Alfresco Transformer: Docling-based PDF/Office/HTML/Image ➜ Markdown & JSON + md2pdf-based Markdown ➜ PDF

This project provides an Alfresco Content Services (ACS) transformer that converts a wide variety of document types into Markdown and JSON formats using Docling and md2pdf, lightweight document conversion libraries licensed under the MIT License.

The transformer runs inside a Docker container and can be integrated into Alfresco as a local transformer.

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🚀 Docling Supported Transformations

Docling supports the following source formats, converted into:

• text/markdown
• text/x-markdown
• application/json

📄 Document Types

• PDF (application/pdf)
• Word (.docx) (application/vnd.openxmlformats-officedocument.wordprocessingml.document)
• Excel (.xlsx) (application/vnd.openxmlformats-officedocument.spreadsheetml.sheet)
• PowerPoint (.pptx) (application/vnd.openxmlformats-officedocument.presentationml.presentation)
• Markdown (text/markdown)
• AsciiDoc (text/asciidoc)
• HTML (text/html, application/xhtml+xml)
• CSV (text/csv)
• Docling JSON (application/vnd.docling+json)

🖼️ Image Types (Markdown only)

• PNG (image/png)
• JPEG (image/jpeg)
• TIFF (image/tiff)
• BMP (image/bmp)

🧾 Specialized Formats

• JATS XML (application/vnd.jats+xml)
• USPTO XML (application/vnd.uspto+xml)

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🚀 md2pdf Supported Transformations

text/markdown => application/pdf

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🛠️ Getting Started

🧱 Build and run the Docker Image

To create the transformer Docker image, run:

./run.sh build

This uses alfresco-base-java and installs Python 3 and the docling package via pip.

To run the image :

./run.sh start

• Port 8090 is for transformations
• Port 8099 is for debugging

Example of request to transform a PDF file to Markdown:

curl --location --request POST 'http://localhost:8090/transform' \
--form 'file=@"/path/to/sample.pdf"' \
--form 'sourceMimetype="application/pdf"' \
--form 'targetMimetype="text/markdown"'

🔗 Register with Alfresco

You can declare the Docker service as follow in a docker-compose.yml file:

  becpg-transform-markdown:
    image: becpg-transform-markdown:1.0.0
    ports:
      - "8090:8090"
    environment:
      - SERVER_PORT=8090
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:8090/live"]
      interval: 30s
      timeout: 10s
      retries: 5

Add the following JVM property to your Alfresco instance:

-DlocalTransform.becpg-transform-markdown.url=http://localhost:8090/

This allows Alfresco to discover and use the transformer.

Licenses

• This project uses Docling and md2pdf, licensed under the MIT License.

• Base image from Alfresco Docker Base Java

🙌 Acknowledgments

• Docling and md2pdf — for doing the heavy lifting
• Alfresco — for the open content services platform
• Community contributors and open-source maintainers

Feel free to fork, contribute, or open issues. Happy transforming!