Versions and provenance

What is versioned

item	meaning
engine version	the software build; stamped into every result and into the session record
algorithm version	a single number, bumped whenever any frozen parameter or algorithm behaviour changes
parameter set	the named, frozen set of constants; the full set of values is copied into every result
stage algorithm versions	the implementation version of each processing stage (for example speed, lap delta, IMU and mount calibration), recorded in each result's provenance
centerline version	hash of the stored centerline; an input of every downstream result
telemetry identity	a SHA-256 hash of each chapter's telemetry track; the session identity is a hash of the chapter hashes. It is the authoritative identity of the data; a video re-uploaded under another name yields the same session

Invalidation

A result is stale when any of algorithm version, parameter-set id, parameter hash or input hashes differs. The video file's fingerprint never invalidates telemetry results.

Reading the Provenance tab

For the analysis on screen it lists: engine version, parameter set and algorithm version, the camera (model, firmware, GPS stream and rate, IMU rate), each chapter's telemetry hash, one row per stage with its algorithm version, inputs, units and notes (e.g. the actual filter rates used), the endpoint-invariant error of every lap pair, and the run log with timestamps.

Reference tables (generated from the engine)

Signed-in users can open the generated reference tables from the Methodology menu in the app: the full parameter set (every constant with its value and meaning), the metric reference (every number the interface can show), and the quality flags with the processing stages. The tables are generated from the same registry the engine serves to the interface; an automated test fails when they drift from the code.