📄 PDF MCP Server

A high-performance MCP server for PDF processing, built in Rust.

Give your AI agents powerful PDF capabilities — extract text, search, split, merge, encrypt, and more. All dependencies are Apache 2.0 licensed, keeping your project clean and permissive.

✨ Features

Category	Tools
📖 Reading	extract_text · extract_metadata · extract_outline · extract_annotations · extract_links · extract_form_fields
🔍 Search & Discovery	search · list_pdfs · get_page_info · summarize_structure
🖼️ Media	Image extraction (via extract_text) · convert_page_to_image
✂️ Manipulation	split_pdf · merge_pdfs · compress_pdf · fill_form
🔒 Security	protect_pdf · unprotect_pdf · Password-protected PDF support · Path sandboxing · SSRF protection
📦 Resources	Expose PDFs as MCP Resources for direct client access
⚡ Performance	Batch processing · LRU caching (with byte budget) · Operation chaining via cache keys

🚀 Installation

npm (Recommended)

npm install -g @paradyno/pdf-mcp-server

Pre-built Binaries

Download from GitHub Releases:

Platform	x86_64	ARM64
🐧 Linux	pdf-mcp-server-linux-x64	pdf-mcp-server-linux-arm64
🍎 macOS	pdf-mcp-server-darwin-x64	pdf-mcp-server-darwin-arm64
🪟 Windows	pdf-mcp-server-windows-x64.exe	—

From Source

cargo install --git https://github.com/paradyno/pdf-mcp-server

⚙️ Configuration

Claude Desktop

Add to your claude_desktop_config.json:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "pdf": {
      "command": "npx",
      "args": ["@paradyno/pdf-mcp-server"]
    }
  }
}

Claude Code

claude mcp add pdf -- npx @paradyno/pdf-mcp-server

VS Code

{
  "mcp.servers": {
    "pdf": {
      "command": "npx",
      "args": ["@paradyno/pdf-mcp-server"]
    }
  }
}

🛠️ Tools

Source Types

All tools accept PDF sources in multiple formats:

{ "path": "/documents/file.pdf" }
{ "base64": "JVBERi0xLjQK..." }
{ "url": "https://example.com/document.pdf" }
{ "cache_key": "abc123" }

---

📖 extract_text

Extract text content with LLM-optimized formatting (paragraph detection, multi-column reordering, watermark removal).

{
  "sources": [{ "path": "/documents/report.pdf" }],
  "pages": "1-10",
  "include_metadata": true
}

Parameter	Type	Required	Default	Description
sources	array	Yes	—	PDF sources
pages	string	No	all	Page selection (e.g., "1-5,10,15-20")
include_metadata	boolean	No	true	Include PDF metadata
include_images	boolean	No	false	Include extracted images (base64 PNG)
password	string	No	—	PDF password if encrypted
cache	boolean	No	false	Enable caching

📖 extract_outline

Extract PDF bookmarks / table of contents.

{
  "sources": [{ "path": "/documents/book.pdf" }]
}

Parameter	Type	Required	Default	Description
sources	array	Yes	—	PDF sources
password	string	No	—	PDF password if encrypted
cache	boolean	No	false	Enable caching

Response:

{
  "results": [{
    "source": "/documents/book.pdf",
    "outline": [
      {
        "title": "Chapter 1: Introduction",
        "page": 1,
        "children": [
          { "title": "1.1 Background", "page": 3, "children": [] }
        ]
      }
    ]
  }]
}

📖 extract_metadata

Extract PDF metadata (author, title, dates, etc.) without loading full content.

{
  "sources": [{ "path": "/documents/report.pdf" }]
}

Parameter	Type	Required	Default	Description
sources	array	Yes	—	PDF sources
password	string	No	—	PDF password if encrypted
cache	boolean	No	false	Enable caching

📖 extract_annotations

Extract highlights, comments, underlines, and other annotations.

{
  "sources": [{ "path": "/documents/report.pdf" }],
  "annotation_types": ["highlight", "text"],
  "pages": "1-5"
}

Parameter	Type	Required	Default	Description
sources	array	Yes	—	PDF sources
annotation_types	array	No	all	Filter by types (highlight, underline, text, etc.)
pages	string	No	all	Page selection
password	string	No	—	PDF password if encrypted
cache	boolean	No	false	Enable caching

📖 extract_links

Extract hyperlinks and internal page navigation links.

{
  "sources": [{ "path": "/documents/paper.pdf" }],
  "pages": "1-10"
}

Parameter	Type	Required	Default	Description
sources	array	Yes	—	PDF sources
pages	string	No	all	Page selection
password	string	No	—	PDF password if encrypted
cache	boolean	No	false	Enable caching

Response:

{
  "results": [{
    "source": "/documents/paper.pdf",
    "links": [
      { "page": 1, "url": "https://example.com", "text": "Click here" },
      { "page": 3, "dest_page": 10, "text": "See Chapter 5" }
    ],
    "total_count": 2
  }]
}

📖 extract_form_fields

Read form field names, types, current values, and properties from PDF forms.

{
  "sources": [{ "path": "/documents/form.pdf" }],
  "pages": "1"
}

Parameter	Type	Required	Default	Description
sources	array	Yes	—	PDF sources
pages	string	No	all	Page selection
password	string	No	—	PDF password if encrypted
cache	boolean	No	false	Enable caching

Response:

{
  "results": [{
    "source": "/documents/form.pdf",
    "fields": [
      {
        "page": 1,
        "name": "full_name",
        "field_type": "text",
        "value": "John Doe",
        "is_read_only": false,
        "is_required": true,
        "properties": { "is_multiline": false, "is_password": false }
      },
      {
        "page": 1,
        "name": "agree_terms",
        "field_type": "checkbox",
        "is_checked": true,
        "is_read_only": false,
        "is_required": false,
        "properties": {}
      }
    ],
    "total_fields": 2
  }]
}

🖼️ convert_page_to_image

Render PDF pages as PNG images (base64). Enables Vision LLMs to understand visual layouts, charts, and diagrams.

{
  "sources": [{ "path": "/documents/chart.pdf" }],
  "pages": "1-3",
  "width": 1200
}

Parameter	Type	Required	Default	Description
sources	array	Yes	—	PDF sources
pages	string	No	all	Page selection
width	integer	No	1200	Target width in pixels
height	integer	No	—	Target height in pixels
scale	float	No	—	Scale factor (overrides width/height)
password	string	No	—	PDF password if encrypted
cache	boolean	No	false	Enable caching

Response:

{
  "results": [{
    "source": "/documents/chart.pdf",
    "pages": [
      {
        "page": 1,
        "width": 1200,
        "height": 1553,
        "data_base64": "iVBORw0KGgo...",
        "mime_type": "image/png"
      }
    ]
  }]
}

🔍 search

Full-text search within PDFs with surrounding context.

{
  "sources": [{ "path": "/documents/manual.pdf" }],
  "query": "error handling",
  "context_chars": 100
}

Parameter	Type	Required	Default	Description
sources	array	Yes	—	PDF sources
query	string	Yes	—	Search query
case_sensitive	boolean	No	false	Case-sensitive search
max_results	integer	No	100	Maximum results to return
context_chars	integer	No	50	Characters of context around match
password	string	No	—	PDF password if encrypted
cache	boolean	No	false	Enable caching

🔍 get_page_info

Get page dimensions, word/char counts, token estimates, and file sizes. Useful for planning LLM context usage.

{
  "sources": [{ "path": "/documents/report.pdf" }]
}

Parameter	Type	Required	Default	Description
sources	array	Yes	—	PDF sources
password	string	No	—	PDF password if encrypted
cache	boolean	No	false	Enable caching
skip_file_sizes	boolean	No	false	Skip file size calculation (faster)

Response:

{
  "results": [{
    "source": "/documents/report.pdf",
    "pages": [{
      "page": 1,
      "width": 612.0, "height": 792.0,
      "rotation": 0, "orientation": "portrait",
      "char_count": 2500, "word_count": 450,
      "estimated_token_count": 625,
      "file_size": 102400
    }],
    "total_pages": 10,
    "total_chars": 25000,
    "total_words": 4500,
    "total_estimated_token_count": 6250
  }]
}

Note: Token counts are model-dependent approximations (~4 chars/token for Latin, ~2 tokens/char for CJK). Use as rough guidance only.

🔍 summarize_structure

One-call comprehensive overview of a PDF's structure. Helps LLMs decide how to process a document.

{
  "sources": [{ "path": "/documents/report.pdf" }]
}

Parameter	Type	Required	Default	Description
sources	array	Yes	—	PDF sources
password	string	No	—	PDF password if encrypted
cache	boolean	No	false	Enable caching

Response:

{
  "results": [{
    "source": "/documents/report.pdf",
    "page_count": 25,
    "file_size": 1048576,
    "metadata": { "title": "Annual Report", "author": "Acme Corp" },
    "has_outline": true,
    "outline_items": 12,
    "total_chars": 50000,
    "total_words": 9000,
    "total_estimated_tokens": 12500,
    "pages": [
      { "page": 1, "width": 612.0, "height": 792.0, "char_count": 2000, "word_count": 360, "has_images": true, "has_links": false, "has_annotations": false }
    ],
    "total_images": 5,
    "total_links": 3,
    "total_annotations": 2,
    "has_form": false,
    "form_field_count": 0,
    "form_field_types": {},
    "is_encrypted": false
  }]
}

🔍 list_pdfs

Discover PDF files in a directory with optional filtering.

{
  "directory": "/documents",
  "recursive": true,
  "pattern": "invoice*.pdf"
}

Parameter	Type	Required	Default	Description
directory	string	Yes	—	Directory to search
recursive	boolean	No	false	Search subdirectories
pattern	string	No	—	Filename pattern (e.g., "report*.pdf")

✂️ split_pdf

Extract specific pages from a PDF to create a new PDF.

{
  "source": { "path": "/documents/book.pdf" },
  "pages": "1-10,15,20-z",
  "output_path": "/output/excerpt.pdf"
}

Parameter	Type	Required	Default	Description
source	object	Yes	—	PDF source
pages	string	Yes	—	Page range (see syntax below)
output_path	string	No	—	Save output to file
password	string	No	—	PDF password if encrypted

Page Range Syntax:

Syntax	Description
1-5	Pages 1 through 5
1,3,5	Specific pages
z	Last page
r1	Last page (reverse)
5-z	Page 5 to end
z-1	All pages reversed
1-z:odd	Odd pages only
1-z:even	Even pages only
1-10,x5	Pages 1–10 except page 5

✂️ merge_pdfs

Merge multiple PDFs into a single file.

{
  "sources": [
    { "path": "/documents/chapter1.pdf" },
    { "path": "/documents/chapter2.pdf" }
  ],
  "output_path": "/output/complete-book.pdf"
}

Parameter	Type	Required	Default	Description
sources	array	Yes	—	PDF sources to merge (in order)
output_path	string	No	—	Save output to file

✂️ compress_pdf

Reduce PDF file size using stream optimization, object deduplication, and compression.

{
  "source": { "path": "/documents/large-report.pdf" },
  "compression_level": 9,
  "output_path": "/output/compressed.pdf"
}

Parameter	Type	Required	Default	Description
source	object	Yes	—	PDF source
object_streams	string	No	"generate"	"generate" (best) · "preserve" · "disable"
compression_level	integer	No	9	1–9 (higher = better compression)
output_path	string	No	—	Save output to file
password	string	No	—	PDF password if encrypted

Response:

{
  "results": [{
    "source": "/documents/large-report.pdf",
    "original_size": 5242880,
    "compressed_size": 2097152,
    "compression_ratio": 0.4,
    "bytes_saved": 3145728
  }]
}

✂️ fill_form

Write values into existing PDF form fields and produce a new PDF.

{
  "source": { "path": "/documents/form.pdf" },
  "field_values": [
    { "name": "full_name", "value": "Jane Smith" },
    { "name": "agree_terms", "checked": true }
  ],
  "output_path": "/output/filled-form.pdf"
}

Parameter	Type	Required	Default	Description
source	object	Yes	—	PDF source
field_values	array	Yes	—	Fields to fill (see below)
output_path	string	No	—	Save output to file
password	string	No	—	PDF password if encrypted

Field value format:

Field	Type	Description
name	string	Field name (use extract_form_fields to discover names)
value	string	Text value (for text fields)
checked	boolean	Checked state (for checkbox/radio fields)

Supported field types: Text fields, checkboxes, radio buttons. ComboBox/ListBox selection is read-only.

🔒 protect_pdf

Add password protection using 256-bit AES encryption.

{
  "source": { "path": "/documents/confidential.pdf" },
  "user_password": "secret123",
  "allow_print": "none",
  "allow_copy": false
}

Parameter	Type	Required	Default	Description
source	object	Yes	—	PDF source
user_password	string	Yes	—	Password to open the PDF
owner_password	string	No	user_password	Password to change permissions
allow_print	string	No	"full"	"full" · "low" · "none"
allow_copy	boolean	No	true	Allow copying text/images
allow_modify	boolean	No	true	Allow modifying the document
output_path	string	No	—	Save output to file
password	string	No	—	Password for source PDF if encrypted

🔓 unprotect_pdf

Remove password protection from an encrypted PDF.

{
  "source": { "path": "/documents/protected.pdf" },
  "password": "secret123",
  "output_path": "/output/unprotected.pdf"
}

Parameter	Type	Required	Default	Description
source	object	Yes	—	PDF source
password	string	Yes	—	Password for the encrypted PDF
output_path	string	No	—	Save output to file

📦 MCP Resources

Expose PDFs from configured directories as MCP Resources for direct client discovery and reading.

Enabling Resources

# Command line
pdf-mcp-server --resource-dir /documents --resource-dir /data/pdfs

# Short form
pdf-mcp-server -r /documents -r /data/pdfs

# Environment variable (path-separated: colon on Unix, semicolon on Windows)
PDF_RESOURCE_DIRS=/documents:/data/pdfs pdf-mcp-server

Claude Desktop with resources:

{
  "mcpServers": {
    "pdf": {
      "command": "npx",
      "args": ["@paradyno/pdf-mcp-server", "--resource-dir", "/documents"],
      "env": {
        "PDF_RESOURCE_DIRS": "/data/pdfs:/shared/documents"
      }
    }
  }
}

Both methods can be combined — command line arguments are added to environment variable paths.

Resource URIs

PDFs are exposed with file:// URIs:

file:///documents/report.pdf
file:///documents/2024/invoice.pdf

Operations

• resources/list — Returns all PDFs with URI, name, MIME type, size, and description
• resources/read — Returns extracted text content, formatted for LLM consumption

Resources vs Tools vs Caching

Feature	Purpose	Use Case
Resources	Passive file discovery	Browse and preview available PDFs
Tools	Active PDF processing	Extract, search, manipulate PDFs
CacheRef	Tool chaining	Pass output between operations

🔒 Security

Path Sandboxing

When --resource-dir is specified, all file operations (reads and writes) are sandboxed to the configured directories. Path traversal attempts (e.g., ../../etc/passwd) are blocked via canonicalize().

Without --resource-dir, all paths are allowed (backward compatible).

SSRF Protection

URL sources are checked for SSRF by default. URLs that resolve to private or reserved IP addresses are blocked:

• Loopback (127.0.0.0/8, ::1)
• Private (10/8, 172.16/12, 192.168/16, fc00::/7)
• Link-local (169.254/16, fe80::/10) — blocks cloud metadata endpoints
• CGNAT (100.64/10)
• Broadcast, unspecified

Use --allow-private-urls or PDF_ALLOW_PRIVATE_URLS=1 to disable this check (e.g., for local development).

Resource Limits

Limit	Default	CLI Flag	Env Var
URL download size	100 MB	--max-download-size	PDF_MAX_DOWNLOAD_BYTES
Cache total bytes	512 MB	--cache-max-bytes	PDF_CACHE_MAX_BYTES
Cache entries	100	--cache-max-entries	PDF_CACHE_MAX_ENTRIES
Image scale factor	10.0	--max-image-scale	PDF_MAX_IMAGE_SCALE
Image pixel area	100M	--max-image-pixels	PDF_MAX_IMAGE_PIXELS

🔗 Caching

When cache: true is specified, the server returns a cache_key for use in subsequent requests:

// Step 1: Extract with caching
{ "sources": [{ "path": "/documents/large.pdf" }], "cache": true }

// Step 2: Use cache_key from response
{ "sources": [{ "cache_key": "a1b2c3d4" }], "pages": "50-60" }

🏗️ Architecture

block-beta
  columns 1
  block:server["MCP Server (rmcp)"]
    columns 3
    extract_text search split_pdf
  end
  block:common["Common Layer"]
    columns 3
    Cache["Cache Manager"] Source["Source Resolver"] Batch["Batch Executor"]
  end
  block:pdf["PDF Processing"]
    columns 2
    PDFium["pdfium-render\n(reading)"] qpdf["qpdf FFI\n(manipulation)"]
  end

  server --> common --> pdf

⚡ Performance

Benchmarked with a 14-page technical paper (tracemonkey.pdf, ~1 MB) on Docker (Apple Silicon):

Operation	Time	What it means
Extract text (14 pages)	170 ms	Process ~80 documents per minute
Metadata only	0.26 ms	~4,000 documents per second
Search	0.01 ms	Instant results on extracted text
100 files batch	4.8 s	~21 documents per second

Key takeaways

• Fast enough for interactive use — Text extraction completes in under 200ms
• Metadata is nearly instant — Use extract_metadata or summarize_structure to quickly assess documents before full processing
• Search is blazing fast — Once text is extracted, searching is essentially free
• Batch processing scales linearly — No significant overhead when processing many files

Run benchmarks yourself:

docker compose --profile dev run --rm bench

🧑‍💻 Development

# Build
docker compose --profile dev run --rm dev cargo build

# Run tests
docker compose --profile dev run --rm test

# Run tests with coverage
docker compose --profile dev run --rm coverage

# Format code
docker compose --profile dev run --rm dev cargo fmt --all

# Lint
docker compose --profile dev run --rm clippy

# Performance benchmarks
docker compose --profile dev run --rm bench

# Build production image (~120MB)
docker compose --profile prod build production

# Clean up
docker compose --profile dev down --rmi local

Requires PDFium installed locally. Download from pdfium-binaries and set PDFIUM_PATH.

cargo build --release
cargo test
cargo bench
cargo llvm-cov --html

src/
├── main.rs              # Entry point, CLI args
├── lib.rs               # Library root
├── server.rs            # MCP server & tool handlers
├── error.rs             # Error types
├── pdf/
│   ├── reader.rs        # PDFium wrapper (text, metadata, outline)
│   ├── annotations.rs   # Annotation extraction
│   ├── images.rs        # Image extraction
│   └── qpdf.rs          # qpdf FFI (split, merge, encrypt)
└── source/
    ├── resolver.rs      # Path/URL/Base64 resolution
    └── cache.rs         # LRU caching layer

🗺️ Roadmap

Phase 1: Core Reading ✅

extract_text · extract_outline · search · extract_metadata · extract_annotations · Image extraction · Batch processing · Caching

Phase 2: PDF Manipulation ✅

split_pdf · merge_pdfs · protect_pdf · unprotect_pdf · compress_pdf · extract_links · get_page_info

Phase 2.5: LLM-Optimized Text ✅

Dynamic thresholds · Paragraph detection · Multi-column layout · Watermark removal

Phase 2.6: Discovery & Resources ✅

list_pdfs · MCP Resources · Resource directory configuration

Phase 2.7: Vision & Forms ✅

convert_page_to_image · extract_form_fields · fill_form · summarize_structure

Phase 3: Advanced Features (Planned)

• rotate_pages — Rotate specific pages
• extract_tables — Structured table extraction
• add_watermark — Text/image watermarks
• linearize_pdf — Web optimization
• OCR support · PDF/A validation · Digital signature verification

• Large file upload — MCP lacks a standard API for uploading large files (>20MB). Discussed in #1197, #1220, #1659.
• Chunked file transfer — No standard mechanism exists yet.

Current workarounds: shared filesystem (path), object storage with pre-signed URLs (url), or base64 encoding.

These provide limited value for LLM use cases:

• Hyphenation merging — LLMs understand hyphenated words
• Fixed-pitch mode — Limited use cases
• Bounding box output — LLMs don't need coordinates
• Invisible text removal — Not supported by pdfium-render API

📄 License

Apache License 2.0

🙏 Acknowledgments

• PDFium — PDF rendering engine (Apache 2.0)
• pdfium-render — Rust PDFium bindings (Apache 2.0)
• qpdf — PDF transformation library, vendored via FFI (Apache 2.0)
• rmcp — Rust MCP SDK