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Node polyfills

Any version prior to Node 18 will need to provide polyfills.

The Tableland SDK makes use of the fetch API as well as Headers. If you're using a version of Node that came before the current LTS 18.x version, you'll need to either update to Node 18 or implement a polyfill.


To use a polyfill, you'll first need to install node-fetch.

npm install node-fetch

Starting with node-fetch v3, it is an ESM-only module; you are not able to import it with require(). If you cannot switch to ESM and need CommonJS (CJS) support, you could use v2 ([email protected])—or choose to use an async import().

Add the polyfill

In your source file, import fetch, Headers, Request, and Response from node-fetch. Then, you'll patch the global object in Node (globalThis), thus, enabling Tableland SDK compatability.

import fetch, { Headers, Request, Response } from "node-fetch";

if (!globalThis.fetch) {
globalThis.fetch = fetch;
globalThis.Headers = Headers;
globalThis.Request = Request;
globalThis.Response = Response;

Note that if you're using TypeScript, you can just declare globalThis as any in the ESM example declarations above (i.e., add a type to all of the references to globalThis).