classcad.ai

AI-driven,
verified,
embedded
CAD.

Describe a part in plain language. An agent writes a ClassCAD program, runs it live, proves the result, and hands you a model that lives inside any app. Scroll through it: every picture on this page is drawn live, by the same code that renders the film.

An agent is told: agent, look at classcad.ai and install the mcp. It reads llms.txt, adds the classcad server, and signs in once through classcad.ch. In a new session it is asked for a minimal, simplified flanged bushing: it sketches one profile and revolves it into a Ø80 × 10 mm flange with a Ø50 hub, 50 mm tall and bored Ø30 through, checks the volume (93,457 mm³) against the math and shows a snapshot. The session's CAD app then comes up beside the conversation, with the part and its history in it: the part is turned, and its rollback bar is pulled back over the revolve, to the sketch, and let go again.
agent, look at classcad.ai and install the mcp

Agents: the steps are in /llms.txt.

Or add it by handClaude Code · Claude Desktop · Codex · VS Code · Cursor · OpenCode

in a terminal

claude mcp add classcad --scope user -- npx -y @classcad/mcp@latest
01 Describe · 02 Execute · 03 Verify · 04 Share · 05 Embed · 06 Anatomy Scroll

01 · Describe

Describe it.

Plain language in. Verified geometry out.

› ↵

Thinking…

  1. docsv1.solid.* · recipes/direct-modeling-eif · recipes/verification
  2. run_scriptwriting the program

02 · Execute

One way to execute.

The agent writes a program. ClassCAD runs it live.

run_scriptlive ClassCAD session

    Constrained sketches, dimensions, expressions.

    ClassCAD solves the constraints. Dimensions bind to named expressions, so one value drives the whole shape, and the agent knows how to set them up.

    It returns the model, not a status.

    return
    
              
    api.tree()
    
              
    api.graphic()
    
            
    
          
    
        
    

        
        
    
          
    
            
    03 · Verify
    
            
    Verification is built in.
    
            
    Proof by numbers and deterministic renders, not status codes.
    
          
    
          
    
            
      
              
    • view: 'iso'
      • 
              
    • lines: true
      • 
              
    • section: { origin, normal }
      • 
              
    • highlightAt + markers
      • 
              
    • drawing: 'first-angle'
      • 
            
    
            
    
          
    
        
    
        
    
          
    
            
    
              
    calculateMassProperties()
    
              
    volume18 338.53mm³✓
    
              
    cog−0.11 · −0.20 · −0.13✓
    
              
    extents44.4 × 44.1 × 34.6✓
    
            
    
          
    
        
    

        
        
    
          
    
            
    04 · Share
    
            
    One link, and it travels.
    
            
    
              The session’s CAD app comes up under a share link. Send it to a colleague, or open it on another device:
              whoever has it is in the same session.
            
    
          
    
          
    
            
    Everyone sees the same model.
    
            
    Each from their own side. Where one of them points, or what they select, shows for all the others.
    
          
    
          
    
            
    A change lands for all, at once.
    
            
    People and agents work on one model: they turn it, select in it, and edit it together.
    
          
    
          
    
            
    It stays on your machine.
    
            
    The engine and the model run where the agent does. The relay keeps nothing: no model, no account, no log.
    
          
    
        
    

        
        
    
          
    
            
    05 · Embed
    
            
    Part of any app.
    
            
    
              Traditional CAD bolts dialogs onto its own modeler. ClassCAD is a headless engine that runs
              inside your product.
            
    
            
    
              Take your agent’s script, add it to your product and change parameters live. Or bring the agent along: our in-app
              assistant works with your own AI provider.
            
    
          
    
          
    
            
    
              
    runs as
    cross platform C++WebAssembly
    
              
    API wrappers
    JavaScript · Node.jsPython.NET
    
              
    deploys to
    webserverclouddesktopmobile
    
            
    
          
    
          
    
            
    Change it live.
    
            
    
              
    your app@buerli.io/react
    
              
      
                
    1. const { api, Geometry } =
      2. 
                
    2.   useBuerliCadFacade('with-claude-sprocket')
      3. 
                
    3. useEffect(() => {
      4. 
                
    4.   updateSprocket(api, { teeth: 13, strands: 2 })
      5. 
                
    5. })
      6. 
                
    6. return <Canvas><Geometry /></Canvas>
      7. 
              
    
            
    
          
    
        
    
      
    
    
    

    
    
    
      
    06 · Anatomy
    
      
    Four branches, one repository.
    
      
    What knows the API, what runs the program, what proves the result, and where the agent lives. Every package is open on GitHub.
    

      
      
    
        
    classcad-ai
    
        
    
          
    
            
    Knowledge
    
            
    The Skill
    @classcad/skill
    every method of the API, verified, and its recipes
    
            
    Discovery
    @classcad/skill/discovery
    search, describe, and the docs tool
    
          
    
          
    
            
    Execution
    
            
    The Script
    @classcad/script
    one way to execute: a program, run_script
    
            
    The Engine
    classcad-cli · wasm
    ClassCAD itself, on a worker or in the page
    
          
    
          
          
    
            
    
              
    classcad-cli
    
              
    worker · ws://localhost:9094
    
              
    on your machine, in Docker, or hosted
    
              download
            
    
            
    
              
    ClassCAD WASM
    
              
    in the browser, or inside the MCP
    
              
    the same engine, no server
    
            
    
          
    
          
    
            
    Proof
    
            
    The Renderer
    @classcad/renderer
    views, drawings, sections and diffs
    
            
    The Numbers
    the engine
    mass properties and geometry probes
    
          
    
          
    
            
    Hosts
    
            
    The MCP Server
    @classcad/mcp
    Claude Code, Codex, OpenCode, Cursor, VS Code
    
            
    The In-App Agent
    @buerli.io/ai
    a chat panel in buerli apps
    
          
    
        
    
      
    

      
    
        
        
    
          
    
            
    Knowledge · @classcad/skill
    
            
    The knowledge.
    
            
    
              The ClassCAD API, whole: 264 methods, each documented and verified against a
              live engine, and the recipes that combine them into parts and assemblies. One search serves it all: BM25-ranked,
              camelCase split, plurals folded, and fluent in CAD.
            
    
            Seen in 01 Describe: the agent reads the docs ↑
          
    
          
    
            
    
              
    Methods, by domain
    
              
      
                
    1. part76
      2. 
                
    2. assembly63
      3. 
                
    3. sketch50
      4. 
                
    4. common22
      5. 
                
    5. curve21
      6. 
                
    6. solid21
      7. 
                
    7. drawing2d11
      8. 
              
    
              
    In all264
    
            
    
            
    
              
    Recipes
    
              
      
                
    1. § 1Constrained sketching
      2. 
                
    2. § 2Verification
      3. 
                
    3. § 3Parametric parts
      4. 
                
    4. § 4Assembly parameters
      5. 
                
    5. § 5Pattern, then subtract
      6. 
                
    6. § 6Direct modelling
      7. 
              
    
              
    One search
    
              
    holeis abore
    
              
    roundis afillet
    
            
    
          
    
        
    

        
        
    
          
    
            
    Execution · @classcad/script
    
            
    The medium.
    
            
    
              An agent never dictates one call per turn. It writes a program, with variables, loops and geometry filtered by
              plain arithmetic, against api.v1, api.tree() and api.graphic(), and runs
              it through run_script: the same in the browser, in the MCP and in Node.
            
    
            
    browser · @buerli.io/aiMCP · classcad-mcpNode · runScript
    
            Seen in 02 Execute: the sprocket's program ↑
          
    
          
    
            
    
              
    a scriptrun_script
    
              
      
                
    1. const { result: part } =
      2. 
                
    2.   await api.v1.part.create({ name: 'Plate' })
      3. 
                
    3. await api.v1.part.box({
      4. 
                
    4.   id: part, length: 80, width: 50, height: 10 })
      5. 
                
    5. const { result: { volume } } = await api.v1
      6. 
                
    6.   .part.calculateMassProperties({ id: part })
      7. 
                
    7. return { part, volume }
      8. 
              
    
            
    
            
    returns{ part: 4, volume: 40000 }
    
            
    
              
    and runs it@classcad/script/node
    
              
      
                
    1. import { connectSession, runScript } from '@classcad/script/node'
      2. 
                
    2. const session = await connectSession()  // a classcad-cli worker, :9094
      3. 
                
    3. const res = await runScript(script, session)
      4. 
                
    4. // res → { ok: true, returned: { part: 4, volume: 40000 } }
      5. 
              
    
            
    
          
    
        
    

        
        
    
          
    
            
    Proof · @classcad/renderer
    
            
    The eyes.
    
            
    
              Images of the live model, the same every time: no GPU, no camera state. Named views and turntable cameras;
              technical drawings in either projection, hidden edges dashed; sections capped and hatched; highlights, probe
              markers and pixel diffs.
            
    
            
    iso viewslineshidden edgessectionsx-raydrawingsmarkerspixel diffs
    
            Seen in 03 Verify: iso, lines, section, markers, drawing ↑
          
    
          
    
            
























from below
from the right
front
from the left
from behind
from above
            
    
              
    The two methods
    
              
    




    First-angleISO E · Europe
    
              
    




    Third-angleISO A · the Americas
    
            
    
          
    
        
    

        
        
    
          
    
            
    Hosts · @classcad/mcp · @buerli.io/ai
    
            
    The envoys.
    
            
    
              Two envoys make the part: the MCP server, which serves any agent host and joins any ClassCAD app, or works
              on its own; and the assistant, which lives inside the app, with any tool-calling LLM.
            
    
            Seen in 05 Embed: the part inside an app ↑
          
    
          
    
            
    
              
    Any MCP host
    
              
    
                
      
                  
    • Claude Code
      • 
                  
    • Codex
      • 
                  
    • OpenCode
      • 
                  
    • Claude Desktop
      • 
                  
    • VS Code
      • 
                  
    • Cursor
      • 
                
    
                
                
    mcpone daemon 
    per machine
    
                
                
      
                  
    • On its owna worker, or its own WASM
      • 
                  
    • Joins any ClassCAD appby invite
      • 
                
    
              
    
            
    
            
    
              
    The in-app assistant
    
              
    
              
    
                
    Make a flanged bushing.
    
                
    Done: a 60 mm flange with a flat, a 30 mm hub, bolt holes and a port.
    
              
    
              
    
                
    your ClassCAD app
    
                

















              
    
              
    
            
    
          
    
        
    
      
    

      
    
        ClassCAD documentation →
        classcad-ai on GitHub →
      
    
    
    

    
    
    
      
    
        
    07 · FAQ
    
        
    Your work stays yours.
    
        
    Who owns what you make, what reaches AWV, and what you pay.
    
      
    
      
    
        
    
          Do I own my prompts, models and designs?
          
    Yes. Between you and AWV, your prompts, CAD models, drawings, generated code and inventions are yours. AWV claims no ownership of them.
    
        
    
        
    
          Does AWV get a license to my content?
          
    No. Using the skills and recipes of ClassCAD.ai, or the ClassCAD software, gives AWV no license to your content.
    
        
    
        
    
          Is my content used to train AI models?
          
    Not by AWV. We don't receive your prompts, CAD files or design data, and don't use them for training. Whether your AI provider does depends on its terms and your account settings.
    
        
    
        
    
          Is my content passed on to AI providers?
          
    Not by AWV, which neither receives nor forwards it. When you use an AI assistant with ClassCAD, the AI service you chose processes your prompts and any CAD information given to it.
    
        
    
        
    
          Can AWV employees see my content?
          
    No. AWV doesn't receive or store your prompts, CAD files or design data when you work with ClassCAD.ai, so no one at AWV has access to them.
    
        
    
        
    
          How long are my prompts and CAD files kept?
          
    AWV keeps none. When ClassCAD runs as WebAssembly in your browser, CAD processing happens on your machine. If you host ClassCAD yourself, you decide on storage and retention. Your AI service keeps content according to its own terms and your settings.
    
        
    
        
    
          Can my content be deleted for good?
          
    AWV holds no copy to delete. You control deletion on your machine or your own servers. Content held by your AI service follows that provider's deletion options and retention rules.
    
        
    
        
    
          Is my content kept confidential?
          
    AWV doesn't receive your design content when you work with ClassCAD.ai. It stays in your CAD environment and with the AI service you give it to; confidentiality there depends on your agreements with those providers.
    
        
    
        
    
          Do I owe anything when I sell a product designed with ClassCAD?
          
    Selling a product designed using ClassCAD does not create any royalty, revenue-sharing, attribution or license-back obligation to AWV. You do not need to maintain a ClassCAD subscription solely to continue manufacturing or selling that product.
    
          
    An active commercial ClassCAD license is required to continue using ClassCAD commercially, including working with native OFB models. OFB files can be opened in the free version, but that version may not be used commercially.
    
          
    Exported STEP files remain usable in compatible CAD software independently of your ClassCAD subscription. If you plan to end your subscription, export the models you need as STEP files beforehand.
    
          
    A “Powered by ClassCAD.ai” mention is appreciated but entirely optional.
    
        
    
        
    
          What does ClassCAD.ai cost?
          
    The skills, the recipes and the MCP server are free. You pay for the ClassCAD engine they drive, with a plan at classcad.ch: Free covers private use and evaluation; Solo, Pro and Business add commercial work, STEP and other exports, live sharing, apps on your own domains and self-hosting. AI usage is billed by your AI provider, and AWV gets no share of it.