want to attach arbitrary key/value config to a stream and have it persist alongside observations.
first usage of this is record reply #1976 storing original topic names for streams (but I assume this is just first usage, embedding model name for embedding stream would be another example)
store.streams.lidar.metadata.calibration_offset = 3
store.streams.lidar.metadata.set("frame_id", "base_link")
store.streams.lidar.metadata.update({"sensor_model": "mid360", "rate_hz": 10})
store.streams.lidar.metadata["calibration_offset"] # 3distinct from per-observation Observation.tags (dimos/memory2/type/observation.py:57), which is immutable-derive (obs.tag(k=v) returns a new observation). keeping the APIs separate on purpose — observations are immutable, stream metadata is mutable config that's set once and read often.
requirements:
- attribute + dict-style get/set, plus
set() / update() / delete()
- persisted by the backend (sqlite store gets a kv table; null/memory stores keep a dict)
- json-serializable values only at first; reject anything else loudly
- survives store reopen
should we...?
- make it
Notifier-watchable so subscribers get told when metadata changes?
- expose it on the
Backend directly so transforms/embedders can read it (e.g. a vectorstore reads embedding_model from stream metadata)?
related: #1652 (postgres store would also need this).
want to attach arbitrary key/value config to a stream and have it persist alongside observations.
first usage of this is record reply #1976 storing original topic names for streams (but I assume this is just first usage, embedding model name for embedding stream would be another example)
distinct from per-observation
Observation.tags(dimos/memory2/type/observation.py:57), which is immutable-derive (obs.tag(k=v)returns a new observation). keeping the APIs separate on purpose — observations are immutable, stream metadata is mutable config that's set once and read often.requirements:
set()/update()/delete()should we...?
Notifier-watchable so subscribers get told when metadata changes?Backenddirectly so transforms/embedders can read it (e.g. a vectorstore readsembedding_modelfrom stream metadata)?related: #1652 (postgres store would also need this).