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This demo video shows an example of how we used Contractag’s REST API to build a mini SignNow-like app for extracting and validating fields from legal documents.

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Demo Video

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Example Implementation: Mini SignNow App

This example demonstrates integrating Contractag’s API into a document signing workflow. Here’s how we built it:
  1. Basic Frontend: Users can provide the name and email of the recipient, attach a contract PDF, and send it for signing.
  2. Upload Document: Send PDF to POST /fields to extract all detectable fields.
  3. Field Validation: Display extracted fields with confidence scores for review.
  4. Signature Placement: Use bounding boxes to position signature fields automatically.
  5. Document Preparation: Ensure all required fields are present before sending for signatures.
Users can adapt this approach to their preferred e-signature platforms or custom workflows. Note: We can also incorporate a human-in-the-loop step where fields can be verified and adjusted as needed. Warning: The output of geometry dimensions is not supposed to be correct for this example.

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API Endpoints Used

  • POST /fields - Extract all fields from a PDF
  • GET /fields/{document_id} - Retrieve extracted fields by document ID (with optional page parameter)
For full API documentation, see the API Reference.

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Next Steps