Observability Events

Mnemosyne emits structured JSON logs through src/observability/logger.ts and operation metrics through src/observability/metrics.ts.

Recall

recall_start

• query — original caller query
• scope — requested memory scope
• intent — resolved recall intent

layer_query

• layer — queried memory layer
• scope — requested memory scope
• duration_ms — elapsed time spent in the layer adapter
• ok — whether the layer call returned a successful recall result

layer_degraded

• layer — degraded, skipped, or failed layer
• scope — requested memory scope
• reason — machine-readable degradation reason
• detail — optional human-readable detail

recall_end

• duration_ms — elapsed recall operation time
• hit_count — returned hit count, or 0 for failed recalls
• layers_queried — layers reported as queried, or [] for pre-dispatch failures
• scope — requested memory scope
• intent — resolved recall intent
• ok — whether recall succeeded
• error_code — present when recall failed with a code
• error_layer — present when recall failed

Remember

remember_start

• scope — requested memory scope
• layer — resolved target layer
• content_hash — sha256 hash of the content text

remember_end

• duration_ms — elapsed remember operation time
• layer — resolved target layer
• scope — requested memory scope
• ok — whether remember succeeded

Metrics

• recall_duration_ms — histogram recorded once per recall() call.
• remember_duration_ms — histogram recorded once per remember() call.
• layer_degraded_total — counter incremented for each detected degradation, skipped layer, or layer failure.