Agent Tools

arrange_workbench is Tau's tool for changing what a person sees in the editor. It writes the portable workbench records; the page applies them live when the project is open. The tool is available to Tau's agent and to external agents through Tau Host's MCP endpoint, including Codex in Tau Desktop.

Arrange a view

This input creates a named view of an existing project file and shows it immediately:

{
  "views": [
    {
      "id": "front",
      "name": "Front",
      "entryPath": "main.scad",
      "camera": { "kind": "preset", "preset": "front" }
    }
  ]
}

A view can instead use { "kind": "look", "direction": [0, -1, 0] }; the direction points from the model toward the camera. Other view fields include fieldOfView (0 means orthographic), upDirection, display toggles, grid.unit, section cuts, and pinned measurements. Section and measurement lengths use metres in the model frame. entries changes a file's render timeout and component visibility for all its views.

open adds and activates a view, utility pane, or file tab. A file tab can request markdown preview or source; opening into a hidden workbench lane reveals it. close removes a tab and deletes a closed view's record. viewer and workbench replace their respective group trees when a full arrangement is intended. lanes sets chat and workbench lane intent. Omitted keys retain their current values; a supplied list or lane tree replaces that list or tree. The tool does not control window pixel widths, focus, print approval, physical starts, revision actions, installs, or machine binding.

Preserve the person's arrangement

The per-turn workbench snapshot includes the layout digest and visible state. Pass its layoutDigest as basedOn when the change depends on the arrangement you read:

{
  "basedOn": "sha256:<current-layout-digest>",
  "open": [{ "kind": "file", "path": "docs/review.md", "presentation": "preview" }]
}

The placeholder is the snapshot digest, not literal input. A stale basedOn at the first layout read returns RECORD_CONFLICT before writes; a later per-record checked-write conflict may leave earlier writes. Without basedOn, it rereads and retries conflicts against current bytes. The tool validates paths and records, then writes at the live project root during candidate and MCP turns. An INVALID_RECORD refusal preserves the existing file for correction. The other refusal codes are VALIDATION_ERROR and FILE_NOT_FOUND.

A successful result says status: "written" and lists record paths with their new and previous digests plus the tabs a window will show. written confirms record persistence, which may leave bytes unchanged, rather than that the person has already seen it. The native chat card names the arrangement and shows Written, Shown, or Shown partly; Restore is visible without expanding a disclosure. A debug-only pane such as kernel or console can leave a visible placeholder and appear in the next turn's refused snapshot.

Read External Agents for host setup and Workbench Records for the package codecs and file shapes.