DraftCAD AI Assistant: Draw 2D CAD with Claude

Where it lives

Open any drawing from `/drafts` and click the ✨ assistant button in the bottom-right corner (or press **Cmd+K** from anywhere in the editor) to open the chat panel. Type a prompt, press Enter, and the assistant starts drawing. Press **Esc** to cancel a run in progress; the panel collapses to a small launcher with a live badge so you can keep drafting while it works.

The panel shows each step as it happens, a running log of the tools the assistant calls, a live cost meter, and the agent's short notes on what it is doing, so you always see how the drawing is being built.

What you can ask it to draw

**Geometry** — lines, polylines, rectangles, circles, arcs, regular polygons, ellipses, and points. Ask for a room outline, a wall run, a bolt-hole circle pattern, a window break, and it places the geometry to the coordinates and sizes you give it.

**Annotation** — linear, aligned, radial, diameter, and angular **dimensions**; **text** labels; **leaders** for callouts; and **hatches** (solid fill or patterns like ANSI31, brick, cross) to poché cut walls or mark materials.

**Organization** — it can create and switch **layers** (walls on one, dimensions on another), recolour and re-layer existing entities, and insert **blocks** you have already defined.

**Editing** — point it at existing geometry to **move, copy, rotate, scale, mirror,** or **delete** it. "Copy this window three times at 1200 mm spacing", "rotate the stair 90 degrees", "mirror the layout across the centre line".

Live, on your canvas, fully undoable

Each tool the assistant calls lands on your drawing immediately, you watch walls, dimensions, and hatches appear in real time rather than waiting for a finished result. Because every entity it draws is native DraftCAD data, you can grab a grip, change a layer, retype a coordinate, or run any normal command on it the moment it appears.

Every action is recorded as a standard undo step. **Undo** once to remove the last thing it drew, or use the panel's undo control to roll back the whole run. Nothing the assistant does is special or locked, it is your drawing, drawn faster.

It knows how to draft

The assistant carries a library of **drafting skills**, short reference files it loads on demand when your prompt calls for them: architectural drafting conventions (layer naming, lineweights, standard wall, door, and window sizes), dimensioning standards (chains, offsets, text height by scale), hatching and poché, residential floor-plan archetypes (room sizes and clearances), and title-block / sheet layout.

You do not load skills manually, the assistant decides when one is relevant. Ask for "a two-bedroom apartment plan" and it pulls the floor-plan archetypes (realistic room sizes, door widths, clearances) before it starts drawing, so the result is to scale and conventional, not a rough guess.

Powered by Claude, your API key

The assistant runs on Anthropic's **Claude** models. A toggle in the panel switches between **Fast** (Claude Sonnet, cheap and good for most drafting) and **Premium** (Claude Opus, slower and more capable for complex, multi-part drawings).

AI features use your personal **Anthropic API key**, the same one DraftCAD's other AI tools use. Add it once at **Profile → AI features**; it is encrypted on our server with AES-256-GCM using a per-user secret and only ever decrypted in memory for the duration of a single call. The plaintext key never returns to your browser, and you can remove it any time.

Typical cost is a few US cents per drafting session. We use prompt caching aggressively, the system prompt, loaded skills, and conversation history all live in Anthropic's ephemeral cache, so follow-up turns are roughly 10× cheaper than the first. The cost meter in the panel shows live totals and the cache-hit ratio, and there is a hard per-session token cap to prevent runaway loops.

Conversational and resumable

Drafting is a back-and-forth. The assistant keeps the conversation going across turns, "now add a window on the east wall", "dimension it", "put the dimensions on a DIMS layer", each refinement builds on what is already there. When a request is genuinely ambiguous (overall size, a mandatory feature), it asks you a short multiple-choice question rather than guessing.

Your session survives a page reload. Come back to the same drawing later and the assistant picks up the conversation where you left off, with its design log rebuilt, so a refresh never loses your thread.

Who it's for

Anyone who would rather describe a drawing than click out every segment: architects and drafters roughing out a plan, students learning CAD, contractors and homeowners sketching a layout to scale, and seasoned AutoCAD users who want a faster first pass before they refine by hand.

The assistant is for structure and speed, getting walls, dimensions, and layers down quickly, while the command line and ribbon stay there for the fine motor work. DraftCAD shares the Home 3D Plan platform with the **[Home Planner](/features/home-planner)** and the **[Modeler 3D Editor](/features/modeler-3d-editor)** (which has its own AI design agent); one free account covers all three.

Frequently asked questions