A Model Context Protocol (MCP) server (specification 2025-06-18) for a running
Cuis-Smalltalk image. It is the successor to
the existing RemoteControl HTTP bridge (port 2347) and exposes the image to LLMs and agents over
Streamable HTTP (JSON-RPC 2.0) on port 2357.
RemoteControlMCP lets an MCP client run Smalltalk code in the image, compile methods, take
screenshots and introspect the image – useful for developing Cuis-Smalltalk directly from an
LLM/agent environment (e.g. opencode, Claude Desktop, llama.cpp WebUI).
| Tool | Description |
|---|---|
eval |
Evaluate Smalltalk source in the image. Synchronous until the timeout by default; async: true starts a background job (poll with eval_status). |
eval_status |
Poll the status/result of an asynchronous eval job. |
compile_method |
Compile a Smalltalk method into a class (safelyCompile:classified:), optionally class-side. |
screenshot |
Capture a PNG of the Cuis world (base64), optional crop to a morph class with a pad margin. |
list_classes |
List the names of all classes, one per line. |
class_summary |
JSON summary of a class: superclass, instance variables, method counts and method names. |
image_status |
JSON summary of the running image: name, update level, VM and OS. |
The server also provides one resource (image://status) and one prompt (develop-in-cuis).
"Load the package (requires Cuis 7.8 with the WebClient and JSON packages), then:"
RemoteControlMCP start. "starts the default instance on http://127.0.0.1:2357/mcp"
RemoteControlMCP stop. "stops it again"Packages:
packages/RemoteControlMCP.pck.st– the serverpackages/Tests-RemoteControlMCP.pck.st– unit tests (WebUtilsJsonTest)packages/WebUtils-jsonMapFrom-fix.st– standalone fix for a CuisWebUtilsJSON bugstartup.st– headless start script (RemoteControl 2347 + MCP 2357)
Detailed, up-to-date documentation is provided in several languages. Each guide covers installation,
configuration (port, interface, bearer-token auth, CORS, HTTPS/TLS), usage with curl and from MCP
clients (opencode, Claude Desktop, llama.cpp WebUI), all tools and the error/status codes:
- Deutsch – ausführliche Anleitung mit Beispielen
- English – detailed usage guide with examples
- Español – manual de uso con ejemplos
- Français – guide d'utilisation avec exemples
- 中文 – 使用指南（带示例）
Further references: docs/MCP-Protokoll-Referenz.md (MCP/JSON-RPC spec notes),
docs/Analyse-RemoteControl.md (analysis of the legacy RemoteControl class),
docs/Cuis-Integration-Notizen.md (Cuis-specific findings), docs/Auftrag-Nutzer.md (initial
user request) and docs/WebUtils-jsonMapFrom-Bug.md (a Cuis WebUtils JSON parser bug that was found
and fixed during the opencode integration; the fix is shipped as a class extension inside the
package and covered by Tests-RemoteControlMCP).