Use SpeakCAD from ChatGPT, Claude and other AI assistants
Assistants are good at understanding what you need and bad at producing a file that prints. The SpeakCAD connector splits the work: the assistant gathers the measurements, SpeakCAD's own AI builds the dimensioned model in your SpeakCAD account, and you get the STL, 3MF or G-code for your printer without leaving the conversation. The part stays in your models, one click from the full editor.Setting it up, click by click: SpeakCAD in ChatGPT and SpeakCAD in Claude. This page is the overview; SpeakCAD for ChatGPT, SpeakCAD for Claude and the MCP server sum up what each one does and costs, with the set-up for Claude Code, Cursor and VS Code.
What the connector does
MCP (Model Context Protocol) is the standard ChatGPT, Claude and other assistants use to talk to outside tools. The SpeakCAD server gives the assistant these, all on your signed-in account:
- search_models and get_model look through the library of generate-to-fit parts and the maker marketplace; in Claude a ready-made model shows in 3D.
- create_part has SpeakCAD's AI design a new part from the description and measurements, as a new model in your account. It is the same AI, the same model routing and the same design rules as the editor on the site.
- edit_part changes it in words, one change at a time, each a new version; get_part reads where it stands, its size and its named dimensions.
- edit_file changes your own STL or 3MF: a file cannot go through the chat, so the SpeakCAD card opens in the conversation, you drop the file on it and type the change, and SpeakCAD's AI changes it in your account (a request's credits); after that it is a part like any other for edit_part, the downloads and the slicer.
- download_part gives an STL or 3MF link, priced as a download on the site (included in every plan).
- find_printer and prepare_slice pick your printer among 380+ from 60+ brands and the print settings, checked against its OrcaSlicer profile; the part (or a file you drop) is sliced in the conversation and the G-code comes back as a link.
- get_account and get_pricing tell the assistant what you have left and what things cost, so it quotes the right price.
The slicer tools also come on their own, as the SpeakCAD Slicer connector at https://speakcad.com/api/mcp/slicer, listed in Claude's connectors directory: see slice from ChatGPT or Claude.
Inside Claude: the part in the conversation
Claude renders interactive tools, and SpeakCAD uses that: the part appears in the chat in 3D while SpeakCAD designs it, then with its dimensions as number fields. Change a number and apply it (free, a new version), type a change in words, download the STL or 3MF, or slice it for your printer and download the G-code, all in the card. The assistant is told the result, so you can keep talking about it. The Open in SpeakCAD button opens the same part in the full editor.
Why the editor is still one click away
The chat is the quickest way to a first version. The editor is where a part gets right: you click the face or the hole you mean and describe the change, every version is kept and can be restored, and Fit Check prints a five-minute test piece that calibrates the clearances to your own printer. Everything made from the chat is already in your models there.
What it costs
Exactly what it costs on the site, from the same balance: 4 credits per new part on a plan, its first 3 small changes free (3 without a plan), 3 per design change (2 for a small change, 1 for a quick tweak such as a changed number), downloads included in every plan (4 credits without one), and G-code at the price of the STL. A plan pays for it, from Maker at $7.99 a month; Unlimited includes the requests. Typing new dimensions and looking at the part in 3D spend nothing. Adding the connector is free; it needs a SpeakCAD account to sign in.
No connector? Paste the description
The connector is a convenience, not a requirement. When the assistant has already written the part (the sizes, the holes, the lid) copy that text, open SpeakCAD and paste it into the chat: the numbers are used exactly. The ChatGPT to STL page shows what to keep from the conversation and what comes out.
Why not let the assistant write the model itself
Assistants will happily write OpenSCAD or describe a shape, and the result usually needs a CAD tool, a fix for a non-manifold mesh, and a slicer. SpeakCAD compiles the model in the browser, applies FDM design rules (wall thickness, clearances, a flat base), shows it in 3D, and exports a watertight file, or G-code for your exact printer. The assistant is the front door; the editor is where the part gets right.
Good requests
Give measurements in millimetres and say what the part mates with: "an enclosure for a 70 x 50 mm PCB with four M3 holes on a 62 x 42 mm pattern, a USB-C cutout on the short side, 2 mm walls and a snap-fit lid". The assistant passes all of it along, and the numbers are used exactly.
Invite a friend while you are at it
Every SpeakCAD account has an invitation link on its plan page. A friend who subscribes from it gets extra credits, and so do you, more on a higher plan.
- 1Add the connectorThe SpeakCAD MCP server is at https://speakcad.com/api/mcp. In Claude: Customize, Connectors, +, Add custom connector, paste the address. In ChatGPT: turn on Developer mode in Settings, Security and login, then press + on the Plugins page and paste the address, with OAuth. Any other MCP client works the same way, with the Streamable HTTP transport and OAuth.
- 2Sign in with your SpeakCAD accountThe assistant opens SpeakCAD's sign-in page and asks you to allow it. Everything it does is saved in your account and paid with your credits, exactly as on the site. You can disconnect it at any time from the assistant's connector settings.
- 3Describe the partSay what you need with its measurements: a case for a Raspberry Pi 5 with a fan cutout, a hook for a 40 mm pipe. The assistant checks the SpeakCAD catalogue first, then has SpeakCAD design the part; it usually takes two to five minutes and, in Claude, appears in 3D in the chat.
- 4Adjust itType new dimensions in the viewer (free, saved as a new version) or ask for a change in words, in the chat or in the viewer (2 credits for a small change, the first 3 of each part free on a plan, 3 for a design change, included in Unlimited).
- 5Download or sliceDownload STL or 3MF (included in every plan; 4 credits without one, with small fixes of a paid design re-downloading free), or G-code sliced for your printer (at the price of the STL). For click-to-select edits, every version and Fit Check, open the part in the SpeakCAD editor.