Puter API Client: a free, open-source Postman alternative

Build, send and test HTTP and WebSocket requests, with collections, environments and scripts.

Developer tools
Free · MIT
Runs in the browser
alpha

The official repository hasn’t published a hosted link for this app yet — you can run it from source with the steps below.

From the official README: this app is in early alpha. Features may change and data could be lost — don’t rely on it for real work yet, and keep copies of anything important.

What is API Client?

API Client is a workbench for the APIs you build and use. Compose requests with params, headers, auth and any body type, read responses pretty-printed with timing details, organise collections and switch environments, write pre-request and test scripts, and import Postman collections, OpenAPI, HAR, Insomnia or cURL.

Key features

Request builder: params, headers, auth (OAuth 2.0, AWS Sig…) and bodies
Response viewer with JSON filter, timing and size
Collections, environments, variables and history
Test scripts and a collection runner with data files
WebSocket, imports (OpenAPI, HAR, cURL) and code in 17 languages

How to use it

No hosted version yet — run it from source with the commands below.
Sign in with a free Puter account; your data is saved in your own Puter cloud storage.
Want to self-host or hack on it? Run it locally (Node.js 22.12 or newer):

git clone https://github.com/HeyPuter/everything.git
cd everything/src/api-client
npm install
npm run dev

FAQ

Is API Client free?

Yes. API Client is part of the Everything Project and its source code is published on GitHub under the MIT license. There is no subscription or trial.

Do I need to install API Client?

The official hosted version hasn’t been published yet. You can run it locally with the “Run it from source” steps below (Node.js 22.12 or newer).

Do I need an account to use API Client?

A free Puter account. Your data is stored in your own Puter cloud storage.

Can API Client replace Postman?

Not fully yet. API Client is in alpha: features will change, and its README asks you not to rely on it for real work or important data. Try it out, and keep backups of anything important.

Summarised from API Client’s README in the official repository. CraftSuite is an independent, unofficial guide and is not affiliated with Puter; Postman, Insomnia and Hoppscotch are trademarks of their respective owners.