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Credits

Credits

Built on open-source releases from Filed and Crimson Tree Software, part of the Open Tax Technology Alliance. Drivkraft Tax is an independent practice project. It isn't affiliated with or endorsed by either of them.

Read the case study

  • OpenTax

    Filed Inc.

    Form 1040 calculation engine (TY2025). Run unmodified as a subprocess.

    License
    AGPL v3
    Pinned
    v2.0.4 · c4c7d72
    Source code(opens in a new tab)

  • Open Tax Document (OTD)

    Tom O'Sullivan, Crimson Tree Software

    K-1 data standard, taxonomy, validator and PDF → OTD extraction pipeline.

    License
    CC BY 4.0
    Pinned
    be6452a
    Specification(opens in a new tab)

Ground rules

  • Synthetic data Every client, K-1 and figure in this app is made up.
  • Dry run · never sent to IRS E-file runs against a fake transmitter. Nothing is sent to the IRS.
  • Research optional Research uses an external research API when a key is set.