@avalanche-sdk/webhooks

@avalanche-sdk/webhooks

The Avalanche Webhooks SDK is a powerful and flexible toolset designed to simplify the integration with Avalanche's suite of blockchain services.

Currently, this SDK is focused on providing robust support for Webhooks APIs.

Summary

Webhooks API: Webhooks API enables real-time monitoring of on-chain events across the Avalanche C-chain, subnets, and L1 networks. It provides instant notifications for activities like smart contract events, NFT transfers, and wallet transactions. Developers can customize filters to track specific events and verify notifications using shared secrets for security

Table of Contents

• SDK Installation
• Requirements
• SDK Example Usage
• Authentication
• Available Resources and Operations
• Standalone functions
• Pagination
• Retries
• Error Handling
• Server Selection
• Custom HTTP Client
• Debugging
• Development
  • Maturity
  • Contributions

SDK Installation

The SDK can be installed with either npm, pnpm, bun or yarn package managers.

NPM

npm add @avalanche-sdk/webhooks

PNPM

pnpm add @avalanche-sdk/webhooks

Bun

bun add @avalanche-sdk/webhooks

Yarn

yarn add @avalanche-sdk/webhooks zod

# Note that Yarn does not install peer dependencies automatically. You will need
# to install zod as shown above.

[!NOTE] This package is published with CommonJS and ES Modules (ESM) support.

Model Context Protocol (MCP) Server

This SDK is also an installable MCP server where the various SDK methods are exposed as tools that can be invoked by AI applications.

Node.js v20 or greater is required to run the MCP server from npm.

Claude installation steps

Add the following server definition to your claude_desktop_config.json file:

{
  "mcpServers": {
    "Avalanche": {
      "command": "npx",
      "args": [
        "-y", "--package", "@avalanche-sdk/webhooks",
        "--",
        "mcp", "start",
        "--api-key", "...",
        "--chain-id", "...",
        "--network", "..."
      ]
    }
  }
}

Cursor installation steps

Create a .cursor/mcp.json file in your project root with the following content:

{
  "mcpServers": {
    "Avalanche": {
      "command": "npx",
      "args": [
        "-y", "--package", "@avalanche-sdk/webhooks",
        "--",
        "mcp", "start",
        "--api-key", "...",
        "--chain-id", "...",
        "--network", "..."
      ]
    }
  }
}

You can also run MCP servers as a standalone binary with no additional dependencies. You must pull these binaries from available Github releases:

curl -L -o mcp-server \
    https://github.com/{org}/{repo}/releases/download/{tag}/mcp-server-bun-darwin-arm64 && \
chmod +x mcp-server

If the repo is a private repo you must add your Github PAT to download a release -H "Authorization: Bearer {GITHUB_PAT}".

{
  "mcpServers": {
    "Todos": {
      "command": "./DOWNLOAD/PATH/mcp-server",
      "args": [
        "start"
      ]
    }
  }
}

For a full list of server arguments, run:

npx -y --package @avalanche-sdk/webhooks -- mcp start --help

Requirements

For supported JavaScript runtimes, please consult RUNTIMES.md.

SDK Example Usage

Example

import { Avalanche } from "@avalanche-sdk/webhooks";

const avalanche = new Avalanche();

async function run() {
  const result = await avalanche.webhooks.create({
    eventType: "address_activity",
    url: "https://sophisticated-exterior.org/",
    chainId: "<id>",
    metadata: {
      eventSignatures: [
        "0x61cbb2a3dee0b6064c2e681aadd61677fb4ef319f0b547508d495626f5a62f64",
      ],
      addresses: [
        "0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E",
      ],
    },
  });

  console.log(result);
}

run();

Authentication

Per-Client Security Schemes

This SDK supports the following security scheme globally:

Name	Type	Scheme
apiKey	apiKey	API key

To authenticate with the API the apiKey parameter must be set when initializing the SDK client instance. For example:

import { Avalanche } from "@avalanche-sdk/webhooks";

const avalanche = new Avalanche({
  apiKey: "<YOUR_API_KEY_HERE>",
});

async function run() {
  const result = await avalanche.webhooks.healthCheck();

  console.log(result);
}

run();

Available Resources and Operations

Available methods

webhooks

• healthCheck - Get the health of the service
• create - Create a webhook
• list - List webhooks
• get - Get a webhook by ID
• deactivate - Deactivate a webhook
• update - Update a webhook
• generateOrRotateSharedSecret - Generate or rotate a shared secret
• getSharedSecret - Get a shared secret

webhooks.addresses

• add - Add addresses to EVM activity webhook
• remove - Remove addresses from EVM activity webhook
• list - List adresses by EVM activity webhooks

Standalone functions

All the methods listed above are available as standalone functions. These functions are ideal for use in applications running in the browser, serverless runtimes or other environments where application bundle size is a primary concern. When using a bundler to build your application, all unused functionality will be either excluded from the final bundle or tree-shaken away.

To read more about standalone functions, check FUNCTIONS.md.

Available standalone functions

• webhooksAddressesAdd - Add addresses to EVM activity webhook
• webhooksAddressesList - List adresses by EVM activity webhooks
• webhooksAddressesRemove - Remove addresses from EVM activity webhook
• webhooksCreate - Create a webhook
• webhooksDeactivate - Deactivate a webhook
• webhooksGenerateOrRotateSharedSecret - Generate or rotate a shared secret
• webhooksGet - Get a webhook by ID
• webhooksGetSharedSecret - Get a shared secret
• webhooksHealthCheck - Get the health of the service
• webhooksList - List webhooks
• webhooksUpdate - Update a webhook

Pagination

Some of the endpoints in this SDK support pagination. To use pagination, you make your SDK calls as usual, but the returned response object will also be an async iterable that can be consumed using the for await...of syntax.

Here's an example of one such pagination call:

import { Avalanche } from "@avalanche-sdk/webhooks";

const avalanche = new Avalanche();

async function run() {
  const result = await avalanche.webhooks.list({
    status: "active",
  });

  for await (const page of result) {
    console.log(page);
  }
}

run();

Retries

Some of the endpoints in this SDK support retries. If you use the SDK without any configuration, it will fall back to the default retry strategy provided by the API. However, the default retry strategy can be overridden on a per-operation basis, or across the entire SDK.

To change the default retry strategy for a single API call, simply provide a retryConfig object to the call:

import { Avalanche } from "@avalanche-sdk/webhooks";

const avalanche = new Avalanche();

async function run() {
  const result = await avalanche.webhooks.healthCheck({
    retries: {
      strategy: "backoff",
      backoff: {
        initialInterval: 1,
        maxInterval: 50,
        exponent: 1.1,
        maxElapsedTime: 100,
      },
      retryConnectionErrors: false,
    },
  });

  console.log(result);
}

run();

If you'd like to override the default retry strategy for all operations that support retries, you can provide a retryConfig at SDK initialization:

import { Avalanche } from "@avalanche-sdk/webhooks";

const avalanche = new Avalanche({
  retryConfig: {
    strategy: "backoff",
    backoff: {
      initialInterval: 1,
      maxInterval: 50,
      exponent: 1.1,
      maxElapsedTime: 100,
    },
    retryConnectionErrors: false,
  },
});

async function run() {
  const result = await avalanche.webhooks.healthCheck();

  console.log(result);
}

run();

Error Handling

AvalancheError is the base class for all HTTP error responses. It has the following properties:

Property	Type	Description
error.message	string	Error message
error.statusCode	number	HTTP response status code eg 404
error.headers	Headers	HTTP response headers
error.body	string	HTTP body. Can be empty string if no body is returned.
error.rawResponse	Response	Raw HTTP response
error.data$		Optional. Some errors may contain structured data. See Error Classes.

Example

import { Avalanche } from "@avalanche-sdk/webhooks";
import * as errors from "@avalanche-sdk/webhooks/models/errors";

const avalanche = new Avalanche();

async function run() {
  try {
    const result = await avalanche.webhooks.healthCheck();

    console.log(result);
  } catch (error) {
    // The base class for HTTP error responses
    if (error instanceof errors.AvalancheError) {
      console.log(error.message);
      console.log(error.statusCode);
      console.log(error.body);
      console.log(error.headers);

      // Depending on the method different errors may be thrown
      if (error instanceof errors.BadRequestError) {
        console.log(error.data$.message); // errors.BadRequestMessage
        console.log(error.data$.statusCode); // number
        console.log(error.data$.error); // string
      }
    }
  }
}

run();

Error Classes

Primary errors:

• AvalancheError: The base class for HTTP error responses.
  • BadRequestError: Bad requests generally mean the client has passed invalid or malformed parameters. Error messages in the response could help in evaluating the error. Status code 400.
  • UnauthorizedError: When a client attempts to access resources that require authorization credentials but the client lacks proper authentication in the request, the server responds with 401. Status code 401.
  • ForbiddenError: When a client attempts to access resources with valid credentials but doesn't have the privilege to perform that action, the server responds with 403. Status code 403.
  • NotFoundError: The error is mostly returned when the client requests with either mistyped URL, or the passed resource is moved or deleted, or the resource doesn't exist. Status code 404.
  • TooManyRequestsError: This error is returned when the client has sent too many, and has hit the rate limit. Status code 429.
  • InternalServerError: The error is a generic server side error that is returned for any uncaught and unexpected issues on the server side. This should be very rare, and you may reach out to us if the problem persists for a longer duration. Status code 500.
  • BadGatewayError: This is an internal error indicating invalid response received by the client-facing proxy or gateway from the upstream server. Status code 502.
  • ServiceUnavailableError: The error is returned for certain routes on a particular Subnet. This indicates an internal problem with our Subnet node, and may not necessarily mean the Subnet is down or affected. Status code 503.

Less common errors (6)

Network errors:

• ConnectionError: HTTP client was unable to make a request to a server.
• RequestTimeoutError: HTTP request timed out due to an AbortSignal signal.
• RequestAbortedError: HTTP request was aborted by the client.
• InvalidRequestError: Any input used to create a request is invalid.
• UnexpectedClientError: Unrecognised or unexpected error.

Inherit from AvalancheError:

• ResponseValidationError: Type mismatch between the data returned from the server and the structure expected by the SDK. See error.rawValue for the raw value and error.pretty() for a nicely formatted multi-line string.

Server Selection

Override Server URL Per-Client

The default server can be overridden globally by passing a URL to the serverURL: string optional parameter when initializing the SDK client instance. For example:

import { Avalanche } from "@avalanche-sdk/webhooks";

const avalanche = new Avalanche({
  serverURL: "https://glacier-api.avax.network",
});

async function run() {
  const result = await avalanche.webhooks.healthCheck();

  console.log(result);
}

run();

Custom HTTP Client

The TypeScript SDK makes API calls using an HTTPClient that wraps the native Fetch API. This client is a thin wrapper around fetch and provides the ability to attach hooks around the request lifecycle that can be used to modify the request or handle errors and response.

The HTTPClient constructor takes an optional fetcher argument that can be used to integrate a third-party HTTP client or when writing tests to mock out the HTTP client and feed in fixtures.

The following example shows how to use the "beforeRequest" hook to to add a custom header and a timeout to requests and how to use the "requestError" hook to log errors:

import { Avalanche } from "@avalanche-sdk/webhooks";
import { HTTPClient } from "@avalanche-sdk/webhooks/lib/http";

const httpClient = new HTTPClient({
  // fetcher takes a function that has the same signature as native `fetch`.
  fetcher: (request) => {
    return fetch(request);
  }
});

httpClient.addHook("beforeRequest", (request) => {
  const nextRequest = new Request(request, {
    signal: request.signal || AbortSignal.timeout(5000)
  });

  nextRequest.headers.set("x-custom-header", "custom value");

  return nextRequest;
});

httpClient.addHook("requestError", (error, request) => {
  console.group("Request Error");
  console.log("Reason:", `${error}`);
  console.log("Endpoint:", `${request.method} ${request.url}`);
  console.groupEnd();
});

const sdk = new Avalanche({ httpClient });

Debugging

You can setup your SDK to emit debug logs for SDK requests and responses.

You can pass a logger that matches console's interface as an SDK option.

[!WARNING] Beware that debug logging will reveal secrets, like API tokens in headers, in log messages printed to a console or files. It's recommended to use this feature only during local development and not in production.

import { Avalanche } from "@avalanche-sdk/webhooks";

const sdk = new Avalanche({ debugLogger: console });

Development

Maturity

This SDK is in beta, and there may be breaking changes between versions without a major version update. Therefore, we recommend pinning usage to a specific package version. This way, you can install the same version each time without breaking changes unless you are intentionally looking for the latest version.

Contributions

While we value open-source contributions to this SDK, this library is generated programmatically. Any manual changes added to internal files will be overwritten on the next generation. We look forward to hearing your feedback. Feel free to open a PR or an issue with a proof of concept and we'll do our best to include it in a future release.