How do I start using the Microsoft Flight Simulator SDK?
The Microsoft Flight Simulator SDK is the official toolkit of in-simulator editors, build tools, documentation and samples used to create aircraft, airports, scenery, instruments and activities for MSFS. To start, use the PC version, enable Developer Mode, install the matching SDK, create a source project, then build and test its package.
What does the Microsoft Flight Simulator SDK include?
The SDK includes the tools and technical definitions needed to turn source material into packages Microsoft Flight Simulator can load. It is not one aircraft-design application or a one-click converter for older add-ons.
- Developer Mode editors: These include the Project Editor, Scenery Editor and specialist tools appropriate to the selected simulator and content type.
- Package-building tools: The builder processes source files, validates references and produces the distributable package structure.
- Simulation interfaces: Developers can create instruments using supported web or WASM technologies, or connect external utilities through SimConnect.
- Documentation and samples: These explain package definitions, aircraft configuration, materials, animations, scenery objects and other supported systems.
The SDK does not require a separate purchase, but it is accessed through a licensed Windows PC installation of Microsoft Flight Simulator. Players installing finished add-ons do not need it; our collection of finished MSFS aircraft, scenery and utility packages shows the sort of output developers distribute.
How do you install and start the MSFS SDK?
Install the SDK from Developer Mode in the PC simulator, then create a separate source workspace rather than developing inside the Community folder.
- Choose the target simulator. Use the MSFS 2020 SDK for a package intended for Microsoft Flight Simulator 2020 and the MSFS 2024 SDK for a native 2024 project. Keep the simulator fully updated before installing its matching SDK.
- Enable Developer Mode. Open the simulator settings, locate the developer options and switch
Developer Modeon. A toolbar should appear across the top of the simulator; our reference to Developer Mode keyboard controls and shortcuts covers the everyday controls used while testing. - Run the SDK installer. Open the Developer Mode toolbar and select
Help > SDK Installer. Run the downloaded installer and include any documentation or sample components offered for that SDK release. - Create a clean source folder. Use a short local path, such as a folder named
MSFS-Dev/MyProject. Cloud-synchronised locations, deeply nested paths and unusual characters can cause file locks or obscure build errors. - Create the project and package. Open Project Editor, start a new project, add a package and select the asset group appropriate to scenery, a SimObject, an instrument or another supported content type. Give the package a simple, unique identifier.
- Add one test asset. For a first scenery project, place or alter a single object and save the scenery. For an aircraft project, begin from an SDK sample or documented template rather than an extracted stock or encrypted aircraft.
- Build the package. Use the package build command in Project Editor and read the console from the first reported error. Let the Package Builder create files such as
manifest.jsonandlayout.json; manually editing generated output usually causes the package index to become stale. - Test the built output. Developer Mode can mount a project during development, but the final test should use only the built package in the Community folder, with Developer Mode switched off and the simulator restarted. Our explanation of how MSFS 2024 recognises an installed scenery package shows the expected package root and the common one-folder-too-deep mistake.
Keep the editable source project and the built package separate. The package in the Community folder is a test or release build, not a safe substitute for the original models, textures, configuration files and project definitions.
Which SDK project should a beginner choose?
A small airport or scenery edit is usually the clearest first SDK project because it teaches placement, saving, building and package mounting without requiring aircraft systems code.
| Project goal | Main tools or skills | Good first project? |
|---|---|---|
| Airport or scenery edit | Scenery Editor, object placement and exclusions | Yes; start with one visible change |
| Aircraft livery | Texture editing and aircraft variation configuration | Yes, if comfortable editing textures |
| Instrument or gauge | Supported HTML/JavaScript or WASM development | Only with programming experience |
| External utility | SimConnect client and an external application | Suitable for application developers |
| Complete aircraft | Models, animations, flight configuration, systems and sounds | No; it combines several separate disciplines |
Choose scenery when the aim is to learn the SDK build loop. Choose a livery when the artwork is the main task, SimConnect for an external application, and a full aircraft only after smaller SimObject and instrument projects build reliably.
Can one SDK project work in MSFS 2020 and MSFS 2024?
No SDK project should be assumed to work unchanged in both MSFS 2020 and MSFS 2024. A 2020 package may load in 2024 through compatibility support, but the SDKs are not interchangeable and revised aircraft, material, avionics or activity systems can require migration.
Build the 2020 edition with the 2020 toolchain and the 2024 edition with the 2024 toolchain. If supporting both, preserve the working 2020 source, create a separate 2024 branch and test each output in a clean installation of its target simulator. A package built with 2024-only features will not become 2020-compatible by changing its manifest.
Why does my SDK package not appear in MSFS?
Most missing SDK packages are caused by an unbuilt project, incorrect folder nesting, a duplicate mounted package or an asset-group error rather than the simulator failing to scan the Community folder.
| Symptom | Likely cause and fix |
|---|---|
| SDK Installer is missing | Confirm that this is the Windows PC simulator, Developer Mode is enabled and the simulator has been restarted after updating. |
| Build completes but nothing appears | Copy the built package, not the source project. Check that manifest.json and layout.json are directly inside the package folder. |
| Saved changes are ignored | An older Community copy may share the same package name as the mounted development build. Remove the old copy and restart before retesting. |
| Package Builder stops immediately | Read the first error, not the later cascade. Check the project definition, package identifier, asset-group type and referenced source paths. |
| Models appear without textures | Check exported material assignments, relative texture paths and filename case. Rebuild after correcting the source rather than editing the compiled package. |
| An airport appears twice | The project may be adding a second airport definition instead of overriding the intended one. Verify its identifier and use the appropriate exclusions or airport override tools. |
Can SDK add-ons be distributed on PC and consoles?
Built Community packages can be distributed for manual installation on PC, but console users cannot run the SDK or sideload Community-folder add-ons. Xbox distribution, and PlayStation distribution for MSFS 2024, requires an approved in-simulator publishing route and may be subject to platform-specific restrictions.
The SDK builds content; it does not automatically publish it. Our comparison of Marketplace and manual add-on distribution explains the practical differences for developers and users.
- Test the release with Developer Mode off and no unrelated Community packages loaded.
- Confirm that extracting the archive creates one package folder, not an extra wrapper folder.
- Test every simulator version claimed in the description instead of assuming compatibility.
- Do not redistribute stock simulator files, encrypted Marketplace content or third-party assets without permission.