mcp-tcl-udf

This MCP server, TCL-UDf, provides an environment to execute TCL scripts via MCP with safety controls by default. It leverages Molt (memory-safe TCL) to sandbox script execution, and it can also be run with the full TCL runtime if you opt into the unsafe mode. The server also supports managing a network of MCP servers, organizing custom tools, and running Tcl-based tool workflows. You can execute TCL scripts directly, browse and manage available tools, and connect to other MCP servers for orchestration. The built-in tooling includes a TCL script executor (bin__tcl_execute), tool listing (bin__list_tools), and access to Tcl documentation (docs__molt_book), with privileged commands available when you enable privileged mode.

Prerequisites:

• Rust toolchain installed (for building from source) or a Rust-enabled environment to install prebuilt binaries
• Optional: system TCL if you plan to build the unsafe TCL runtime version

Install from crates.io (recommended):

• cargo install tcl-mcp-server
• This will install the tcl-mcp-server binary to your Cargo bin path

Run the server (default Molt safe runtime):

• tcl-mcp-server

Build from source (optional):

• git clone https://github.com/cyberdione/mcp-tcl-udf-server
• cd mcp-tcl-udf-server
• cargo build --release
• ./target/release/tcl-mcp-server

If you want the full TCL runtime (unsafe):

• cargo build --release --no-default-features --features tcl
• ./target/release/tcl-mcp-server

Tip: You can build with both runtimes and switch at startup using --runtime molt or --runtime tcl. See the README for details on runtime selection.

Environment and runtime tips:

• Runtime selection: You can choose Molt (safe) or TCL (unsafe) at startup via --runtime molt or --runtime tcl, or via the TCL_MCP_RUNTIME environment variable. CLI args take precedence over environment settings.
• Privileged mode: Start the server with privileged flag to enable script storage and management capabilities. Example: tcl-mcp-server --privileged
• MCP management: Use commands like tcl-mcp-server mcp add/list/ping to manage and verify connectivity with other MCP servers.
• When using the TCL runtime, ensure system TCL installation (8.6+) and development headers if you plan to compile from source.
• If you plan to expose tools or run external scripts, consider using namespace-based tool organization (e.g., bin__, sbin__, docs__ tool naming) to keep tools organized and MCP-compatible.