hileamlakB/PRIMS

PRIMS is a tiny open-source **Model Context Protocol (MCP)** server that lets LLM agents run arbitrary Python code in a secure, throw-away sandbox.
• **One tool, one job.** Exposes a single MCP tool – run_code – that executes user-supplied Python and streams back stdout / stderr.
• **Isolated & reproducible.** Each call spins up a fresh virtual-env, installs any requested pip packages, mounts optional read-only files, then nukes the workspace.
• **Zero config.** Works over MCP/stdio or drop it in Docker.
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Quick-start
1. Local development environment
2. Launch the server
3. Docker
Examples
List available tools
You can use the provided script to list all tools exposed by the server:
Expected output (tool names and descriptions may vary):
Run code via the MCP server
Mount a dataset once & reuse it
This mounts a CSV with mount_file and then reads it inside run_code without re-supplying the URL.
Inspect your session workspace
This shows how to use the **list_dir** and **preview_file** tools to browse files your code created.
Persist an artifact to permanent storage
The **persist_artifact** tool uploads a file from your output/ directory to a presigned URL.
Example (Python):
Download an artifact
Small artifacts can be fetched directly:
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Available tools
| Tool | Purpose |
|---------------------|---------------------------------------------------------------|
| run_code | Execute Python in an isolated sandbox with optional pip deps. |
| list_dir | List files/directories inside your session workspace. |
| preview_file | Return up to 8 KB of a text file for quick inspection. |
| persist_artifact | Upload an output/ file to a client-provided presigned URL. |
| mount_file | Download a remote file once per session to mounts/ . |
See the examples/ directory for end-to-end demos.
Contributing
Contributions are welcome! Feel free to open issues, suggest features, or submit pull requests to help improve PRIMS.