FSUIPC (Flight Simulator Universal Inter-Process Communication) is a foundational utility for flight simulators like Microsoft Flight Simulator (MSFS) and Lockheed-Martin's Prepar3D . While it is traditionally accessed via C++ or Lua, Python has become a powerful way to interact with its "inner workings" through third-party wrappers . The Role of FSUIPC
At its core, FSUIPC acts as a middleman between the simulator and external applications . It manages a 65,535-byte memory block populated with live simulator data, such as altitude, pitch, and heading . Each specific piece of data is stored at a unique address known as an "offset" . By reading from or writing to these offsets, developers can build custom dashboards, external hardware interfaces, or automation scripts . Interfacing with Python
Because FSUIPC is a Windows-based DLL/EXE, Python developers rely on client wrappers to communicate with its memory map.
fsuipc (PyPI/GitHub): A popular Python client wrapper that provides a simple class-based interface to read and write offsets. It is built on top of pyuipc and is specifically for Windows platforms .
pyfsuipc: An alternative Cython-based module compatible with Python 3, though it is often noted as being in more experimental phases . Performance and Data Handling
Using Python for simulator telemetry can encounter bottlenecks if not optimized.
High-Frequency Updates: In some implementations, generating high-frequency telemetry (e.g., 60 updates per second) through FSUIPC can cause significant dashboard lag .
System Impact: While FSUIPC itself uses minimal GPU resources, it can impact FPS if the CPU is heavily loaded. It includes features to set an affinity mask, allowing it to run on separate CPU cores to minimize simulator stutters . Common Use Cases tjensen/fsuipc: Python client wrapper for FSUIPC - GitHub
Fsuipc is built on top of (and includes) pyuipc fsuipc only supports Python on Windows platforms. voneiden/pyfsuipc: Python 3 compatible Cython ... - GitHub
FSUIPC Python is the "secret handshake" between the Python programming language and flight simulators like Microsoft Flight Simulator (MSFS) and Lockheed Martin’s Prepar3D. It allows you to read real-time data—like your altitude, airspeed, or engine temperature—and even send commands back to the plane, turning a flight sim into a programmable playground. 🔌 How the Magic Works At its core,
acts as a massive shared memory bank. It tracks thousands of "offsets" (specific hex addresses) that store every imaginable variable about your flight. Python interacts with this via a client wrapper, most commonly the fsuipc library on GitHub
, which translates those complex memory addresses into readable Python code. 🛠️ What You Can Build fsuipc python
With Python and FSUIPC, you aren't just flying; you're engineering. Here are a few ways pilots use this combo: Custom Glass Cockpits
: Build your own instrument panels on a secondary monitor or a tablet using Python GUI libraries like Tkinter or PyQt. Smart Automation
: Script "virtual co-pilots" that automatically handle landing lights at 10,000 feet or manage fuel pumps during long-haul flights. Data Logging & Analysis
: Export every second of your flight to a CSV file to analyze your landing flare or visualize your route on a map later. Hardware Integration
: Connect physical LED displays or custom DIY switches (via Arduino or Raspberry Pi) that react to what is happening inside the simulator. 🚀 Getting Started in 3 Steps Install FSUIPC
: You need the FSUIPC plugin installed in your flight simulator (MSFS, P3D, or FSX). Install the Library : In your terminal, run: pip install fsuipc Read Your Altitude
: A tiny script is all it takes to see your height in real-time: fsuipc.FSUIPC() # 0x3324 is the offset for altitude in feet = ipc.read_fixed_point( ) print( Current Altitude: altitude Use code with caution. Copied to clipboard ⚠️ The Catch The main hurdle is that FSUIPC is Windows-only
, as the simulators it supports are built for Windows architecture. Additionally, while reading data is straightforward, writing commands (like toggling a switch) requires a bit of research into the specific FSUIPC Offset Documentation to ensure you're talking to the right memory address. sample script to automate a specific cockpit task, or should we look into connecting hardware like an Arduino?
To produce a functional feature using Python and FSUIPC , you can use the
library, which acts as a client wrapper for the FSUIPC tool to read and write simulator data. Feature: Real-Time Telemetry Monitor
This feature allows you to extract live data—such as latitude, longitude, and altitude—directly from your flight simulator (MSFS, FSX, or P3D) for use in external Python scripts. Microsoft Flight Simulator Forums Install the necessary library via pip: pip install fsuipc Use code with caution. Copied to clipboard Note: FSUIPC Python support is exclusive to platforms. 2. Implementation Script : Read variables like engine RPM, fuel levels,
The following code demonstrates how to open a connection and read specific memory (data points) from the simulator: # offsets for Latitude, Longitude, and Altitude LAT_OFFSET LON_OFFSET ALT_OFFSET # Prepare the data structure for reading # "l" indicates a long integer (64-bit) for high precision = fsuipc.prepare_data([ (LAT_OFFSET, ), (LON_OFFSET, ), (ALT_OFFSET, )
print( Connected to Simulator. Press Ctrl+C to stop. = prepared.read() # Convert internal FSUIPC units to standard units if needed # For simplicity, printing raw values from the offsets )
time.sleep( # Update every second KeyboardInterrupt: Use code with caution. Copied to clipboard Key Capabilities Data Extraction</p>
: Read variables like engine RPM, fuel levels, or landing gear status via memory offsets. Simulator Control
: Write to offsets to "spoof" values or trigger events, such as toggling landing lights ( 0 x 028 cap C Compatibility
: This interface works across legacy and modern sims, including (via FSUIPC7), Microsoft Flight Simulator Forums
For a complete list of what data you can access, refer to the FSUIPC Offsets Documentation provided by Project Magenta. Project Magenta tjensen/fsuipc: Python client wrapper for FSUIPC - GitHub 10 Nov 2022 —
Interfacing with the Skies: The Role of Python in the FSUIPC Ecosystem
The world of flight simulation has evolved from simple pixelated horizons to hyper-realistic digital twins of our planet. For enthusiasts and developers alike, the ability to extract data from or send commands to simulators like Microsoft Flight Simulator (MSFS) or Prepar3D is crucial. At the heart of this bridge lies FSUIPC (Flight Simulator Universal Inter-Process Communication), and for modern developers, Python has become the language of choice for building custom cockpits, automated flight recorders, and virtual airline clients. The Bridge: Understanding FSUIPC
FSUIPC acts as a standardized interface. Flight simulators are complex engines that don't always expose their internal variables (like airspeed, altitude, or fuel flow) in a format that external software can easily read. FSUIPC maps these internal values to "offsets"—specific memory addresses that can be consistently accessed regardless of the simulator version. This creates a stable environment for third-party developers. Why Python?
While FSUIPC was traditionally accessed via C++ or C#, Python's rise in the flight sim community is driven by several factors:
Rapid Prototyping: Python’s simple syntax allows developers to write a script that pulls live altitude data in just a few lines of code.
Library Support: Libraries such as pyFSUIPC or fsuipc-python (built on top of the FSUIPC SDK) handle the complex memory management and pointer logic under the hood, allowing the user to focus on their application logic. Altitude : Feet for offset 0x0570, meters for
Data Science Integration: Because Python is the leader in data analysis, it is the perfect tool for flight data monitoring (FDM). Pilots can export their flight paths to Pandas dataframes to analyze landing rates or fuel efficiency. Practical Applications
The synergy between Python and FSUIPC enables a wide array of projects:
Custom Hardware Interfaces: Using a Raspberry Pi or Arduino, a user can write a Python script to sync physical LED displays with the "Autopilot Altitude" offset in the sim.
Smart Co-Pilots: Developers use Python to create "virtual first officers" that monitor checklists. If FSUIPC reports the landing gear is still up below 1,000 feet, the script can trigger a voice warning.
Virtual Airline (VA) Tracking: Most VAs use background clients to ensure pilots fly realistically. Python scripts can monitor for "overspeed" or "excessive bank angle" events through FSUIPC and log them to a web server. The Technical Hurdle
Using Python with FSUIPC typically requires the FSUIPC7 (for MSFS) or earlier versions (for P3D/FSX) to be running as a background process. The Python script connects to this process via an IPC (Inter-Process Communication) link. Developers must be mindful of "polling rates"—requesting data too frequently can cause stutters in the simulator, while requesting it too slowly makes instruments feel laggy. Conclusion
FSUIPC remains the "Swiss Army Knife" of flight simulation connectivity, and Python is the modern handle that makes it accessible. Whether for a hobbyist building a home cockpit or a developer creating the next big flight-tracking app, the combination of FSUIPC and Python democratizes flight sim development, turning complex aeronautical data into a playground for creativity.
Refer to the FSUIPC Offset Status.pdf – it’s your bible.
import fsuipc
import struct
fs = fsuipc.connect()
Events vs Offsets
- Events: trigger simulator actions (e.g., TOGGLE_GEAR). Safer for simulator-managed state.
- Offsets: direct memory read/write for variables; powerful but can conflict with simulator logic if used incorrectly.
Connect to the simulator (auto-detects running sim)
fs = fsuipc.connect()
fsuipc.IPC.read(name, type)
Read data from FSUIPC.
name: Name of the data to readtype: Type of the data to read (e.g. fsuipc.FLOAT, fsuipc.INT)- Returns: The read value