nutrient-document-processing-universal（通用营养文件处理）

Nutrient Document Processing (Universal Agent Skill)

Best for Claude Code/Codex/Gemini/Cursor/Windsurf and other non-OpenClaw agents. Process, convert, extract, OCR, 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.

Safety Boundaries

• This skill sends documents to the Nutrient DWS API (api.nutrient.io) for processing. Documents may contain sensitive data — ensure your Nutrient account's data handling policies are acceptable.
• It does NOT access local files beyond those explicitly passed for processing.
• It does NOT store API keys or credentials beyond the current session.
• MCP server mode (npx @nutrient-sdk/dws-mcp-server) downloads the official Nutrient MCP server package from npm at runtime.
• All API calls require an explicit API key — no anonymous access is possible.

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

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