letX connector
Use letX inside ChatGPT
Compile LaTeX to PDF, use 1000+ templates, and create letX projects, without leaving ChatGPT.
Listed in ChatGPT’s plugin directory, which Codex shares. Connecting needs a paid letX plan: Pro, Academic Pro, or a seat on a Team.
Pro is $18 a month, Academic Pro $9 a month for verified students, faculty and staff, and a Team seat $20 a month. See the plans
- 1
Open Plugins in ChatGPT
Choose Plugins in the ChatGPT sidebar. Or go straight to letX’s page in the directory while signed in to ChatGPT, and skip the next step.
- 2
Find letX
Type letX into Search plugins and open it. Its line reads Write and compile LaTeX.
- 3
Install it and connect
Press Install plugin, then Connect, which opens the letX sign-in. On a Business, Enterprise or Edu workspace an admin decides which plugins members can install, so if letX is not offered there, ask them.
- 4
Sign in, or make an account
If you are not already signed in to letX, this is where you land. Use Google or GitHub, or fill in the form. Already have an account? Press Sign in at the top. Connecting needs a paid letX plan (Pro, Academic Pro, or a seat on a Team); on a free account the next screen says so and links to the plans.
- 5
Allow access
Last screen. Read what ChatGPT is asking for, then press Allow access. letX never hands over your password, and you can disconnect later from Settings → Connected apps.
- 6
Use it
Start a message with @letX, or simply ask: “compile this LaTeX and give me the PDF”, “find an IEEE paper template and start a project”, or “fix the compile error in my thesis project”. The plugin brings two skills, compile-and-fix and start-from-template, so ChatGPT compiles, reads the error by file and line, fixes it and compiles again.
Adding it by URL instead
The same server also works as a custom MCP server in ChatGPT’s developer mode, for example where a workspace has not made the directory plugin available. Developer mode is not on every ChatGPT plan or workspace. You get the same thirteen tools, without the two skills. These are the clicks.
- 1
Turn on developer mode
Open ChatGPT Settings → Security and login (some layouts put it under Apps or Connectors instead) and switch on Developer mode. That is what lets you add a server by its URL.
1 Security and login. 2 the Developer mode toggle, switched on. - 2
Open Plugins and press add
Choose Plugins in the ChatGPT sidebar, then the + button at the top right of that page.
Plugins, in the sidebar. 
The + button, top right. - 3
Fill in letX and press Create
Name it letX, write a short description, and paste the server URL
https://api.letx.app/mcpunder Connection → Server URL. Set Authentication to OAuth, tick the box confirming you want to continue, then press Create. The icon is optional and there is nothing to fill in under advanced OAuth settings.
1 name. 2 the letX server URL. 3 Authentication, set to OAuth. 4 the confirmation box. 5 Create. - 4
Press Sign in with letX
Creating the plugin does not connect it. ChatGPT shows a card for letX, and the button on it starts the sign-in.
Sign in with letX.
Then sign in and allow access exactly as in steps 4 and 5 above.
What ChatGPT can do with letX connected
- Compile LaTeX → PDF on a real TeX Live farm
- Search 1000+ free LaTeX templates
- Start projects from any template
- Read & edit your project files
- See compile errors and fix them itself
- Hand off to the letX editor anytime
Frequently asked questions
Do I need a paid plan?
On letX, yes. Connecting ChatGPT is part of letX’s paid plans (Pro, Academic Pro, or a seat on a Team). A free account is stopped at the consent screen with a link to the plans. Compiles that ChatGPT runs count against your letX plan like any other.
Is letX in ChatGPT’s plugin directory?
Yes, as letX, at https://chatgpt.com/plugins/plugin_asdk_app_6ad43ec6eaec8191a9b35116ac0c8b64 for a signed-in ChatGPT user. In ChatGPT, open Plugins in the sidebar, search for letX, install it and connect your letX account. OpenAI keeps one directory for ChatGPT and Codex, so Codex lists the same plugin. The directory plugin and a server added by URL in developer mode reach the same server, https://api.letx.app/mcp, with the same thirteen tools.
What can ChatGPT do with my account?
Exactly what you approve on the consent screen: browse templates, read and edit your projects, and compile. It cannot delete projects, manage sharing, or see your password. Disconnect anytime from Settings → Connected apps.
Do I still need developer mode?
No. Developer mode is only for adding letX by its URL instead of from the directory. If you want that route, ChatGPT moves the switch as the app changes: look under Settings then Security and login first, then Apps or Connectors.
Can it insert images or figures?
The connector handles text files (.tex.bib). For figures, open the project in letX. The editor handles uploads, live preview, and collaboration.