Most LaTeX in the world is written in Overleaf, and for good reason: it is the easiest way for several people to write one paper together. But sooner or later someone asks a different question: how do I compile LaTeX from my own program, from a script, or from an AI agent? Overleaf is an editor for people, and it has no public API for that. This post is about what to use instead, and about when you should not switch at all.
Where Overleaf is the right tool
If you write with co-authors, stay on Overleaf. Shared editing, comments and tracked changes, the history of every version, a large gallery of journal templates and a reviewer who can open the paper in a browser are what Overleaf does best, and an API does not replace any of it. Nothing below argues otherwise.
Where it does not reach
- A program that makes documents. An application that turns data into invoices, reports or certificates needs to send LaTeX and get a PDF back. Overleaf offers no endpoint for that; its Git integration syncs project files and is a paid feature.
- An AI agent on your own machine. Claude Code, Codex and Cursor edit LaTeX very well, but they work on local files, while the paper lives in Overleaf. People have written whole tools to bridge the two, such as overleaf-codex and overleaf-sync-now (which exists because Dropbox sync can hand an agent a copy that is minutes old). The agent still needs a way to see the PDF it just changed.
- Longer compiles on the free plan. Overleaf's plan limits give a free project 10 seconds to compile and a paid one 240. A thesis with many figures can run past the first.
The ways to compile LaTeX without Overleaf
| Good for | The catch | |
|---|---|---|
| Install TeX Live | Full control, offline, no limits | Several gigabytes on every machine, container and CI runner, and agents that run in the cloud cannot install it |
| Overleaf's CLSI | The compile service behind Overleaf, open source, run it yourself | You host, secure and update it |
| Pressa | An HTTP API, an MCP server and a CLI built for programs and agents | A service with plan limits, not an editor |
What Pressa does in that role
Pressa takes LaTeX and returns a PDF over HTTP, with TeX Live 2025 behind it and nothing to install. The first compile needs no key:
curl -X POST https://api.pressa.dev/api/v1/compile \
-H "Content-Type: application/json" \
-d '{"latex": "\\documentclass{article}\\begin{document}Hello\\end{document}"}'- For agents there is an MCP server that Claude, Codex, Cursor and other assistants connect to, and a CLI that compiles a local file with npx.
- When a document does not compile, the answer names the error and the fix, so an agent can correct the source itself instead of handing someone a TeX log.
- For documents a program fills in again and again, saved templates and the render API take JSON and return the PDF.
Using both
The two fit together. Let the agent edit the paper locally and check every change through Pressa, so it sees the real PDF in about a second without a TeX installation; when a section is ready, push it to the Overleaf project, where your co-authors read and comment as before. The paper stays in Overleaf, and the agent stops waiting on sync.
The limits, plainly
| Overleaf Free | Overleaf Standard | Pressa Free | Pressa Pro | |
|---|---|---|---|---|
| Price | $0 | $25 a month | $0 | $29 a month |
| Compile time limit | 10 s | 240 s | 15 s | 60 s |
| Pages per document | No limit | No limit | 5 | 100 |
| API for programs and agents | No | No (Git sync) | Yes | Yes |
| Co-authors in the editor | One | 10 | No editor | No editor |
Overleaf figures from its plans and plan-limits pages, October 2026.
Pressa's free plan is for trying it and for short documents; a long paper needs a paid plan, or Overleaf. Without an account you can compile 3 documents a day, and a free account gives 50 a month. Start with the API, no key needed.