# Environment Variables
GDAL MCP supports a small set of environment variables to control workspace access and tool registration. Unless stated otherwise, unset variables fall back to their defaults.
## Workspace Scoping
- **`GDAL_MCP_WORKSPACES`** (string, optional)
- **Purpose:** Restrict tool access to a colon-separated allowlist of workspace directories.
- **Example:** `GDAL_MCP_WORKSPACES="/data/projects:/home/user/gis"`
- **Default:** Unset → all paths allowed (not recommended for production).
## Tool Surface Controls
Use these switches to reduce the available tool surface area. Values are case-insensitive and must be explicit.
- **`VECTOR`** (boolean, default: `true`)
- **Purpose:** Enable (`1`/`true`) or disable (`0`/`false`) registration of all vector tools and vector-only resources.
- **Acceptable values:** `1`, `true`, `0`, `false`.
- **`RASTER`** (boolean, default: `true`)
- **Purpose:** Enable (`1`/`true`) or disable (`0`/`false`) registration of all raster tools and raster-only resources.
- **Acceptable values:** `1`, `true`, `0`, `false`.
When a category is disabled, its tools and single-domain resources are not registered with FastMCP. Shared prompts and cross-domain resources remain available.
