krpc-go is a Go client for kRPC, a Kerbal Space Program mod for controlling the game with an external program.

go get github.com/atburke/krpc-go

This sample program will launch a vessel sitting on the launchpad. Error handling is omitted for brevity.

package main

import (
    "context"

    krpcgo "github.com/atburke/krpc-go"
    "github.com/atburke/krpc-go/krpc"
    "github.com/atburke/krpc-go/spacecenter"
)

func main() {
    // Connect to the kRPC server with all default parameters.
    client := krpcgo.DefaultKRPCClient()
    client.Connect(context.Background())
    defer client.Close()

    sc := spacecenter.New(client)
    vessel, _ := sc.ActiveVessel()
    control, _ := vessel.Control()

    control.SetSAS(true)
    control.SetRCS(false)
    control.SetThrottle(1.0)
    control.ActivateNextStage()
}

This section describes type mappings from the kRPC protocol.

• Primitives are mapped to Go primitives.
• Arrays are mapped to slices. Dictionaries and sets are mapped to maps.
• Tuples are mapped to a special tuple type in the types package. For example, a tuple of strings would map to types.Tuple3[string, string, string].
  • types also contains some convenience types that can be converted to/from the appropriate tuple, such as types.Vector2D, types.Vector3D, and types.Color.
• Classes and enums are mapped to local structs and constants defined in the appropriate service. For example, a Vessel will be mapped to a *spacecenter.Vessel, and a GameScene will be mapped to a krpc.GameScene.
• Existing protobuf types can be found in the types package. For example, a Status will be mapped to a *types.Status.

krpc-go uses Go's built-in channels to handle streams.

Here's an example of using streams to autostage a vessel until a specific stage is reached.

func AutoStageUntil(vessel *spacecenter.Vessel, stopStage int32) {
    go func() {
        control, _ := vessel.Control()
        stage, _ := control.CurrentStage()

        for stage > stopStage {
            resources, _ := vessel.ResourcesInDecoupleStage(stage-1, false)
            amountStream, _ := resources.AmountStream("LiquidFuel")

            // Wait until this stage runs out of liquid fuel.
            for amount := <-amountStream.C; amount > 0.1 {}

            amountStream.Close()
            control.ActivateNextStage()
            stage--
        }
    }()
}

See tests in integration/ for more usage examples.

TODO

TODO krpc-go docs link kRPC documentation