@pressa/mcp

@pressa/mcp

MCP (Model Context Protocol) server for Pressa - LaTeX in, publication-quality PDF out. This server lets AI assistants compile documents through a standardized interface.

No API key required to start. Add the server, ask for a PDF, get one. A key raises the limits later.

Setup

Add this to your MCP client configuration (e.g. Claude Desktop, Cursor):

{
  "mcpServers": {
    "pressa": {
      "command": "npx",
      "args": ["-y", "@pressa/mcp"]
    }
  }
}

That is the whole configuration. The server starts in anonymous mode and exposes the compile tool, which works with no credentials: 3 successful compilations per day, and failed attempts do not count against that, so an assistant can iterate on its LaTeX for free.

To unlock the rest, add a key:

{
  "mcpServers": {
    "pressa": {
      "command": "npx",
      "args": ["-y", "@pressa/mcp"],
      "env": {
        "PRESSA_API_KEY": "pressa_your_key_here"
      }
    }
  }
}

Get a free key at pressa.dev. Takes about 30 seconds, no credit card. It raises the limit to 50 compilations per month and registers the template, asset and render tools.

Hosted server (no install)

The same tools are also served over Streamable HTTP at https://api.pressa.dev/mcp, so a client that supports remote MCP servers needs no Node.js and no local process:

claude mcp add --transport http pressa https://api.pressa.dev/mcp

Keyless, it exposes compile and the public template gallery (list_public_templates, get_public_template, render_public_template). Send an Authorization: Bearer <key> header to register the template, asset and render tools as well.

Environment Variables

Variable	Required	Default	Description
PRESSA_API_KEY	No	-	Pressa API key (starts with pressa_). Without it the server runs in anonymous mode and exposes only compile.
PRESSA_API_URL	No	https://api.pressa.dev	API base URL

Anonymous mode

With no PRESSA_API_KEY set, the server starts anyway rather than refusing to run, and registers exactly one tool: compile. Tools that need an account are not registered at all, because a tool that cannot succeed is worse than an absent one.

Anonymous limits: pdflatex only, up to 3 pages, 30 KB of source, no image assets, and PDF links that expire after 1 hour.

Error handling

Compilation failures return a structured diagnosis rather than a raw TeX log: the error class, the offending command, and a concrete suggested fix (often a missing \usepackage). An assistant is expected to apply the fix and retry on its own instead of showing the user a compiler log.

Tools

compile

Compile LaTeX source code into a PDF.

Input:

Parameter	Type	Required	Description
latex	string	Yes	Complete LaTeX source code. Must contain \documentclass, \begin{document}, \input{}, or \include{}. Plain text, markdown, or raw notes are rejected with not_latex_source (422). The AI agent should generate LaTeX itself, not bounce back to the user.
compiler	string	No	"pdflatex" (default), "xelatex", or "lualatex" (Pro and Business plans only)

Each plan has limits on pages per document, LaTeX source size, PDF output size, and compile timeout. If a compile exceeds your plan's page limit, the document does not count against your monthly quota and the MCP response includes the limit and an upgrade URL. Non-LaTeX input is rejected with a structured requirements list and an example_template so the LLM can self-correct without user intervention.

Output (success):

{
  "job_id": "ffc2bd62-3b67-45d6-be14-b529c4b9489f",
  "pdf_url": "https://api.pressa.dev/api/v1/pdfs/ffc2bd62...?sig=xxx&exp=xxx",
  "expires_at": "2026-04-09T20:44:55Z",
  "pages": 1,
  "compilation_time_ms": 359,
  "usage": {
    "plan": "free",
    "compilations_this_month": 9,
    "monthly_limit": 50
  }
}

Output (error): Compilation log and error line number.

usage

Get current API usage statistics.

Input: None.

Output:

{
  "user": {
    "email": "[e-mail]",
    "username": "user",
    "plan": "free"
  },
  "usage": {
    "compilations_this_month": 9,
    "monthly_limit": 50,
    "remaining": 41,
    "resets_at": "2026-04-30T23:59:59Z"
  },
  "api_key": {
    "prefix": "pressa_a",
    "name": "my-key",
    "total_requests": 15,
    "last_used_at": "2026-04-08T20:44:55Z"
  }
}

save_template

Save or update a LaTeX template by name. Paid plans only. Upserts: a second call with the same name overwrites the first.

Parameter	Type	Required	Description
name	string	Yes	Template name (max 100 chars). Unique per user.
latex_content	string	For a new template	Full LaTeX source for the template body. May be omitted when converting the saved source with placeholder_engine: "liquid".
description	string	No	Short human-readable summary (max 500 chars). Shown in list_templates.
instructions	string	No	Agent playbook (prose markdown, max 50000 chars). Describes how to fill the template - defaults, workflow rules, edge cases, conditional logic. Optional but recommended for templates with dynamic parts. See note below.
placeholder_engine	string	No	"liquid": the source contains Liquid placeholders ({{ amount }}) filled by render; on an existing raw LaTeX template this converts it in place (same id, name and instructions). "none": raw LaTeX whose braces only look like placeholders. Omit to keep the template's current kind.

description vs instructions: description is the one-line UI summary ("Standard Toptal monthly invoice"). instructions is the longer playbook your AI agent reads alongside the LaTeX when filling the template ("Ask the user only for total amount; date is today; invoice number format YYYYMMDD-N where N is sequential count for the calendar year; for EU clients add VAT line"). They are different fields.

Raw LaTeX vs placeholder templates: a raw LaTeX template is compiled exactly as saved. A placeholder template is filled with JSON data by render, so the layout never changes. A source containing Liquid placeholders sent without placeholder_engine is refused with liquid_placeholders_in_v1_template, because raw LaTeX would print the braces literally in the PDF. If a placeholder save returns liquid_syntax_error, wrap the literal LaTeX that Liquid misreads (usually a comment right after a brace, \foo{%) in {% raw %}...{% endraw %}.

list_templates

List the user's saved templates. Does not include latex_content or instructions to keep the response small.

Input: None.

Each item in the returned array carries id, name, description, updated_at, latex_size_bytes, and has_instructions (boolean). Use the has_instructions flag to decide whether a follow-up get_template call will return a useful playbook.

get_template

Fetch a single template by ID or name. Returns the full latex_content plus instructions (if any) in one round trip - your agent gets the layout and the playbook together.

Parameter	Type	Required	Description
id_or_name	string	Yes	Numeric ID or URL-safe template name.

delete_template

Delete a template by ID or name.

Parameter	Type	Required	Description
id_or_name	string	Yes	Numeric ID or URL-safe template name.

Development

npm install
npm run build
npm start

License

MIT