Mass budget from an Onshape Part Studio
This reads a Part Studio, not an assembly tree. The report says so before it says anything else, because a partial total that looks complete is worse than no total.
The problem this solves
Mass data lives in CAD and the budget lives in the model, and the gap gets closed by someone reading numbers off a screen once a quarter. Automating it is only an improvement if the automation is honest about what it could not see, and about which masses had no material behind them.
How it works
Part properties by FeatureScript evaluation, with the Part Studio scope stated before any total. The connector reaches a Part Studio, not an assembly tree, so coverage is usually partial and the report leads with that rather than presenting a partial total as a complete one.
About this connector
The Onshape connector is pointed at a configured document and Part Studio.
The Onshape connector is a FeatureScript environment. It reads and writes Feature Studios and evaluates FeatureScript against a Part Studio in a configured document. Geometry and mass data are reachable by evaluating FeatureScript, but this is not an assembly or BOM connector, and these workflows are scoped to a Part Studio in the configured document rather than to a full assembly tree. If you need assembly-level rollups today, this connector cannot do it.
The prompt
You are reading part properties from an Onshape Part Studio by evaluating FeatureScript, and using them to update the mass budget in the Dalus model [model name]. READ THE CONNECTION'S LIMITS INTO THE CONVERSATION FIRST. This connector evaluates FeatureScript against the configured document's Part Studio. It is not an assembly BOM interface. Tell the user plainly what is in scope: the parts in the Part Studio you can reach, not a full assembly tree, and not other documents. If what they need is an assembly rollup, say the connector cannot do it today rather than producing a partial total that looks complete. CHECK THE CONNECTION FIRST: confirm the configured document and Part Studio, report what you can see, and confirm the Dalus model is reachable. Before writing any FeatureScript, read the existing FeatureScript notes and the documentation search, since the API surface matters more here than in any other workflow in this library. CONFIRM FIRST, in one message: which Dalus model and branch; which Part Studio; which properties to collect (mass, volume, material, bounding box); how parts map to model parts; and whether a previous run exists to compare against. Ask anything else in the same message. Then begin. TREAT THE DOCUMENT AS READ-ONLY. Evaluate FeatureScript to query; never write a Feature Studio, never create geometry, never modify the user's parts. Use the test evaluation path rather than anything that persists. EVALUATE AND EXTRACT: query the parts in the Part Studio and return per part its name, part number or attribute where set, mass, volume, material and density. Print structured output that you can parse reliably rather than prose. If an evaluation errors, report the error verbatim and do not substitute an estimate. MATERIAL HONESTY: a mass computed with no material assigned, or with a default density, is not evidence. Report those parts separately and exclude them from the headline total rather than absorbing them into it. MATCH PARTS TO MODEL PARTS and show the matching basis per item, marking inferred matches, with unmatched items in their own lists on both sides. ROLL UP through the model hierarchy with the arithmetic visible, children summing to parents. State coverage next to every total: what share came from parts with real materials, what share is unassigned, and what share of the model has no Onshape source at all. Given the Part Studio scope, coverage will often be partial, and the report must lead with that rather than bury it. REPORT THE MARGIN against the allocation with its requirement ID, in absolute terms and as a percentage, and the delta against a previous run where one exists. OFFER, DO NOT EXECUTE: writing the masses onto model parts as attributes, gated per part, with their material provenance; and re-running before the next review. THIS WORKFLOW IS READ-ONLY on the Onshape document and on the Dalus model unless the user approves the write-back per part.
Replace the [bracketed] placeholders with your model and project names.
What you get
Evaluates FeatureScript to query parts, using the test evaluation path rather than anything that persists: it never writes a Feature Studio, creates geometry, or modifies your parts. An evaluation error is reported verbatim rather than filled with an estimate.