Primary aircraft systems
Controls, gear, engines, fuel, electrical, hydraulics, pneumatics, APU, lighting, ice protection, cabin, oxygen, pressurization, warnings, weight and balance, dynamics, and more.
UNIFIED FLIGHT SIMULATOR SDK
One aircraft.
One aircraft.
One API.
A mature, discoverable C# object model for simulator data, aircraft systems, weather, flight planning, automation, AI, and MCP—without making application developers learn SimConnect, DataRefs, native commands, or provider quirks.
MSFS 2020MSFS 2024X-Plane 12Extensible providers
using USI.Core;
using var usi = new USI();
var running = usi.DetectAll();
var connection = await usi.TryConnectAsync(
running[0].ProviderId);
var airspeed = usi.Aircraft.Avionics
.GetComponent<Airspeed>("Airspeed");
var ias = await airspeed!
.TryGetIndicatedAirspeedAsync();
Console.WriteLine(ias.Value);
// Same code. Every supported simulator.THE FUNDAMENTAL TRUTH
Every simulator models an aircraft.
Airspeed is airspeed. Altitude is altitude. A developer should not have to learn a different SDK to ask the same aviation question.
01Provider raw valueSimVar, DataRef, event, command, client data, or plugin message.
→
02SDK normalizationMeaning, units, scale, polarity, validity, and lifecycle are reconciled.
→
03User preferencesAviation, metric, or US customary measurements are projected consistently.
→
04Readable C#Typed results and an IntelliSense-friendly aircraft model reach the application.
THE COMPLETE TOP STACK
More than a variable wrapper.
USI unifies the aircraft, the surrounding simulator, and the services developers build around a flight.
Guidance and navigation
Autopilot, flight directors, autothrottle, COM/NAV/ADF, GPS, transponders, EFIS, sensors, displays, weather radar, and discoverable named components.
Lifecycle and world services
Connection, aircraft lifecycle, time, environment, facilities, traffic, ATC, camera, replay, saved flights, missions, scenarios, presentation, policies, and extensions.
Aviation weather
Live simulator atmosphere plus METAR, TAF, PIREPs, SIGMETs, AIRMETs, advisories, winds aloft, stations, runways, navaids, and reference data.
SimBrief flight planning
Normalized operational flight plans, navlogs, fuel, aircraft, route, briefing links, weather enrichment, and provider-neutral simulator import.
Automation, AI, and MCP
A governed operation gateway, simulator-grounded assistants, speech integrations, and a developer-launched MCP server with explicit read/write policy.
CURRENT SDK DISPOSITION
Source-code complete across all three providers.
The current public surface has an intentional semantic disposition for Microsoft Flight Simulator 2020, Microsoft Flight Simulator 2024, and X-Plane 12: native support, exact derivation, or an explicit typed unsupported outcome where no truthful provider equivalent exists.
Understand provider coverage →3Built-in providers
100%Manifest disposition
4,222Harness checks passing
0Provider branches required in app code
PROVIDER ARCHITECTURE
Differences end below the SDK boundary.
Native adapters are essential, but they are implementation detail—not application architecture.
| Provider | Bottom-stack integration | Developer experience |
|---|---|---|
| Microsoft Flight Simulator 2020 | Native SimConnect adapter and provider capability manifest. | Common USI.Core aircraft and simulator objects. |
| Microsoft Flight Simulator 2024 | Shared Microsoft foundation with explicit 2024 deltas and its own provider identity. | The same objects, methods, events, results, and measurement preferences. |
| X-Plane 12 | Native plugin adapter for DataRefs, commands, messages, and lifecycle. | No DataRef names, conversions, or X-Plane branches in application code. |
| Future simulators | Implement the provider contract and truthful capability dispositions. | Existing applications retain the same top-stack API. |
BUILD FOR THE AIRCRAFT, NOT THE SIMULATOR
Start with one coherent aviation SDK.
Explore the module-oriented reference, search every public type, and follow complete signatures generated directly from the current assemblies.