Details of the SDK release:
Welcome to the Construct 3 plugin SDK forum! Here we'll be providing information and support to third-party plugin developers interested in working with Construct 3.
Note you must use Construct 3 r15 or above for the SDK to work properly.
Current state of the SDK
The full set of editor SDKs we plan to support are very broad and involve a very large API surface. To approach this large task, we are going to gradually roll out the SDK in phases.
At first, the plugin SDK only supports single-global plugin types. (That means plugins that do not draw to the Layout View.) We hope to expand on this to drawing plugins, behaviors, effects and editor addons in future.
We have provisional SDK documentation available here:
The SDK documentation will eventually be hosted on construct.net, but the new documentation system isn't ready yet. Currently the documentation is hosted on scirra.com but likely will be moved in future.
This should help get you going with developing Construct 3 addons. Again this only covers single-global plugins; we'll update the documentation accordingly as we roll out new features and make new APIs available.