Releases and Version Compatibility
OpenHTF release history from 1.0 (2016) to 1.6.x (2025), Python version requirements per release, what changed, and which release this documentation is verified against.
Last updated · Verified with OpenHTF 1.6.1
OpenHTF is released on PyPI from github.com/google/openhtf. This page tracks the releases that matter for compatibility; the changelog for TofuPilot's own products is at tofupilot.com/changelog.
Documentation version
Every page on this site shows a Verified with OpenHTF x.y.z line under its title. The examples were run against that release, currently 1.6.1, on Python 3.12. When a page has no such line its content is version-independent.
Release history
| Release | Date | Python | Notes |
|---|---|---|---|
| 1.6.1 | 2025 | ≥ 3.10 | Current PyPI release. Packaging fixes on top of 1.6.0. |
| 1.6.0 | March 2025 | ≥ 3.10 | "Roll-up" release after two and a half years: Python 3.10 minimum, protobuf>=5.28, tornado>=6,<6.5, modern pyproject.toml, many accumulated fixes. |
| 1.5.2 | October 2022 | ≥ 3.7 | setup.py fixes. Last release for Python 3.7–3.9. |
| 1.5.1 | October 2022 | ≥ 3.7 | Deployment workflow fix. |
| 1.5.0 | October 2022 | ≥ 3.7 | Numerous features and bug fixes; dropped Python 2. Diagnoses, branches and checkpoints matured in this line. |
| 1.3.0 | May 2018 | 2.7 / 3 | Improved logging, new Angular web GUI (the Operator UI still used today). |
| 1.2.x | January–March 2018 | 2.7 / 3 | Incremental fixes. |
| 1.1.0 | July 2017 | 2.7 | |
| 1.0.0 – 1.0.3 | August–September 2016 | 2.7 | Initial open-source releases. |
master carries version 1.6.2 in pyproject.toml (unreleased as of September 2026). Install it with pip install git+https://github.com/google/openhtf.git if you need a fix that has not shipped.
Upgrading from 1.5 to 1.6
- Python: 3.10 or newer is required. Recreate the virtual environment.
- protobuf 5: only matters if you use
mfg_inspectoror the proto output; regenerate any custom_pb2modules. - tornado < 6.5: if another package in the environment needs a newer tornado, isolate OpenHTF in its own venv.
- API: no intentional breaking changes to phases, measurements, plugs or output callbacks. Test scripts written for 1.5 run unchanged.
Version pinning
Pin OpenHTF and instrument libraries per station:
openhtf==1.6.1See Installation and Production deployment.
Related
FAQ
Answers to common OpenHTF questions and errors — blank Operator UI, unset measurements failing, ERROR vs FAIL outcomes, phase timeouts, tornado version conflicts, Python support, and how OpenHTF relates to TofuPilot.
Manufacturing Test Analytics
Monitor your test's first-pass yield (FPY) and capability index (Cpk) at the measurement level using TofuPilot with OpenHTF.
