Open source · Cross-platform

A lightweight
API testing client

Test and debug HTTP requests with a fast, focused desktop app. Built-in MCP server for AI-powered workflows. No bloat, no account required.

Download Read the Docs

GET

https://api.example.com/users

Params Headers Body Auth

page 1

limit 25

Body Headers

200 OK 124ms

{
  "users": [
    { "id": 1, "name": "Alice" },
    { "id": 2, "name": "Bob" }
  ]
}

Everything you need, nothing you don't

Focused tools for API testing without the bloat.

9 HTTP Methods

Full support for GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS, CONNECT, and TRACE.

Authentication

Bearer Token, Basic Auth, and API Key (header or query param) built right in.

Environments

Define variables per environment and use {{variable}} syntax anywhere in your requests.

cURL Import

Paste any cURL command directly into the URL bar. Method, headers, body, and auth are auto-detected.

Collections

Organize requests into collections. Pin favorites, reorder with drag-and-drop, and run in bulk.

MCP Integration

Built-in MCP server lets AI agents like Claude, Cursor, and Warp manage your API workflows.

Powerful Request Builder

Craft requests with 6 body types (JSON, Form Data, URL Encoded, XML, Raw, None), query parameters, custom headers, and multiple auth methods. Color-coded HTTP methods make it easy to scan.

JSON, XML, Form Data, URL Encoded, Raw Text
Query params and headers with toggle controls
Per-request timeout and retry settings

GETPOSTPUTPATCHDELETE

JSON

Form Data

URL Encoded

XML

Raw Text

Rich Response Viewer

Inspect responses with syntax-highlighted JSON and XML, an interactive tree view with expand/collapse, in-body search with Ctrl+F, and a clear status bar showing code, time, and size.

JSON tree view with expand all / collapse all
Ctrl+F search with match navigation
Status code, duration, and response size at a glance

200 OK | 124ms | 2.4 KB

{

"status": "success",

"count": 42,

"data": [

{ ... }

]

}

AI-Native with MCP

Reqline exposes an MCP server over Streamable HTTP, letting AI agents manage collections, execute requests, and work with environments. Connect Claude Desktop, Cursor, or Warp in seconds.

20+ MCP tools for full API workflow automation
Streamable HTTP transport at localhost:3218
Headless stdio mode for CI pipelines

# MCP config (Claude Desktop / Cursor / Warp)

{
  "mcpServers": {
    "reqline": {
      "url": "http://127.0.0.1:3218/mcp"
    }
  }
}

Download Reqline

Available for macOS, Windows, and Linux. Free and open source.

A lightweight API testing client