API Reference

Complete reference for the FormaTeX REST API. Compile LaTeX documents to PDF with a single HTTP call.

Quick Example

curl -X POST https://api.formatex.io/api/v1/compile \
  -H "X-API-Key: your-api-key" \
  -H "Content-Type: application/json" \
  -d '{"latex": "\\documentclass{article}\\begin{document}Hello!\\end{document}"}' \
  --output document.pdf

Authentication

Two auth methods: JWT tokens for account management, API keys for compilation.

Users

Manage your profile and view usage statistics. All endpoints require JWT.

API Keys

Create and manage API keys for compilation. All endpoints require JWT.

Compilation

Compile LaTeX to PDF. All compilation endpoints require an API Key.

{
  "latex": "\\documentclass{article}\\begin{document}\\includegraphics{logo}\\end{document}",
  "engine": "pdflatex",
  "files": [
    { "path": "logo.png", "data": "<base64-encoded-content>" },
    { "path": "refs.bib", "data": "<base64-encoded-content>" }
  ]
}

Templates

Parameterized LaTeX documents with <<variable>> placeholders. Send data, get PDF — no LaTeX knowledge required for your API consumers.

How it works

1. Browse the template library or create your own
2. Send a compile request with variable values
3. Receive a compiled PDF with all placeholders substituted

Variable schema

Quick example

curl -X POST https://api.formatex.io/api/v1/templates/cover-letter/compile \
  -H "X-API-Key: your-api-key" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -d '{"variables": {"name": "Alice Martin", "company": "Acme Corp"}}' \
  --output cover-letter.pdf

Without the Accept: application/json header, the response is a raw PDF binary.

Public Templates

Curated templates available to all users. No authentication required to list or view. Compilation requires an API key.

User Templates

Create and manage your own parameterized templates. Requires JWT authentication. Available on Pro plan and above.

Webhooks

Register HTTP callbacks to receive real-time notifications on compilation, quota, and plan events. Requires JWT. Failed deliveries are automatically retried up to 5 times with exponential backoff.

Event Payload

{
  "event": "compilation.success",
  "data": {
    "compilationId": "uuid",
    "engine": "pdflatex",
    "durationMs": 1240,
    "inputSizeBytes": 2048,
    "apiKeyPrefix": "a2e67d28...",
    "timestamp": "2026-02-20T14:30:00Z"
  }
}

If a secret is set, the payload is signed with HMAC-SHA256 delivered in the X-FormaTeX-Signature header.

Billing

Subscription management via Polar.sh. Requires JWT authentication.

Plans

View available plans and their limits. Public endpoint.

Plan Comparison

MCP Server

Compile LaTeX directly from AI agents — Claude Desktop, Cursor, Claude Code, n8n, and more — with zero local TeX Live installation. Uses your FormaTeX API key for authentication.

Available Tools

Setup

{
  "mcpServers": {
    "formatex": {
      "url": "https://mcp.formatex.io/mcp",
      "headers": {
        "Authorization": "Bearer fex_your_api_key_here"
      }
    }
  }
}

curl https://mcp.formatex.io/health
# → {"status":"ok","service":"formatex-mcp","version":"1.0.0"}

Troubleshooting

Errors

All errors return a consistent JSON format with an error message and optional context.

{
  "error": "human-readable error message",
  "plan": "free",
  "limit": 100,
  "used": 100
}