My family tree became a 404, so I built one that lives on my computer

This is a story about an open-source project called Tell the Tree, which helps people build their own family trees using plain sentences on their own computers. The creator of the project, named Carla, was inspired by her own family tree that turned into a broken link when the genealogy website she used shut down.

Tell the Tree uses a small language model called Gemma 4 E2B, running on the user's computer through a tool called Ollama. Users can input sentences in English or Italian describing their family relationships, like "Allegra is the daughter of Claire and Lord Byron." The code then processes these sentences, checking for things like cycles, impossible dates, and conflicting parents. If the code is unsure about something, it asks the user.

For example, if the tree has two people named Percy, the code will ask the user which one they mean before adding the new relationship. The user can also add, edit, or delete people manually, add photos, search for specific individuals, and switch between different tree layouts. When the user is satisfied with their tree, they can export it in GEDCOM format, a standard file type used by genealogy programs.

The project was built as part of the DEV's Ghost in the Machine challenge in October 2026. Carla tested the model using 15 different sentences, including some in spoken Italian, and found that Gemma 4 E2B performed better than another model called Gemma 4 E4B. She also tested the code against a hidden set of 6 sentences, finding that the model got 5 out of 6 correct while the code got only 1 out of 6.

Overall, Tell the Tree provides a solution to the problem of losing family trees when the websites they're stored on shut down. By allowing users to build and store their trees locally, it ensures that their family history remains accessible and secure.