API documentation for OnlineSim

Interactive OpenAPI docs with auth guides, schemas, code samples, and Try It Out — in multiple languages.

Browse APIsOpen first API
GET/api/getBalance.php
curl \  'https://onlinesim.io/api/getBalance.php' \  -G -d 'apikey=YOUR_KEY'
200 OK

How does this work?

Three steps from catalog to a working request.

1

Choose an API

Pick a specification from the catalog and open its overview.

2

Set up auth

Follow the authentication guide for keys, OAuth, or headers.

3

Try It Out

Send live requests and copy ready-made code samples.

Available APIs

Select a specification to explore endpoints and examples.

APIv1.1

Onlinesim API

General description This API will allow you to access all services provided by Onlinesim: SMS receiving from a single specific service on a virtual nu

  • Interactive Try It Out
  • EN, RU, DE
  • Code samples & schemas
Open docs
APIv1.0

Reseller API

General description The API is intended for current and potential Onlinesim partners. It allows you to monetize your numbers by providing them to our

  • Interactive Try It Out
  • EN, RU, DE
  • Code samples & schemas
Open docs
APIv1.0

Alternative API

General description Alternative API for integration with Onlinesim. This API will allow you to access two main services of Onlinesim: rent numbers to

  • Interactive Try It Out
  • EN, RU, DE
  • Code samples & schemas
Open docs

Also available

Beyond REST APIs — run Onlinesim tools from your AI client.

MCP

Onlinesim MCP

Local CLI + Streamable HTTP MCP server for SMS numbers — install once, connect Cursor, Claude, VS Code, or Codex.

  • One-line install (macOS, Linux, Windows)
  • 14 tools for Quick SMS and rentals
  • Works with Cursor, Claude Code, VS Code, Codex
Open MCP docs

FAQ

Quick answers about using this documentation.

Open the catalog below. Each card shows the title, version, and locales. Start with the API that matches your integration.