

Live metrics

Messages per second, success rate, average response time, bytes over the wire — collected in-process and streamed to listeners.

Show me code

Define messages once, get typed payloads and responses everywhere — with the validator you already use, or none at all.

zodvalibotno validator

import { z } from "zod";
import { createBridge, defineMessage } from "nbridge";

const schemas = {
  getUser: defineMessage({
    type: "getUser",
    payloadSchema: z.object({ id: z.string() }),
    responseSchema: z.object({ name: z.string(), email: z.string() }),
  }),
};

const bridge = createBridge({ schemas });

// Typed + validated at runtime
const user = await bridge.sendWithResponse("getUser", { id: "42" });
console.log(user.name);

import * as v from "valibot";
import { createBridge, defineMessage } from "nbridge";

const schemas = {
  getUser: defineMessage({
    type: "getUser",
    payloadSchema: v.object({ id: v.string() }),
    responseSchema: v.object({ name: v.string(), email: v.string() }),
  }),
};

const bridge = createBridge({ schemas });

const user = await bridge.sendWithResponse("getUser", { id: "42" });
console.log(user.name);

import { createBridge } from "nbridge";

const bridge = createBridge();

// Fire-and-forget
await bridge.send("analytics", { event: "page_view" });

// Request/response, correlated by message id
const user = await bridge.sendWithResponse<
  { id: string },
  { name: string; email: string }
>("getUser", { id: "42" });

// Listen for messages from the host
bridge.on("themeChanged", (payload) => {
  console.log("Native says:", payload);
});

nBridgeOne bridge between your web app and every host