Configuration

All configuration is through environment variables on the server entries in your MCP client, for example "env": {"CAVI_SUBSTANCE_WORKSPACE": "/absolute/path"}.

Variable	Server	Default	Meaning
`CAVI_SUBSTANCE_WORKSPACE`	all	`~/Documents/SubstanceMCP`	Asset workspace every tool reads from and writes to
`CAVI_PAINTER_PORT`	Painter	`60041`	Painter's local scripting port
`CAVI_PAINTER_APP`	Painter	standard Adobe installation	Painter app bundle that `runtime start` launches
`CAVI_DESIGNER_BIN_DIR`	Designer	—	Folder holding `sbscooker`, `sbsrender` and `substance3d_baker`
`CAVI_DESIGNER_APP`	Designer	standard install dir	Designer `.app` path, used when `CAVI_DESIGNER_BIN_DIR` is unset
`CAVI_SAMPLER_BIN`	Sampler	—	Exact Sampler executable
`CAVI_SAMPLER_APP`	Sampler	standard install path	Sampler `.app` path, used when `CAVI_SAMPLER_BIN` is unset
`CAVI_SAMPLER_SCRIPT_PATH`	Sampler	Sampler's per-user scripts folder	Startup-scripts folder that `sampler_status` reports

Workspace#

The default workspace is created the first time a tool writes to it. A workspace you set yourself must already exist; a missing one is refused instead of created. Read-only tools never create it; the one exception is that a Sampler call holds its lock file in the workspace, so it creates the default first. Inputs and outputs stay inside it, including through symbolic links. Export and copy operations require a new destination directory and refuse existing ones. All three servers share the one workspace, so the output of one application is an input to the next.

Painter connection#

Connections use 127.0.0.1 directly, without HTTP proxies or redirects. See the Security model.

Application discovery#

Designer binaries: CAVI_DESIGNER_BIN_DIR, else CAVI_DESIGNER_APP, else the standard

install dir for macOS, Windows or Linux, else sbsrender on PATH. An override is final: a wrong one is reported as not found, not replaced.

Sampler executable: CAVI_SAMPLER_BIN, else CAVI_SAMPLER_APP, else the standard

install path for macOS, Windows or Linux, else the executable on PATH. Each Sampler launch also sets Adobe's own SAMPLER_SCRIPT_PATH for the Sampler it starts; that variable is Adobe's, not ours.