AI assistants in AutoCAD and Civil 3D
CAD Bridge
Connect your AI assistant to the drawings open in AutoCAD and Civil 3D. It reads them, checks them and, when you approve, builds in them.
- Free
- Runs on your computer
- AutoCAD and Civil 3D 2023–2027
How it works
Your assistant, your drawing, and you in between
The CAD Bridge has two parts, both on your computer: a server your assistant talks to, and an add-in inside the CAD application that carries out what you allow.
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Your AI assistant
Asks for what it needs: a listing, a sample of the surface, a design step.
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The CAD Bridge server
A local server with 135 tools. It reaches the add-in through a pipe only your Windows account can open.
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AutoCAD or Civil 3D
The CAD Bridge tab: Connect, Edit mode, and a dialog for every change before it is made.
Works with
The assistant you already use
The CAD Bridge speaks the Model Context Protocol, so desktop apps, command lines and code editors can reach it. Its installer finds the ones on your computer and sets them up.
Claude
Claude Desktop, Cowork and Claude Code.
ChatGPT and Codex
The Codex command line, and the Codex mode of the ChatGPT desktop app.
Gemini
The Gemini command line and Google Antigravity.
Your code editor
VS Code with GitHub Copilot, and Cursor.
Or ask inside CAD. The AI Assistant palette in AutoCAD and Civil 3D works with your provider's key, a subscription you already have, or a model on your own computer, with a library of ready prompts for common tasks.
What it can do
From reading a drawing to issuing the sheets
Read the drawing
Layers, blocks, text, xrefs and layouts; surfaces, alignments, profiles, corridors, pipe networks, parcels and points; elevations, slopes and volumes, sampled in one call.
Design in one approved step
Six engines build a whole design and check it: road networks with their junctions, building pads, site grading on several levels, driveways, gravity drainage runs and sheet series.
Check the design
Alignments, profiles, corridors, surfaces and networks against the limits you give, sheets as they will plot, and the drawing against your standards.
Calculate
Runoff, time of concentration, pipe hydraulics, detention storage, sight distance, curve K values and COGO, each with its formula and the values it used.
Produce the deliverables
Labels, tables, layouts and PDF sheets, reports for the client, and data shortcuts for the rest of the team.
Remember the job
A record per project keeps its requirements, its criteria and their sources, the stages and the checks, so the next session starts where the last one stopped.
Guidance for civil work
Skills tell your assistant how a civil engineer does each task, which checks belong to it and which sources to quote:
- Road design
- Intersections
- Grading
- Pond design
- Drainage design
- Hydrology
- Stormwater analysis
- Earthworks quantities
- Quantity takeoff
- Setting out
- Site planning
- Erosion control plans
- Design checks
- As-built conformance
- Sheet production
- Drawing clean-up
- Standards
- Client reports
Safety
Nothing changes in your drawing without you
The CAD Bridge was designed for production drawings. A CAD manager can check every one of these:
- Nothing listens until you click Connect in the CAD Bridge tab.
- Edit mode is off every time AutoCAD or Civil 3D starts.
- Changes go only to the sandbox, the project folders you list, or a drawing you trust.
- Each change shows in a dialog in CAD: allow it once, for the session, or refuse it.
- The drawing is backed up before the first change of a session.
- Each change is one transaction, so one UNDO takes it back.
- Every call is written to a monthly log you can read.
- Keys are encrypted for your Windows account, and nothing is sent to us.
Requirements
What it needs
Your computer
- CAD
- AutoCAD or Civil 3D 2023, 2024, 2025, 2026 or 2027; other AutoCAD-based products get the AutoCAD tools
- Windows
- Windows 10 or 11, 64-bit
- Installation
- For you alone, with no administrator rights; nothing else to install
Your assistant
- Assistant
- A desktop app, command line or code editor that supports the Model Context Protocol
- Or the palette
- A provider's key, a subscription you already have, or a local model
- Price
- The CAD Bridge is free
Try the CAD Bridge on your own drawings
It is free. Tell us a little about your work and we will send you the installer.