Documentation: Microsip Api

MicroSIP.exe volume 80

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.

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

MicroSIP responds to Windows messages, allowing external apps to control it:

// Example C/C++ code to send commands
HWND hWnd = FindWindow(NULL, L"MicroSIP");
if (hWnd) 
    // Make a call
    COPYDATASTRUCT cds;
    cds.dwData = 1;
    std::wstring number = L"sip:1234567890@domain.com";
    cds.cbData = (number.length() + 1) * sizeof(wchar_t);
    cds.lpData = (PVOID)number.c_str();
    SendMessage(hWnd, WM_COPYDATA, (WPARAM)hWnd, (LPARAM)&cds);

The most common API call: initiate a voice call.

MicroSIP.exe callto:+1234567890

Or:

MicroSIP.exe sip:user@domain.com

Options:

You can automate the setup of SIP accounts by writing to this section.

[Account]
Account=name@example.com      ; The SIP username/domain
Domain=example.com            ; SIP Domain (optional)
Proxy=sip:proxy.example.com   ; Outbound proxy (optional)
AuthID=1001                   ; Authentication ID (if different from username)
Password=secret123            ; Plain text password
DisplayName=John Doe          ; Caller ID Name

A Python script can act as a bridge:

import win32gui
import win32con
import struct
def dial_microsip(number):
hwnd = win32gui.FindWindow(None, "MicroSIP")
if hwnd:
data = number.encode('utf-8')
cds = struct.pack("IIP", 1, len(data)+1, id(data))  # dwData=1 (DIAL)
win32gui.SendMessage(hwnd, win32con.WM_COPYDATA, 0, cds)

MicroSIP does not need a bloated REST API. Its command-line and Windows messaging interface provide a remarkably robust, low-latency, and memory-efficient way to integrate VoIP into any Windows application. From one-line batch scripts to complex CRM integrations, understanding the MicroSIP API documentation unlocks professional-grade telephony automation on commodity hardware.

Whether you are building a click-to-dial system, an automated IVR tester, or a home assistant voice notification service, the tools are already there—lightweight, free, and documented right here.

Next Steps:

Last updated: 2025. This guide is not official MicroSIP documentation but a community-driven reference based on source code analysis and production experience. Always test API commands in a staging environment first. MicroSIP

MicroSIP itself is a lightweight open-source SIP softphone. Its "API" is primarily exposed via command-line arguments and Windows messages (WM_COPYDATA) , allowing external apps to control it.