3DE4 Python API

This extension exposes the Waterloo documentation backend for the 3DE4 Python API as a VS Code MCP server definition.

It is intentionally small: the extension does not generate docstrings, validate Waterloo files, or bridge to a separate Python backend. It registers a local wtrl_mcp server definition that points at the bundled Waterloo roots.

Requirements

To use the extension, you need:

• VS Code ^1.115.0 or newer
• sdv-doc-waterloo installed locally so wtrl_mcp is available
• an MCP-capable client such as Copilot Chat or another MCP-aware editor tool

The extension starts wtrl_mcp with this command line:

wtrl_mcp --config vscode/etc/wtrl_mcp.stdio.toml

Features

The extension currently provides one feature:

• a VS Code MCP server definition for the 3DE4 Python API documentation

The server uses these bundled Waterloo roots:

• vscode/roots/tde4_with_examples.wtrl.core.rfc-2119.json
• vscode/roots/tde4_script_config_with_examples.wtrl.core.rfc-2119.json

Recommended

For editing Waterloo docstrings in Python files, install the companion extension:

• Waterloo Docstrings

It provides syntax highlighting and docstring-focused editor support that fits this MCP server.

Use this extension for MCP access to the 3DE4 Python API documentation, and use the companion extension for editing Waterloo docstrings themselves.

Quick tutorial

1. Install the VSIX in VS Code.
2. Make sure wtrl_mcp from sdv-doc-waterloo is available on PATH.
3. Open Copilot Chat or another MCP client.
4. Point the client at the 3DE4 Python API MCP server definition.
5. If the client does not start the server automatically, trigger MCP tool selection once manually. Some clients need that nudge before they start the server process.

Configuration

The extension ships with sensible defaults.

Optional settings:

• tde4.mcpProvideServer: register the MCP server definition in VS Code
• tde4.mcpCommand: override the wtrl_mcp executable name
• tde4.mcpConfigPath: point to a different wtrl_mcp.stdio.toml
• tde4.mcpServerLabel: change the label shown in VS Code

The default configuration file bundled with the extension is:

vscode/etc/wtrl_mcp.stdio.toml

Compatibility

• License: BSD-2-Clause
• VS Code engine constraint: ^1.115.0
• MCP transport: stdio
• Intended backend: wtrl_mcp from sdv-doc-waterloo

The extension is compatible with MCP clients that can consume a VS Code MCP server definition. It does not depend on the older docstring generation or validation commands from the larger Waterloo VS Code package.

Troubleshooting

If activation fails, open the VS Code Output panel and select the channel Channel.3DE4 Python API. The extension prints the preflight result there, including the most common reason: sdv.doc.waterloo is not installed in the Python environment used by wtrl_mcp.