SolidBot is a native task pane add-in that turns plain-English requests into verified CAD operations inside SOLIDWORKS: creating parts, editing existing models, detailing, patterning, measuring, drawing, assembling and exporting. It exposes 139 governed chat commands, and 192 governed tool descriptors on its MCP surface, of which 111 change the model and 118 are approval-gated.
The Difference Is What It Refuses to Claim
Most of the engineering went into not overstating what happened:
- Every change is verified, not assumed. A mutation is applied, then read back from SOLIDWORKS and checked against what was asked for. If the read-back disagrees, the change is rolled back and reported as failed. It is never reported as a success with a warning.
- Every change is undoable. Writes run inside a rollback checkpoint of the saved document.
- It says no. A request it has no command for is answered plainly, with the nearest real commands named. It does not guess, and it does not quietly build something else instead.
- Failure is reported as failure. A cancelled run is cancelled, not a product failure. A partially applied sequence names exactly which steps were saved and which never ran.
- It explains what blocked it. When a part fails to build, it measures the geometry responsible and proposes a specific bounded repair, stating the original value, the new value and the physical reason, and applies nothing until you agree.
Governance Built Into the Flow
Execution runs in one of four modes: ReadOnly, PlanOnly, SupervisedWrite and AutoWrite, with an approval gate for supervised writes and a single coordinator handling role authorization, entitlement, mode enforcement and one-time interactive confirmation.
Before anything is written, a plan states its parameters, assumptions, warnings and the exact operations it will run. Every plan carries a human-review disclosure: the output is an AI-assisted design draft, not engineering approval, and a qualified person must verify geometry, dimensions, materials, tolerances, simulation assumptions, manufacturability and release data.
The multi-step planner is deterministic, so sequences run with no AI provider configured at all. The user interface ships complete English, Spanish and Arabic catalogs with machine-governed culture selection and mirrored right-to-left layout.
What It Builds
Current prompt-to-part coverage includes brackets, rectangular plates and blocks, cylinders, OD and ID and length-driven bushings, sleeves and tubes, and concentric stepped shafts with optional axial bores, together with through-holes, cutouts, slots, pads, bosses, linear hole patterns and material assignment. Beyond single parts it does deterministic involute spur-gear synthesis with undercut, backlash, bore-ligament and manufacturing checks, and governed planning across seventeen system archetypes including engines, transmissions, pumps, robots, drones, belt drives, conveyors, linear stages, four-bar and crank-slider mechanisms, process skids and machine tools.
Status, Stated Plainly
It is built and working, with 27 of 28 certification suites green against live SOLIDWORKS 34.1.1, and it is not commercially released. Most of what remains is not code: a code-signing certificate, AI-provider terms with zero-retention conditions, customer IT infrastructure and legal sign-off. We would rather say that than imply general availability.
If CAD automation is on your roadmap, we are happy to walk an engineering team through the tool surface, the policy layer and the audit trail in operation.