Jens Tonberg Larsson works at Gilion and publishes open-source tools as thejens. His projects explore practical problems around AI agents, including reliable references to identifiers and recording coding sessions on a Garmin watch.[1][2][3]
Start with id-token-nicer →
Links
GitHub Career
Larsson’s public GitHub profile lists Gilion and earlier work at Google, Spotify and Tink. He publishes independent tools under thejens, including software that connects coding-agent workflows to other systems.[1]
Contributions
Making identifiers easier for agents to handle
id-token-nicer converts UUIDs and integer identifiers into word sequences and supports encoding and decoding in Rust and Python. It also offers a substitution mode that replaces UUIDs with short placeholders before a model sees the text, then restores the originals afterward. The aim is to reduce failures caused by agents inventing or mistyping identifiers. Validation can catch some fabricated references, but it cannot determine whether a valid identifier was used in the right context.[2]
A coding session as a Garmin activity
The Garmin tracker reads local Claude Code session files through a local daemon. A watch polls that daemon through a Cloudflare Tunnel and records token and tool rates alongside wrist heart rate in a Garmin activity. It does not need Anthropic credentials. Trying it requires a supported Garmin watch, local software setup and sideloading a watch application.[3]
Tools, writing & talks
Tools
Start here
id-token-nicergithub.comEncodes identifiers as word sequences or substitutes short placeholders before text reaches an AI model.
Read the README’s identifier examples first. They explain the failure being addressed before the Rust and Python integration details; this is more accessible than starting with watch setup.
Publishes repository[2]Original source- Garmin Claude Code Trackergithub.com
Records coding-session metrics and watch heart rate in a Garmin activity.
Publishes repository[3]Original source