Lexi
An in-editor LaTeX agent that reads the project and compile log, edits source, recompiles, and keeps the previous version recoverable.
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Live
Collaborative research infrastructure
LetX
A real-time collaborative LaTeX editor with cloud compilation, Lexi, templates, and project history.
Verified facts
- 4,400+ registered users
- 1,000+ compile-tested templates
- 350+ universities and labs
- Unlimited collaborators on every plan
System brief
What it does.
LetX provides shared LaTeX projects, real-time editing, templates, cloud compilation, version history, Lexi, and an MCP server. It is the primary product of Shahriar Labs.
Hosted MCP server
On Pro, connect Claude, ChatGPT, Claude Code, or another OAuth-capable MCP client to search templates, create projects, edit files, and compile PDFs.
Real-time collaboration
Conflict-free editing through Yjs CRDT sync, cursor presence, shared projects, and version history.
Full TeX Live
Cloud compilation with pdfLaTeX, XeLaTeX, and LuaLaTeX, plus more than 5,000 CTAN packages.
Free, Pro, and Academic Pro pricing
Free includes 40 daily compiles, all templates, and unlimited collaborators. Pro is $18 monthly or $180 yearly. Academic Pro is $9 monthly or $90 yearly for students, faculty, and staff, and requires a current transcript or student or staff ID.
Payments and privacy
Subscriptions are handled by Lemon Squeezy as merchant of record. LetX does not receive full card numbers and private documents are not used to train AI without explicit opt-in consent.
Launch
LetX
Write LaTeX together. The AI runs the build.
Verified September 25, 2026
LetX usage and platform figures.
- 4,400+
- registered users
- 350+
- universities & labs
- 60+
- countries
- 1,000+
- free templates
- 220M+
- Lexi tokens processed
- ~6 s
- typical compile
- 5,000+
- CTAN packages
- Jan 27, 2026
- public launch
Canonical source: letx.app/stats and LetX's production-backed public statistics source. Adoption figures are rounded down and dated so they do not imply false precision.
Lexi
Project editing with compiler feedback.
Lexi reads the open LetX project, including files, bibliography, and the actual compile log. It can edit the source, compile the result, inspect the error, and try again.
Its command surface includes fixing compile errors, building tables and TikZ diagrams, converting screenshots and PDFs into LaTeX, creating Beamer slides, adding citations, formatting, translating, and targeted inline edits. Lexi is a Pro feature with a monthly allowance; the editor, templates, collaboration, and free compilation remain available without it.
Read the full Lexi research page →MCP
Connect an AI client to LetX.
The hosted endpoint at https://api.letx.app/mcp connects through OAuth 2.1. It lets compatible clients search the template library, create projects, list and read project files, update source, and compile LaTeX to PDF.
LetX documents thirteen tools: five read-only (template search and detail, project and file listing, file reading), six that write (create a project from a template or from source, update a file, compile loose LaTeX, compile a project, set the compiler), and conventional search and fetch compatibility for ChatGPT deep research. It is tested with Claude, ChatGPT, and Claude Code. The client never receives the user’s password, write scopes are disclosed on consent, access can be revoked, and prior file versions remain in LetX history.
Read the full MCP research page →Plans & payments
Free, Pro, and Academic Pro.
Free
$0
- 40 compiles per day
- Last 15 versions
- All 1,000+ templates
- Unlimited collaborators
Pro
$18 / month
- $180 per year
- Unlimited compiles
- Lexi monthly allowance
- MCP access for Claude and ChatGPT
- Full version history
- Priority compile queue
- GitHub import/export
Academic Pro
$9 / month
- $90 per year
- Students, faculty, and staff
- Unlimited compiles and a reduced Lexi allowance
- Needs a current transcript or student or staff ID
- Classroom, lab, and department plans are custom
The LetX pricing page listed Academic Pro at $9 per month or $90 per year when checked on September 27, 2026. Self-service checkout is live by card. LetX names Lemon Squeezy as merchant of record for subscription payment processing. Classroom, lab, university, and department plans use custom pricing.
Verify current LetX pricing ↗Official LetX links