Microsip Api Documentation May 2026

This is the more powerful interface. Any Windows application can send a WM_COPYDATA message to MicroSIP’s main window (class "MicroSIP"). The dwData field identifies the command, and lpData contains a UTF-8 string with parameters.

In the world of Voice over IP (VoIP), efficiency and footprint matter. While heavyweight softphones like Zoiper or X-Lite offer graphical bells and whistles, they often consume system resources and lack true automation capabilities. Enter MicroSIP—a free, open-source, lightweight SIP softphone for Windows that weighs under 300KB.

However, MicroSIP’s true superpower isn’t just its minimalism; it’s its rich, undocumented-but-discoverable API. Unlike most softphones that hide behind GUI-only operations, MicroSIP exposes dozens of command-line parameters and DDE (Dynamic Data Exchange) commands. This allows you to integrate click-to-dial functionality, automate call logging, trigger system scripts, and embed telephony directly into CRM systems like Salesforce, VTiger, or even custom ERP software.

This article serves as the definitive reference for MicroSIP API documentation. You will learn the syntax, real-world examples, and integration patterns. microsip api documentation

Note: MicroSIP does not provide a RESTful HTTP API. Its "API" is a hybrid of command-line arguments (for launching) and DDE commands (for runtime control).

MicroSIP can also send notifications to your application. When an incoming call arrives, a call is connected, or status changes, MicroSIP can execute an external program or send a window message.

The DDE interface is what transforms MicroSIP into an integrated telephony component. You can send commands while the softphone runs in the background (even in system tray). This is the more powerful interface

In the world of Voice over IP (VoIP), efficiency and customization are paramount. While many users rely on graphical interfaces for softphones, power users, IT administrators, and developers often need something more: programmatic control.

MicroSIP is a lightweight, open-source Windows SIP softphone renowned for its minimal resource usage (under 5MB of RAM) and exceptional audio quality. However, its true hidden power lies not in its GUI, but in its Command Line Interface (CLI) and Windows Messaging API.

While MicroSIP does not expose a traditional REST API or JSON web service, its rich API via command-line arguments and window messages allows any application—be it a CRM, a Python script, a batch file, or a web application—to control the phone seamlessly. Note : MicroSIP does not provide a RESTful HTTP API

This article serves as the definitive resource for MicroSIP API documentation, covering every parameter, message type, and practical integration example.

Since there is no REST API, "integrating" with MicroSIP typically involves:

The SendMessage call returns an LRESULT:

Limitation: No asynchronous callback or event notification. The calling process must poll STATUS to detect incoming calls or call termination.