Connect SimplyPrint to Gemini CLI
Connect SimplyPrint to Gemini CLI
SimplyPrint has an official MCP server, which means you can plug it into Google's Gemini CLI and just tell Gemini what to do with your printers, queue, files and filament. This guide walks through installing the SimplyPrint extension for Gemini CLI and signing in for the first time.
What you can do once connected
Once Gemini CLI has the SimplyPrint extension, you can ask things like:
- "What's printing right now across all my printers?"
- "Pause every printer - I need to swap filament."
- "Queue five copies of benchy.gcode on the Bambu."
- "Show me what went wrong with the last three failed prints."
- "Which spools have less than 100 grams left?"
Gemini picks the right SimplyPrint action, asks you to confirm anything destructive, and reports back in plain English.
Can I use this in Gemini web (gemini.google.com) instead?
Not yet. As of early 2026, the Gemini web app at gemini.google.com only lets you connect to Google's own tools (Workspace, Maps, YouTube, and Gems). There's no screen for plugging in an outside service like SimplyPrint. The Gemini CLI is the only place in consumer Gemini where you can connect SimplyPrint today.
Google does let you connect outside tools in a few other products, but those are for developers or larger businesses:
- Gemini Enterprise (for businesses): supports custom connectors, but you need to contact your Google account team to be given access.
- Android Studio and Firebase Studio: let developers connect SimplyPrint while they're building software.
- Gemini API (via Google's Python or JavaScript libraries): lets developers use SimplyPrint from code.
If Google opens gemini.google.com to custom connectors in the future, you'll be able to connect SimplyPrint there too - the same way you already can in Claude or any other MCP-aware assistant.
Prerequisites
You need two things installed before you start.
1. Node.js
Gemini CLI runs on Node.js. If you don't already have it, download it from nodejs.org and install with the defaults.
2. Gemini CLI
From any terminal, run:
npm install -g @google/gemini-cli
Verify the install by running gemini --version. You should see a version number print out.
gemini on its own and sign in with your Google account. You only need to do this once. See Google's Gemini CLI quickstart if you get stuck.Install the SimplyPrint extension
With Gemini CLI installed, run:
gemini extensions install https://github.com/SimplyPrint/simplyprint-gemini-extension
When prompted, press Y to continue. The extension is tiny - it's just a pointer at the SimplyPrint MCP server - so the install takes a second or two.
To confirm it installed, you can check the extensions folder at ~/.gemini/extensions/simplyprint/ for a gemini-extension.json file.
First time connecting
Launch Gemini CLI with gemini and ask it something printer-related, like:
What's printing right now?
The first time Gemini needs to call a SimplyPrint tool, a browser window opens so you can sign in to SimplyPrint - the same kind of "Sign in with ..." screen you've seen on other sites. Log in (if you aren't already) and you land on the SimplyPrint permissions screen showing what Gemini is asking for - view printers, control printers, manage queue, and so on. Tick the ones you're happy with and click Authorize.
The browser window closes, Gemini completes its answer using live data from your SimplyPrint account, and your approval is remembered. You won't see the sign-in screen again unless you revoke access.
Permissions Gemini asks for
When you authorize SimplyPrint from Gemini, you get a checklist of permissions. Approve only what you want.
Permission | What it lets Gemini do |
|---|---|
View your printers' details | See names, status, current print, bed temperature |
Operate your printers | Pause, resume, cancel, home, send G-code |
View your print queue | List queue items, view details, see pending approvals |
Manage your print queue | Add items, reorder, edit, delete, approve, deny |
View your files and folders | List files, search by name, estimate print cost |
Manage your files and folders | Move, rename, delete, create folders |
View filament spools | See remaining weight, assignments, drying status |
Manage filament spools | Adjust weight, assign to printers, mark dried |
View your print history | See past jobs, success/failure, filament used |
View your print statistics | Success rate, filament totals, cost summaries |
Managing the extension
A few useful commands:
Command | What it does |
|---|---|
| Show all installed extensions |
| Update to the latest SimplyPrint extension version |
| Temporarily disable without uninstalling |
| Re-enable after disabling |
| Remove the extension completely |
Updates are pushed whenever we ship new SimplyPrint features. You don't need to re-authorize after updating; your scopes are tied to your account, not to any specific version.
Revoking access
To disconnect Gemini CLI from SimplyPrint, go to Account settings > Connected apps in SimplyPrint and click Revoke next to the Gemini entry. The connection stops working immediately. If you want to use Gemini with SimplyPrint again afterwards, you just sign in once more the next time Gemini tries to use a SimplyPrint tool.
gemini extensions uninstall simplyprint removes Gemini's local copy but does not disconnect Gemini from your SimplyPrint account.Troubleshooting
Install fails with "install source not found".
Use the full git URL: gemini extensions install https://github.com/SimplyPrint/simplyprint-gemini-extension. The shorthand SimplyPrint/simplyprint-gemini-extension form isn't recognized by Gemini CLI.
Browser window doesn't open when first connecting.
Make sure you're running gemini interactively in a normal terminal, not piped into another command. Gemini CLI needs to launch your default browser so you can sign in to SimplyPrint.
Gemini says it can't perform an action.
Most likely the permission wasn't granted. Revoke access in Account settings > Connected apps, trigger a SimplyPrint action in Gemini again, and tick the missing permission on the sign-in screen.
Gemini doesn't offer SimplyPrint as a tool.
Run gemini extensions list to confirm simplyprint is listed and enabled. If it's missing or disabled, re-install or enable it with the commands above.
I see Assertion failed: !(handle->flags & UV_HANDLE_CLOSING) on Windows.
This is a known cosmetic Node.js warning on Windows that sometimes appears after a Gemini CLI command completes. The command itself still worked - you can ignore it.
Related articles
- Connect SimplyPrint to any AI assistant via MCP
- Connect SimplyPrint to Claude (claude.ai and Claude Code)
- SimplyPrint API documentation
- The print queue
Updated on: 22/04/2026
Thank you!