Diagnostics

Mosaico stores sequences with arbitrary metadata, which makes it compatible with any tool that produces structured .mcap snapshots or injects records via the SDK.

ros2_medkit

ros2_medkit is a ROS 2 node that monitors /diagnostics topics, holds recent sensor data in a ring buffer, and writes an .mcap snapshot when a fault is confirmed. Only the window around the fault event is persisted.

The snapshot is ingested into Mosaico with structured metadata: robot ID, fault code, severity, and timestamp. It is stored as a regular sequence and can be queried using the standard SDK.

For a walkthrough, see ros2_medkit and Mosaico: Fault Forensics.