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ChatGPT plugin for 3D printing
Design 3D printable parts in ChatGPT, then download the STL or G-code
SpeakCAD for ChatGPT is a 3D printing plugin. You describe a part in the chat with its measurements; ChatGPT hands it to SpeakCAD's own CAD AI, and the part comes back in 3D in the conversation, with its dimensions to adjust and a print-ready STL, 3MF or G-code sliced for your printer (380+ printers). ChatGPT keeps the part it is good at, the questions; SpeakCAD does the geometry, the print rules and the file, on your SpeakCAD account exactly as on the site.How it works
From a conversation to a part on the print bed
Five steps, the first two once. The setup, click by click, is in the SpeakCAD in ChatGPT guide.2
Sign in with your SpeakCAD account
ChatGPT opens SpeakCAD's sign-in page; sign in (or create the account there) and press Allow. Parts are saved in your account and paid with its credits: add Starter credits ($5 once, 50 credits) or a plan before the first one.3
Ask for the part
Type @SpeakCAD, or pick SpeakCAD in the + menu, and describe the part with its measurements. Missing a number? Let ChatGPT ask you first: its questions are what make the first version right.4
See it in 3D and adjust it
One to two minutes later the part shows in the SpeakCAD card with its size and named dimensions. Type a new value (free, a new version) or ask for a change in words (2 credits).5
Download the file or the G-code
STL or 3MF (10 credits), or name your printer and get G-code sliced with its OrcaSlicer profile (5 credits more, included in Pro and Unlimited).ChatGPT with SpeakCAD vs ChatGPT on its own
| ChatGPT + SpeakCAD | ChatGPT on its own | |
|---|---|---|
| Works out what the part needs | Yes: ChatGPT asks, then hands SpeakCAD one complete description | Yes |
| Builds the model | SpeakCAD's CAD AI writes a parametric program, compiled into exact geometry | Writes OpenSCAD or a description; at best a basic STL of a simple shape |
| Shows the part | In 3D in the chat, with its size and named dimensions | No render: you read code or text |
| Print rules | Wall thickness, fit clearances and a flat base applied | Only if you ask, and nothing checks them |
| Changing a size | Type the number in the card (free) or say it in one sentence | Ask again and rebuild the file yourself |
| The file | Watertight STL or 3MF, or G-code for 380+ printers | Code to compile and slice elsewhere |
| Where the part lives | In your SpeakCAD models, one click from the full editor | In the chat history |
| Cost | SpeakCAD credits, as on the site (2 credits a request, 10 credits a download) | Your ChatGPT plan |
Works out what the part needsChatGPT + SpeakCAD: Yes: ChatGPT asks, then hands SpeakCAD one complete descriptionChatGPT on its own: Yes
Builds the modelChatGPT + SpeakCAD: SpeakCAD's CAD AI writes a parametric program, compiled into exact geometryChatGPT on its own: Writes OpenSCAD or a description; at best a basic STL of a simple shape
Shows the partChatGPT + SpeakCAD: In 3D in the chat, with its size and named dimensionsChatGPT on its own: No render: you read code or text
Print rulesChatGPT + SpeakCAD: Wall thickness, fit clearances and a flat base appliedChatGPT on its own: Only if you ask, and nothing checks them
Changing a sizeChatGPT + SpeakCAD: Type the number in the card (free) or say it in one sentenceChatGPT on its own: Ask again and rebuild the file yourself
The fileChatGPT + SpeakCAD: Watertight STL or 3MF, or G-code for 380+ printersChatGPT on its own: Code to compile and slice elsewhere
Where the part livesChatGPT + SpeakCAD: In your SpeakCAD models, one click from the full editorChatGPT on its own: In the chat history
CostChatGPT + SpeakCAD: SpeakCAD credits, as on the site (2 credits a request, 10 credits a download)ChatGPT on its own: Your ChatGPT plan
What you can ask
SpeakCAD is for functional parts with real measurements: enclosures for a PCB or a Raspberry Pi, brackets, wall mounts, holders, adapters, organizers, replacement clips and knobs. Requests that work as they are:
- “Use SpeakCAD to design a wall mount for my Wi-Fi router: it is 180 x 120 x 35 mm, the cables come out of the back, and it hangs on two screws 100 mm apart.”
- “Design a case for a Raspberry Pi 5 with SpeakCAD: 2 mm walls, a 30 mm fan cutout in the lid, openings for the USB-C, both micro-HDMI and the Ethernet port, and four rubber feet pockets.”
- “I need a hook for a 40 mm round pipe that holds a 2 kg bag. Ask me what you need to know, then design it with SpeakCAD.”
- “Make the walls 3 mm and add a 5 mm hole in the centre of the lid.”
- “Slice it for my Bambu Lab A1 in PETG, 0.2 mm layers, 30% infill.”
Good requests share three things: measurements in millimetres, what the part fits or holds, and how it attaches. How to describe a part has templates.
What ChatGPT can do with SpeakCAD
- Design a part from a description with its measurements, in about one to two minutes, as a new model in your SpeakCAD account.
- Change it in words, one change at a time; each change is a new version and earlier ones are kept.
- Read where it stands: its size, its named dimensions and SpeakCAD's note on the last change.
- Give you the file: an STL or 3MF download link, or G-code sliced for your printer, with the print time and filament weight.
- Find a ready-made part in the SpeakCAD library and the maker marketplace.
- Check your balance and what things cost, so it quotes the right price.
The part is the same as one made on speakcad.com: the same AI, the same design rules, the same price. Open in SpeakCAD editor opens it there, where you click a face to change it, every version is kept, and Fit Check prints a five-minute test piece that calibrates clearances to your printer.
Plugin, app, connector, MCP: one server
OpenAI calls them plugins (they were apps until mid-2026); Claude calls them connectors. Under both names, SpeakCAD is one MCP server (Model Context Protocol, the open standard assistants use to call outside tools) at https://speakcad.com/api/mcp. The same server works in Claude and in other MCP clients, and the parts you make from one show up in the others, because they all live in your SpeakCAD account.
Which ChatGPT plans
Connecting SpeakCAD from ChatGPT's plugin directory follows OpenAI's availability for plugins. Developer mode, the manual route, is on Plus, Pro, Business, Enterprise and Edu, on chatgpt.com; in a Business, Enterprise or Edu workspace an admin decides whether outside plugins are allowed. Once connected, SpeakCAD is also in the ChatGPT app on iPhone and Android; a plugin added in developer mode may only show on the web, depending on the ChatGPT version.
What it costs
ChatGPT's side is your ChatGPT plan; connecting SpeakCAD is free. SpeakCAD's side is your SpeakCAD account, priced exactly as on the site: 2 credits per AI request (the first design or a change), 10 credits per STL or 3MF download (a paid design re-downloads free after small fixes), and 5 credits more for G-code sliced for your printer (included in Pro and Unlimited). Unlimited also includes the requests and downloads. Typing new dimensions in the card and turning the part around in 3D spend nothing. Ask "how many SpeakCAD credits do I have left?" at any time.
What ChatGPT and SpeakCAD see
ChatGPT sends SpeakCAD the description of the part, each change you ask for, and the printer and settings for a slice; SpeakCAD never sees the rest of the conversation. Files come back as download links, never pasted into the chat, and a file you drop on the card for slicing goes from your browser to the slicer, not through ChatGPT. Connected assistants on your SpeakCAD Plan page disconnects ChatGPT at once. Details: the privacy policy.
Only need G-code for a file you have?
The separate SpeakCAD Slicer plugin (https://speakcad.com/api/mcp/slicer, no sign-in) finds your printer's profile among 380+ printers from 60+ brands, checks your settings and opens the online slicer with them selected: see slice from ChatGPT or Claude.
No plugin? Paste the description
On any ChatGPT plan, the free one included, ask ChatGPT to write the part down with every measurement and paste that text into SpeakCAD: the numbers are used exactly. ChatGPT to STL shows what to keep from the conversation.
Questions
On its own, only roughly: ChatGPT can describe a part, write OpenSCAD code or write a basic STL for a simple shape, but it has no CAD kernel to build, check and export the part it described. With the SpeakCAD plugin it can: ChatGPT hands the description to SpeakCAD's CAD AI, which designs the part, shows it in 3D in the chat and returns a watertight STL or 3MF, or G-code sliced for your printer.
Yes. SpeakCAD works inside ChatGPT and Claude as a plugin (an MCP server): ask the assistant for a part with its measurements and SpeakCAD's own CAD AI designs it, shows it in 3D in the chat and hands over a print-ready STL, 3MF or G-code sliced for your printer. It uses your SpeakCAD account and its credits, exactly as on the site. A second plugin, SpeakCAD Slicer, needs no sign-in and turns an STL or 3MF you already have into G-code for 380+ printers.
On chatgpt.com, open Settings, then Plugins, search for SpeakCAD and press Connect, then sign in with your SpeakCAD account and press Allow. If it does not come up for you, turn on developer mode (Settings, Security and login), press + on the Plugins page and add https://speakcad.com/api/mcp with OAuth. The SpeakCAD in ChatGPT guide shows every click.
Connecting it is free; what it does is paid from your SpeakCAD account at the site's prices: 2 credits per AI request, 10 credits per download, 5 credits more for G-code without Pro or Unlimited. Starter credits is $5 once for 50 credits, no subscription.
Developer mode needs a paid ChatGPT plan (Plus, Pro, Business, Enterprise or Edu); connecting from the plugin directory follows OpenAI's availability for plugins on your plan. Without the plugin, on any plan, ask ChatGPT to write the part down with every measurement and paste it into SpeakCAD: the result is the same file.
Not by itself. With SpeakCAD connected, it looks your printer up among 380+ printers, checks the layer height and material against its OrcaSlicer profile, and the slicer in the card returns the G-code (a .gcode.3mf for Bambu Lab) as a download link with the print time and filament weight. The online slicer gives every account 1 free slice, its first (a free account, no card). After that, a slice uses one slice from a Slicer pack (20 slices for $3, once, never expire) or 5 credits, and slicing is included in Pro and Unlimited. Re-slicing the same file with other settings within 10 minutes is free.
No. SpeakCAD is a plugin built on an MCP server: ChatGPT calls SpeakCAD's tools, and SpeakCAD's own CAD AI and slicer do the work in your account. A GPT is ChatGPT itself with instructions, so it still cannot compile a model or export a file.
Read more
SpeakCAD in ChatGPT, step by stepEvery click, from the plugin directory or developer mode to the first download.SpeakCAD for ClaudeThe same server as a Claude connector, with the part in 3D in the conversation.The SpeakCAD MCP serverThe tools, the addresses and the setup for Claude Code, Cursor and VS Code.Slice from ChatGPT or ClaudeThe SpeakCAD Slicer plugin: an STL you have, G-code for your printer.ChatGPT to STL without the pluginPaste the description ChatGPT wrote; the numbers are used exactly.Enclosure generatorThe most asked-for part: a case for your board, with lid, bosses and cutouts.