HHT Diary · open mobility tools
Every trip tells a story.
HHT Diary is an open-source organization building local-first tools that turn everyday movement into travel data people can understand, correct and own, and that researchers can check line by line.
Led by Zhanchao Yang · Apache 2.0 · github.com/hhtdiary
Who we are
Travel data that people can see, check and own.
Where we go says a great deal about our lives, yet the tools that record it usually keep the data on someone else's server, and the tools researchers use to study travel are expensive and closed. HHT Diary is an open-source effort to make travel-behaviour data collection more accessible, transparent, affordable and user-controlled, for everyday people and for the researchers who plan our cities.
Free
No subscription, paid tier, ads or data resale.
Local-first
Data stays on the person's device until they choose to export it.
Transparent
Open code, documented rules, and accuracy measured in public.
Honest
Every page separates what exists today from what is only planned.
What we build
Products, and the open engine they share.
The organization sets the principles and the shared data model; each product is something you install and run. There is one product today.
Product
TripLibre
A free, open-source travel diary for iPhone. It rebuilds each day into visits, trips and modes, keeps the data on the phone, and exports it for analysis.
Available · build from source
Visit TripLibre →Shared foundation
HHTCore
The Swift package behind TripLibre: collection, inference, corrections and export. Any future HHT Diary tool would reuse it, so that data from all of them can be analysed the same way.
Available
Read the architecture →Next
A research edition
A study-ready edition with consent, fixed settings and a controlled hand-over, kept apart from the personal app. Not built, and not promised.
Exploratory
See the roadmap →Explore
Where to go from here.
Products
What you can use today, and how the products relate.
Browse products →Vision
Why we exist, the principles we hold, and what we are not.
Read the vision →Roadmap
Three workstreams, with honest Now, Next and Exploratory labels.
See the roadmap →About
Who leads HHT Diary, how to get in touch, and where the code lives.
About us →Built in the open
Read every line that touches your data.
Everything HHT Diary makes is Apache 2.0 licensed. Ideas start as GitHub issues, and accuracy is measured in public (on a small sample so far).