One API.
Every PDF workflow.

Overview

LittlePDF exposes 30 of its 36 tools programmatically through three interfaces: a CLI tool for any AI agent or terminal, an MCP Server for IDE-native integrations, and a REST API for traditional applications. The CLI and REST paths hold your file in memory for the request and keep no copy. MCP is the exception: it stores each output so your client can download it, and removes it automatically after 24 hours.

Authentication

All API and MCP requests require authentication. Generate an API key from your LittlePDF Dashboard. Use the Authorization header with a Bearer token.

curl -X POST https://api.littlepdf.com/v1/merge \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: multipart/form-data" \
  -F "files[]=@doc1.pdf" \
  -F "files[]=@doc2.pdf"

Quickstart

Both plans include CLI and MCP access. Free gives you 500 credits a day, Pro gives you 5,000.

npx @littlepdf/cli auth --key YOUR_API_KEY

littlepdf list
littlepdf merge-pdf --help

littlepdf merge-pdf --files doc1.pdf doc2.pdf -o merged.pdf

CLI Tool

The @littlepdf/cli package gives any AI agent or terminal access to all LittlePDF tools via simple shell commands. Unlike MCP (which injects all tool schemas into context every turn), CLI-based access uses lazy discovery: --list and --help load only what's needed.

Installation

Run directly with npx (no install needed) or install globally:

npx @littlepdf/cli list

Authentication

The CLI resolves your API key in this order (highest priority first):

• --key lpdf_xxx inline flag
• LITTLEPDF_API_KEY environment variable
• ~/.littlepdf/config.json config file

Save your key once with:

littlepdf auth --key YOUR_API_KEY

Tool Discovery

Use list and --help to discover tools without reading docs:

# List all tools with credit costs
littlepdf list

# See parameters for a specific tool
littlepdf compress-pdf --help

# Check your credit balance
littlepdf balance

Usage Examples

littlepdf merge-pdf --files doc1.pdf doc2.pdf -o merged.pdf

AI Agent Setup

The CLI ships with a SKILL.md file that AI agents can read for tool discovery. Point your agent to node_modules/@littlepdf/cli/SKILL.md or include the key commands in your system prompt:

littlepdf list              # See all tools
littlepdf <tool> --help     # See parameters
littlepdf balance           # Check credits

MCP Server

For IDE-native integrations, LittlePDF provides a Streamable HTTP MCP server that enables Claude Desktop, Cursor, Windsurf, and Claude Code to directly access all PDF tools without leaving the editor.

Configuration

Add LittlePDF to your AI assistant's MCP configuration:

{
  "mcpServers": {
    "littlepdf": {
      "url": "https://littlepdf.com/api/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

Available Tools

The MCP server registers 33 tools: 30 that do work on a file, plus 3 for checking credits, listing tools and reading your history. They are grouped below by credit cost.

A tool that produces a file answers with a download link rather than the bytes, because an MCP client is usually a model and a multi-megabyte base64 blob would eat its context. That means the output is written to a private bucket under your account id. The link expires an hour after it is issued. The object behind it is not on a deletion schedule today, so treat MCP output as held by us until you ask us to remove it.

REST API

For traditional integrations, LittlePDF provides simple RESTful endpoints for every tool. All endpoints accept multipart/form-data and return the processed file.

Make a Request

curl -X POST https://api.littlepdf.com/v1/merge \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: multipart/form-data" \
  -F "files[]=@doc1.pdf" \
  -F "files[]=@doc2.pdf" \
  -o merged.pdf

Endpoints

Every tool is available as a POST endpoint at /v1/{tool-slug}:

Error Handling

All API errors return a consistent JSON response with an error code and message:

{
  "error": {
    "code": "rate_limit_exceeded",
    "message": "Daily credit limit reached. Resets at midnight UTC.",
    "status": 429
  }
}

Credits System

API and MCP usage consumes credits based on the operation type. Credits reset daily at midnight UTC. There are no overage charges: once the pool is empty, calls stop until the next reset.

Operation Costs

Plans

LittlePDF offers a simple two-tier pricing model. Both plans include full CLI, MCP, and API access.