Herald

notifykit

Unified notifications for Next.js. Any provider.

Send SMS, email, and push notifications through a single API. Provider-agnostic with adapters for Twilio, AWS SNS, Resend, and easy custom providers.

Install

npm install notifykit

Quick Start

import { createHerald } from "notifykit";
import { createTwilioProvider } from "notifykit/adapters/twilio";
import { createResendProvider } from "notifykit/adapters/resend";

const herald = createHerald({
  providers: [
    createTwilioProvider({
      accountSid: process.env.TWILIO_ACCOUNT_SID!,
      authToken: process.env.TWILIO_AUTH_TOKEN!,
      from: "+15551234567",
    }),
    createResendProvider({
      apiKey: process.env.RESEND_API_KEY!,
      from: "notifications@example.com",
    }),
  ],
});

// Send an SMS
await herald.send({
  to: "+15559876543",
  channel: "sms",
  body: "Your order has shipped!",
});

// Send an email
await herald.send({
  to: "user@example.com",
  channel: "email",
  subject: "Order Confirmation",
  body: "Thank you for your purchase.",
});

Providers

Twilio (SMS)

import { createTwilioProvider } from "notifykit/adapters/twilio";

const twilio = createTwilioProvider({
  accountSid: "AC...",
  authToken: "your-auth-token",
  from: "+15551234567",
});

Uses the Twilio REST API directly via fetch. No SDK dependency.

AWS SNS (Push)

import { SNSClient, PublishCommand } from "@aws-sdk/client-sns";
import { createSNSProvider } from "notifykit/adapters/sns";

const sns = createSNSProvider(
  { region: "us-east-1" },
  { SNSClient, PublishCommand },
);

You provide the AWS SDK classes. Herald stays lightweight.

Resend (Email)

import { createResendProvider } from "notifykit/adapters/resend";

const resend = createResendProvider({
  apiKey: "re_...",
  from: "notifications@example.com",
});

Uses the Resend REST API directly via fetch. No SDK dependency.

Custom Provider

import type { NotificationProvider } from "notifykit";

const myProvider: NotificationProvider = {
  channel: "sms",
  async send(notification) {
    // Your logic here
    return { success: true, channel: "sms", messageId: "abc" };
  },
};

Templates

Define templates with {{variable}} placeholders:

const herald = createHerald({
  providers: [twilio, resend],
  templates: {
    "order-shipped": {
      channel: "sms",
      body: "Hi {{name}}, your order #{{orderId}} has shipped!",
    },
    "welcome-email": {
      channel: "email",
      subject: "Welcome, {{name}}!",
      body: "Thanks for joining us, {{name}}. Get started at {{url}}.",
    },
  },
});

await herald.notify("order-shipped", {
  to: "+15559876543",
  data: { name: "Alice", orderId: "12345" },
});

React Hooks

import { HeraldProvider, useHerald, useNotification } from "notifykit/react";

function App() {
  return (
    
      
    
  );
}

function NotifyButton() {
  const { send, isSending } = useHerald();

  return (
    
        send({ to: "+15559876543", channel: "sms", body: "Hello!" })
      }
    >
      Send SMS
    
  );
}

function StatusAwareButton() {
  const { send, status, error } = useNotification();

  return (
    
      
          send({ to: "user@example.com", channel: "email", subject: "Hi", body: "Hello!" })
        }
      >
        Send
      
      {status === "sending" && Sending...}
      {status === "sent" && Sent!}
      {status === "error" && Error: {error}}
    
  );
}

Next.js API Routes

// app/api/notify/route.ts
import { createNotificationHandler } from "notifykit/next";
import { herald } from "@/lib/herald";

export const POST = createNotificationHandler(herald);

// app/api/webhooks/notifications/route.ts
import { createWebhookHandler } from "notifykit/next";

export const POST = createWebhookHandler({
  verify: (request, body) => {
    // Verify webhook signature
    return true;
  },
  onStatus: async (event) => {
    console.log(`Message ${event.messageId}: ${event.status}`);
  },
});

Building Custom Providers

Implement the NotificationProvider interface:

import type { NotificationProvider, Notification, SendResult } from "notifykit";

export function createMyProvider(config: MyConfig): NotificationProvider {
  return {
    channel: "sms", // or "email" or "push"
    async send(notification: Notification): Promise {
      // Send the notification using your service
      return {
        success: true,
        channel: "sms",
        messageId: "unique-id",
      };
    },
  };
}

License

MIT

Part of sathergate-toolkit

This package is part of the sathergate-toolkit — an agent-native infrastructure toolkit for Next.js. All packages work independently or together.

See Also

• shutterbox — Image processing pipeline (npm i shutterbox)
• flagpost — Feature flags with percentage rollouts (npm i flagpost)
• ratelimit-next — Rate limiting with sliding window & token bucket (npm i ratelimit-next)
• croncall — Serverless-native cron job scheduling (npm i croncall)
• vaultbox — AES-256-GCM encrypted secrets management (npm i vaultbox)
• searchcraft — Full-text search with BM25 scoring (npm i searchcraft)

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: sathergate
• Source: sathergate/herald
• License: MIT

Install and usage instructions live in the source repository linked above.