--- title: "How to use SpeakCAD in Claude: design a printable part in the conversation" description: "Connect SpeakCAD to Claude: Claude hands your part to SpeakCAD's CAD AI, shows it in 3D in the conversation, and gets you the STL, 3MF or G-code." canonical: https://speakcad.com/guides/speakcad-in-claude published: 2026-09-30 updated: 2026-10-01 publisher: SpeakCAD --- # How to use SpeakCAD in Claude: design a printable part in the conversation > Connect SpeakCAD to Claude: Claude hands your part to SpeakCAD's CAD AI, shows it in 3D in the conversation, and gets you the STL, 3MF or G-code. Claude is good at working out what a part needs: it asks what the part holds, how it mounts and which printer you have, then writes it down with every measurement. The SpeakCAD connector takes it from there. SpeakCAD's own CAD AI designs the part in your SpeakCAD account, Claude shows it in 3D in the conversation with its dimensions to adjust, and you download the STL, the 3MF or G-code sliced for your printer without leaving the chat. ## Steps 1. **Have a SpeakCAD account.** Sign up on speakcad.com (no card asked). Designing, changing and downloading parts spend credits exactly as on the site, so add Starter credits ($5, once) or a plan before the first part. 2. **Add the SpeakCAD connector.** On claude.ai or in Claude Desktop, open Customize, then Connectors. Search the directory for SpeakCAD; if only SpeakCAD Slicer comes up, press +, choose Add custom connector, name it SpeakCAD, paste https://speakcad.com/api/mcp and press Add. There is no client ID or secret to fill in. 3. **Connect, sign in and press Allow.** Press Connect. Claude opens SpeakCAD's sign-in page: sign in the way you usually do, check that the next page names Claude, and press Allow. 4. **Turn it on in a chat.** In a new chat, open the + menu at the bottom left, then Connectors, and check that SpeakCAD is on. Then describe the part with its measurements. 5. **Watch it being designed.** The SpeakCAD card appears in the conversation while the part is designed and shows it in 3D one to two minutes later, with its size and its named dimensions. 6. **Adjust it.** Type new values and press Apply the dimensions (free, a new version), or ask for a change in words, in the card or in the chat (2 credits per AI request, included in Unlimited). 7. **Download the file or the G-code.** Press STL or 3MF for a download link valid 24 hours (10 credits), or say which printer you have and press the G-code button (5 more for the slice, included in Pro and Unlimited). ## What the connector does in Claude Claude can write a part down, or write OpenSCAD code for it, but the file still has to be built, checked and sliced somewhere else. With the SpeakCAD connector, Claude hands the description to SpeakCAD, whose own CAD AI builds a dimensioned model with the FDM design rules applied (walls a nozzle can print, clearance on the fits, a flat base on the bed) and exports a watertight file. It is the same AI and the same rules as in the SpeakCAD editor, and the part is saved in your SpeakCAD models like any other. Claude shows interactive tools right in the conversation, and SpeakCAD uses that: the part appears in a card, in 3D, while it is being designed and after. With the connector, Claude can: - **Design a part** from a description with its measurements, in about one to two minutes. - **Change it** in words, one change at a time, each change a new version; earlier versions 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 among 380+ printers. - **Find a ready-made part** in the SpeakCAD library and the maker marketplace, and show it in 3D. - **Check your balance** and what things cost, so it quotes the right price. ## SpeakCAD or SpeakCAD Slicer? Claude's connectors directory also lists [SpeakCAD Slicer](https://claude.ai/directory/connectors/speakcad). The two are different connectors: - **SpeakCAD**, the one this guide is about, signs in with your SpeakCAD account. It designs and changes parts with SpeakCAD's AI, and slices them or your own files, paid by your account. Server address: `https://speakcad.com/api/mcp` - **SpeakCAD Slicer** needs no sign-in. It slices an STL or 3MF you already have: 3 free slices a day in Claude and ChatGPT without an account, then a free SpeakCAD account to keep slicing. It does not design or change parts. Server address: `https://speakcad.com/api/mcp/slicer` If you only have a file and want G-code, SpeakCAD Slicer is enough: see [slice from ChatGPT or Claude](/guides/slice-from-chatgpt-or-claude). If you want a part designed or changed, add SpeakCAD, which slices too. Both can be on at the same time. ## Before you start - **A SpeakCAD account.** Sign up on speakcad.com; it asks for no card. Designing, changing and downloading parts spend credits exactly as on the site, so add Starter credits ($5, once) or a plan before the first part. You can also create the account from the sign-in window Claude opens. - **Any Claude plan.** Custom connectors work on every Claude plan; the free plan allows one custom connector. On Team and Enterprise, an Owner usually adds a custom connector for the organisation first, and each member then connects their own SpeakCAD account. ## Add the connector Quickest: open [SpeakCAD in Claude's directory](https://claude.ai/directory/speakcad-design), press **Connect** and sign in. Or, on claude.ai in a browser or in the Claude Desktop app: 1. Open **Customize**, then **Connectors**. 2. Search the directory for **SpeakCAD**. If the **SpeakCAD** connector is there (developer SpeakCAD, website speakcad.com), open it and press **Connect**. If only **SpeakCAD Slicer** comes up, carry on with step 3. 3. Press **+**, then **Add custom connector**. 4. Name: `SpeakCAD`. Remote MCP server URL: `https://speakcad.com/api/mcp` 5. Leave the advanced settings (OAuth client ID and secret) empty: SpeakCAD registers Claude by itself. Press **Add**. 6. Press **Connect** on the new connector and sign in. Quicker: [this link](https://claude.ai/customize/connectors?modal=add-custom-connector&connectorName=SpeakCAD&connectorUrl=https%3A%2F%2Fspeakcad.com%2Fapi%2Fmcp) opens **Add custom connector** with the name and the address already filled in. Check that the address is `https://speakcad.com/api/mcp`, press **Add**, then **Connect**. Claude Code and other MCP clients take the same address with the Streamable HTTP transport. In Claude Code: `claude mcp add --transport http speakcad https://speakcad.com/api/mcp`, then `/mcp` in a session to sign in. ## Sign in and allow Claude Claude opens a SpeakCAD window. Sign in the way you usually do (e-mail and password, Google, or a sign-in link by e-mail), or create the account there. The next page names the assistant asking for access, Claude, and the address it will send you back to. Press **Allow** if you started the connection yourself. From then on Claude can design, change, download and slice parts in your SpeakCAD account, paid with its credits, the same way you would on the site. It never sees your password. ## Your first part Start a new chat, open the **+** menu at the bottom left, then **Connectors**, and check that SpeakCAD is on. Then say what you need, with the measurements: > Design a wall mount for my Wi-Fi router with SpeakCAD. The router is 180 x 120 x 35 mm, the cables come out of the back, and the mount hangs on two screws 100 mm apart. If you do not have every number yet, let Claude ask first: "I need a wall mount for my router. Ask me what you need to know, then design it with SpeakCAD." The questions it asks (the router's size, where the cables go, how it hangs) are what makes the first version right. Good requests share three things: measurements in millimetres, what the part fits or holds, and how it attaches. [How to describe a part](/guides/prompting-for-cad) has templates for brackets, enclosures, knobs and stands. Claude may ask for permission the first time it uses one of SpeakCAD's tools. Allowing it always for SpeakCAD saves the clicks; only the tools that design, change, download or slice spend credits. ## In the SpeakCAD card While SpeakCAD designs the part, the card shows "SpeakCAD is designing your part…". One to two minutes later the part appears in 3D, with its size and its version number. Around it: - **The part's named dimensions** (wall thickness, width, hole diameter…) as number fields. Type new values and press **Apply the dimensions**: no AI and no credits, saved as a new version. - **A change in words**: type "walls 3 mm" or "a 5 mm hole in the lid" and press **Change it**. SpeakCAD's AI makes the change (2 credits, included in Unlimited) and the card shows the new version. - **STL** and **3MF**: a download link, valid 24 hours. - **G-code for** your printer, with **Adjust the printer or settings** to choose the printer, the nozzle, the print profile, the material, infill, walls, supports, adhesion and speed. - **Open in SpeakCAD editor**: the same part in the full editor. Claude is told what happens in the card, so the conversation carries on: "the phone slot is 2 mm too narrow" works in the chat as well as in the card. Where a Claude app shows no card, Claude still gets the part's size, its dimensions and the links, and gives them to you in its reply. ## Changes that work One change per message works better than five: SpeakCAD changes what you asked for and keeps the rest. Give the amount ("2 mm wider", "walls 3 mm") rather than an adjective ("bigger", "sturdier"). When the number you want to change is already in the card, typing it is quicker and free. For changes where you need to point at something (this face, that hole), open the part in the editor: you click the face 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 printer. ## G-code for your printer Say which printer you have and how you want to print: "slice it for my Bambu Lab A1 in PETG, 0.2 mm layers, 30% infill". Claude looks the printer up among 380+ printers from 60+ brands and checks your settings against its OrcaSlicer profile: a layer height the profile does not have is refused, with the ones it has. The card then opens the slicer on the part with everything selected. Press the G-code button and the file comes back as a download link, a .gcode file or a sliced .gcode.3mf for Bambu Lab printers, with the print time, the filament in grams and the layer count. G-code counts as a download, plus 5 credits for the slice (included in Pro and Unlimited). Tell Claude your printer once. Put it in your profile preferences or in a Project's instructions ("My printer is a Bambu Lab A1 with a 0.4 mm nozzle; I print PLA and PETG"), and every slice starts from it. ## A file you already have The card slices your own STL or 3MF too. Ask "slice my STL for my Prusa MK4S in PLA" and drop the file on the card when it opens. It goes from your browser straight to the slicer service and is deleted when the job ends; Claude never receives it and only learns the print time, the filament weight and the download link. Slicing your own file follows the online slicer's price: 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. ## On your phone and the desktop app Connectors belong to your Claude account. Add SpeakCAD once on claude.ai or in Claude Desktop, and it is available in the Claude app for iPhone and Android too, turned on the same way from the **+** menu. Whether the 3D card shows in the phone app depends on the app version; when it does not, Claude gives you the links. Every part designed from Claude is also in your SpeakCAD models, and [the SpeakCAD editor runs in Safari and Chrome on a phone](/mobile), with the same 3D view, dimensions and downloads. ## What it costs Exactly what it costs on the site, from the same balance: 2 credits per AI request (the first design or a change), 10 credits per download (a paid design re-downloads free after small fixes), and 5 more for G-code (included in Pro and Unlimited). Unlimited also includes the requests and downloads. Typing new dimensions, turning the part around in 3D and asking Claude questions spend no credits. Adding the connector is free on every Claude plan. Ask "how many SpeakCAD credits do I have left?" at any time. ## What Claude and SpeakCAD see - Claude sends SpeakCAD the description of the part, each change you ask for, and the printer and settings for a slice. SpeakCAD does not see the rest of the conversation. - SpeakCAD sends back the part's status, size, dimensions, version and links. Files come as download links, never pasted into the chat. - Files you drop on the card go from your browser to SpeakCAD's slicer, never through Claude. - The [privacy policy](/privacy) has a section on assistant connectors. To disconnect, open the **Plan** page of your SpeakCAD account: **Connected assistants** lists Claude with a **Disconnect** button that cuts it off at once. You can also disconnect or remove SpeakCAD in Claude, under **Customize**, **Connectors**. ## When something goes wrong - **Claude answers without calling SpeakCAD.** Check in the **+** menu, **Connectors**, that SpeakCAD is on for this chat, then say "use SpeakCAD to design it". - **Claude will not add the custom connector.** The free plan allows one custom connector: remove the other one, or move to a paid Claude plan. On Team and Enterprise, ask an Owner to add it. - **The sign-in window closed and nothing connected.** Allow pop-ups for claude.ai and press Connect again. - **Not enough credits.** The card's **Add credits** button opens your SpeakCAD Plan page. - **The design takes more than two minutes.** It finishes anyway and lands in your SpeakCAD models. Ask Claude "is my part ready?", or open it in the editor. ## No connector? Paste the description The connector is a convenience. Ask Claude to write the part down with every measurement, copy the text and paste it into SpeakCAD: the numbers are used exactly. The [ChatGPT to STL page](/chatgpt-to-stl) shows what to keep from the conversation, and it works the same with Claude. Using ChatGPT instead? [SpeakCAD in ChatGPT](/guides/speakcad-in-chatgpt) covers the same connector there. ## About SpeakCAD SpeakCAD is the mobile-first AI 3D editor for 3D printing: describe a part in plain English on your phone or computer and get an instant, print-ready STL or 3MF, or G-code already sliced for your printer. 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. - Live demo, no account: https://speakcad.com/demo - In ChatGPT, Claude and other MCP clients: https://speakcad.com/chatgpt-plugin, https://speakcad.com/claude-connector, https://speakcad.com/mcp-server - Pricing: https://speakcad.com/pricing - FAQ: https://speakcad.com/faq - Site index for AI assistants: https://speakcad.com/llms.txt