Nutrient Document Processing

Process, convert, extract, redact, sign, and manipulate documents using the Nutrient DWS Processor API.

Setup

You need a Nutrient DWS API key. Get one free at https://dashboard.nutrient.io/sign_up/?product=processor.

Option 1: MCP Server (Recommended)

If your agent supports MCP (Model Context Protocol), use the Nutrient DWS MCP Server. It provides all operations as native tools.

Configure your MCP client (e.g., claude_desktop_config.json or .mcp.json):

{
  "mcpServers": {
    "nutrient-dws": {
      "command": "npx",
      "args": ["-y", "@nutrient-sdk/dws-mcp-server"],
      "env": {
        "NUTRIENT_DWS_API_KEY": "YOUR_API_KEY",
        "SANDBOX_PATH": "/path/to/working/directory"
      }
    }
  }
}

Then use the MCP tools directly (e.g., convert_to_pdf, extract_text, redact, etc.).

Option 2: Direct API (curl)

For agents without MCP support, call the API directly:

export NUTRIENT_API_KEY="your_api_key_here"

All requests go to https://api.nutrient.io/build as multipart POST with an instructions JSON field.

Operations

1. Convert Documents

Convert between PDF, DOCX, XLSX, PPTX, HTML, and image formats.

HTML to PDF:

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "index.html=@index.html" \
  -F 'instructions={"parts":[{"html":"index.html"}]}' \
  -o output.pdf

DOCX to PDF:

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "document.docx=@document.docx" \
  -F 'instructions={"parts":[{"file":"document.docx"}]}' \
  -o output.pdf

PDF to DOCX/XLSX/PPTX:

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "document.pdf=@document.pdf" \
  -F 'instructions={"parts":[{"file":"document.pdf"}],"output":{"type":"docx"}}' \
  -o output.docx

Image to PDF:

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "image.jpg=@image.jpg" \
  -F 'instructions={"parts":[{"file":"image.jpg"}]}' \
  -o output.pdf

2. Extract Text and Data

Extract plain text:

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "document.pdf=@document.pdf" \
  -F 'instructions={"parts":[{"file":"document.pdf"}],"output":{"type":"text"}}' \
  -o output.txt

Extract tables (as JSON, CSV, or Excel):

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "document.pdf=@document.pdf" \
  -F 'instructions={"parts":[{"file":"document.pdf"}],"output":{"type":"xlsx"}}' \
  -o tables.xlsx

Extract key-value pairs:

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "document.pdf=@document.pdf" \
  -F 'instructions={"parts":[{"file":"document.pdf"}],"actions":[{"type":"extraction","strategy":"key-values"}]}' \
  -o result.json

3. OCR Scanned Documents

Apply OCR to scanned PDFs or images, producing searchable PDFs with selectable text.

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "scanned.pdf=@scanned.pdf" \
  -F 'instructions={"parts":[{"file":"scanned.pdf"}],"actions":[{"type":"ocr","language":"english"}]}' \
  -o searchable.pdf

Supported languages: english, german, french, spanish, italian, portuguese, dutch, swedish, danish, norwegian, finnish, polish, czech, turkish, japanese, korean, chinese-simplified, chinese-traditional, arabic, hebrew, thai, hindi, russian, and more.

4. Redact Sensitive Information

Pattern-based redaction (preset patterns):

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "document.pdf=@document.pdf" \
  -F 'instructions={"parts":[{"file":"document.pdf"}],"actions":[{"type":"redaction","strategy":"preset","preset":"social-security-number"}]}' \
  -o redacted.pdf

Available presets: social-security-number, credit-card-number, email-address, north-american-phone-number, international-phone-number, date, url, ipv4, ipv6, mac-address, us-zip-code, vin, time.

Regex-based redaction:

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "document.pdf=@document.pdf" \
  -F 'instructions={"parts":[{"file":"document.pdf"}],"actions":[{"type":"redaction","strategy":"regex","regex":"\\b[A-Z]{2}\\d{6}\\b"}]}' \
  -o redacted.pdf

AI-powered PII redaction:

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "document.pdf=@document.pdf" \
  -F 'instructions={"parts":[{"file":"document.pdf"}],"actions":[{"type":"ai_redaction","criteria":"All personally identifiable information"}]}' \
  -o redacted.pdf

The criteria field accepts natural language (e.g., "Names and phone numbers", "Protected health information", "Financial account numbers").

5. Add Watermarks

Text watermark:

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "document.pdf=@document.pdf" \
  -F 'instructions={"parts":[{"file":"document.pdf"}],"actions":[{"type":"watermark","text":"CONFIDENTIAL","fontSize":48,"fontColor":"#FF0000","opacity":0.5,"rotation":45,"width":"50%","height":"50%"}]}' \
  -o watermarked.pdf

Image watermark:

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "document.pdf=@document.pdf" \
  -F "logo.png=@logo.png" \
  -F 'instructions={"parts":[{"file":"document.pdf"}],"actions":[{"type":"watermark","imagePath":"logo.png","width":"30%","height":"30%","opacity":0.3}]}' \
  -o watermarked.pdf

6. Digital Signatures

Sign a PDF with CMS signature:

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "document.pdf=@document.pdf" \
  -F 'instructions={"parts":[{"file":"document.pdf"}],"actions":[{"type":"sign","signatureType":"cms","signerName":"John Doe","reason":"Approval","location":"New York"}]}' \
  -o signed.pdf

Sign with CAdES-B-LT (long-term validation):

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "document.pdf=@document.pdf" \
  -F 'instructions={"parts":[{"file":"document.pdf"}],"actions":[{"type":"sign","signatureType":"cades","cadesLevel":"b-lt","signerName":"Jane Smith"}]}' \
  -o signed.pdf

7. Form Filling (Instant JSON)

Fill PDF form fields using Instant JSON format:

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "form.pdf=@form.pdf" \
  -F 'instructions={"parts":[{"file":"form.pdf"}],"actions":[{"type":"fillForm","fields":[{"name":"firstName","value":"John"},{"name":"lastName","value":"Doe"},{"name":"email","value":"john@example.com"}]}]}' \
  -o filled.pdf

8. Merge and Split PDFs

Merge multiple PDFs:

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "doc1.pdf=@doc1.pdf" \
  -F "doc2.pdf=@doc2.pdf" \
  -F 'instructions={"parts":[{"file":"doc1.pdf"},{"file":"doc2.pdf"}]}' \
  -o merged.pdf

Extract specific pages:

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "document.pdf=@document.pdf" \
  -F 'instructions={"parts":[{"file":"document.pdf","pages":{"start":0,"end":4}}]}' \
  -o pages1-5.pdf

9. Render PDF Pages as Images

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer $NUTRIENT_API_KEY" \
  -F "document.pdf=@document.pdf" \
  -F 'instructions={"parts":[{"file":"document.pdf","pages":{"start":0,"end":0}}],"output":{"type":"png","dpi":300}}' \
  -o page1.png

10. Check Credits

curl -X GET https://api.nutrient.io/credits \
  -H "Authorization: Bearer $NUTRIENT_API_KEY"

Best Practices

1. Use the MCP server when your agent supports it — it handles file I/O, error handling, and sandboxing automatically.
2. Set SANDBOX_PATH to restrict file access to a specific directory.
3. Check credit balance before batch operations to avoid interruptions.
4. Use AI redaction for complex PII detection; use preset/regex redaction for known patterns (faster, cheaper).
5. Chain operations — the API supports multiple actions in a single call (e.g., OCR then redact).

Troubleshooting

Issue	Solution
401 Unauthorized	Check your API key is valid and has credits
413 Payload Too Large	Files must be under 100 MB
Slow AI redaction	AI analysis takes 60–120 seconds; this is normal
OCR quality poor	Try a different language parameter or improve scan quality
Missing text in extraction	Run OCR first on scanned documents

More Information

• Full API reference — Detailed endpoints, parameters, and error codes
• API Playground — Interactive API testing
• API Documentation — Official guides
• MCP Server repo — Source code and issues