| name | krpc-programming |
| description | Comprehensive knowledge base for kRPC (Kerbal Remote Procedure Call), an external scripting framework for Kerbal Space Program. Covers architecture, client libraries (Python/C#/Lua/Java), connection setup, SpaceCenter API, AutoPilot, Vessel control, reference frames, streaming data, event system, extending with custom services, and community resources. Compiled from official kRPC documentation (v0.5.4), GitHub, and community sources.
|
| author | Acea |
| sources | ["https://krpc.github.io/krpc/","https://krpc.github.io/krpc/getting-started.html","https://krpc.github.io/krpc/tutorials/autopilot.html","https://krpc.github.io/krpc/extending.html","https://krpc.github.io/krpc/third-party.html","https://github.com/krpc/krpc","https://genhis.github.io/KRPC.MechJeb/"] |
| category | gaming |
| version | 1 |
| last_updated | "2026-06-17T00:00:00.000Z" |
| applies_when | directory_exists:GameData/kRPC |
kRPC Programming — Remote Procedure Call for KSP
⚠ CONDITIONAL SKILL: This knowledge base applies only when kRPC is installed in the current KSP instance. To verify: check that the directory GameData/kRPC exists within the KSP installation folder. If this directory is not present, the information below may not be relevant to the user's current setup.
Detection method:
ls -d <KSP_ROOT>/GameData/kRPC 2>/dev/null && echo "kRPC installed" || echo "kRPC NOT installed"
Test-Path "<KSP_ROOT>\GameData\kRPC" -PathType Container
This .skill file is a structured world knowledge base for LLM retrieval. For general KSP game mechanics, see ksp-world-knowledge.skill. For kOS scripting, see kos-programming.skill. For MechJeb integration, see mechjeb.skill.
1. WHAT IS KRPC?
kRPC (Kerbal Remote Procedure Call) is a mod framework that allows external programs to control Kerbal Space Program in real-time via remote procedure calls. It provides a server plugin running inside KSP and client libraries in multiple programming languages.
Key Features:
- Control vessels from external scripts (Python, C#, Lua, Java, C++, Go, Rust, Ruby, Haskell, Node.js, Julia)
- Real-time bidirectional communication
- Low-latency streaming of telemetry data
- Extensible via custom services (add new API endpoints from mods)
- Supports local and network connections
- Integrates with MechJeb, Ferram Aerospace Research, Infernal Robotics, Kerbal Alarm Clock
2. ARCHITECTURE
┌─────────────────────────────────────────────────────┐
│ External Program │
│ (Python / C# / Lua / Java / etc.) │
│ │
│ ┌─────────────┐ ┌─────────────┐ │
│ │ Client API │ │ Stream API │ │
│ └──────┬──────┘ └──────┬──────┘ │
│ │ │ │
└─────────┼──────────────────┼────────────────────────┘
│ gRPC / Protobuf │
▼ ▼
┌─────────────────────────────────────────────────────┐
│ kRPC Server Plugin │
│ (running inside KSP) │
│ │
│ ┌─────────────────────────────────────────────┐ │
│ │ SpaceCenter Service │ │
│ │ (Vessel, Orbit, Flight, Control, Parts) │ │
│ └─────────────────────────────────────────────┘ │
│ │
│ ┌─────────────────────────────────────────────┐ │
│ │ Custom Services (from mods) │ │
│ │ (kRPC.MechJeb, InfernalRobotics, etc.) │ │
│ └─────────────────────────────────────────────┘ │
│ │
│ ┌─────────────────────────────────────────────┐ │
│ │ KSP Game API │ │
│ └─────────────────────────────────────────────┘ │
└─────────────────────────────────────────────────────┘
Communication Protocol:
- RPC Port: 50000 (default) — bidirectional remote procedure calls
- Stream Port: 50001 (default) — continuous data streaming
- Protocol: Protobuf over TCP (default), WebSocket, or SerialIO
3. INSTALLATION & SETUP
3.1 Server Plugin
- Download from GitHub Releases, SpaceDock, Curse, or CKAN
- Install into KSP's
GameData/ folder
- Start KSP, load a save
- Server window appears — click "Start Server" (green light)
Server Configuration (Edit button):
| Setting | Default | Description |
|---|
| Protocol | Protobuf over TCP | Wire format for communication |
| Address | localhost | Network interface to bind |
| RPC Port | 50000 | Remote procedure call port |
| Stream Port | 50001 | Data streaming port |
| Auto-start | false | Start server when KSP loads |
| Auto-accept | false | Accept clients without popup |
3.2 Python Client
pip install krpc
3.3 Other Client Libraries
| Language | Package / NuGet | Status |
|---|
| Python | pip install krpc | Official |
| C# | KRPC.Client (NuGet) | Official |
| Lua | luarocks install krpc | Official |
| Java | krpc-java (Maven) | Official |
| C++ | Client stub generation required | Official |
| Go | github.com/nathan-boulestin/krpc | Community |
| Rust | krpc-mars or krpc-client | Community |
| Ruby | krpc-rb | Community |
| Haskell | krpc-hs | Community |
| Node.js | krpc-node | Community |
| Julia | KRPC.jl | Community |
4. CONNECTION & BASIC USAGE
Connection examples (Python/C#/Lua) and SpaceCenter service API reference extracted to references/core-api.md, covering connection setup, vessel properties, control inputs, reference frames, flight telemetry, and autopilot.
5. CORE API — SPACECENTER SERVICE
SpaceCenter service API reference extracted to references/core-api.md, covering vessel properties table, control inputs, and reference frames.
6. FLIGHT TELEMETRY
Flight telemetry and orbit information code examples extracted to references/core-api.md.
7. AUTOPILOT
AutoPilot usage, configuration, and error reporting extracted to references/core-api.md.
8. STREAMING DATA
Detailed streaming examples extracted to references/streaming-data.md, covering stream creation, polling vs streaming, waiting for conditions, callbacks, and custom events.
9. VESSEL PARTS & RESOURCES
Vessel parts and resources code examples extracted to references/extras.md, covering accessing/controlling parts and resource management.
10. ORBITAL MECHANICS
Detailed code examples extracted to references/orbital-mechanics.md, covering maneuver node creation/execution and Hohmann transfer calculations with Python.
11. WARP & TIME CONTROL
Time warp code examples extracted to references/extras.md.
12. EXTENDING KRPC — CUSTOM SERVICES
C# custom service API and available mod services extracted to references/extras.md.
13. COMPLETE EXAMPLE — LAUNCH TO ORBIT
Full Python launch-to-orbit script extracted to references/launch-to-orbit-example.md, covering gravity turn, coast to apoapsis, burn time calculation, and circularization.
14. COMMUNITY RESOURCES
Community resources, third-party extensions, and quick reference extracted to references/extras.md.
Related Knowledge Bases:
- KSP World Knowledge: ksp-world-knowledge.skill
- kOS Programming: kos-programming.skill
- MechJeb: mechjeb.skill
APPENDIX: QUICK REFERENCE
Connection and stream quick reference extracted to references/extras.md.
