Redact PDFs Using RegEx

Document Engine lets you create redactions on top of text matching a provided regular expression via the createRedactions action(opens in a new tab). This is the most versatile redaction creation strategy.

{
  type: "createRedactions",
  strategy: "regex",
  strategyOptions: {
    regex: "\\d+"
  }
}

See the API Reference(opens in a new tab) for details regarding the regular expression syntax and escaping rules.

Applying Redactions

After redaction annotations are created, they need to be applied to the document to effectively and permanently remove the covered content. You can achieve this by adding the applyRedactions action(opens in a new tab) to the /build instructions(opens in a new tab).

For more information, refer to the API reference to learn about the /api/build endpoint and all the actions you can perform on PDFs with Document Engine.

For an overview of multipart requests, refer to the brief tour of multipart requests blog post.

Creating and Applying Redactions in a File on Disk

Send a multipart request to the /api/build endpoint(opens in a new tab) attached with the input file and the instructions JSON(opens in a new tab):

Terminal window
curl -X POST http://localhost:5000/api/build \
  -H "Authorization: Token token=<API token>" \
  -F file=@/path/to/example-document.pdf \
  -F instructions='{
  "parts": [
    {
      "file": "document",
      "actions": [
        {
          type: "createRedactions",
          strategy: "regex",
          strategyOptions: {
            regex: "\\d+"
          }
        },
        {
          "type": "applyRedactions"
        }
      ]
    }
  ]
}' \
  -o result.pdf

This creates redaction annotations and applies them to the file, removing the content beneath them.

Creating and Applying Redactions in a File from a URL

Send a request to the /api/build endpoint(opens in a new tab) and include a URL pointing to the file you want to redact:

Terminal window
curl -X POST http://localhost:5000/api/build \
  -H "Authorization: Token token=<API token>" \
  -F instructions='{
  "parts": [
    {
      "file": {
        "url": "https://pspdfkit.com/downloads/examples/credit-card-application.pdf"
      },
      "actions": [
        {
          type: "createRedactions",
          strategy: "regex",
          strategyOptions: {
            regex: "\\d+"
          }
        },
        {
          "type": "applyRedactions"
        }
      ]
    }
  ]
}' \
  -o result.pdf

This creates redaction annotations and applies them to the file, removing the content beneath them.