Mastra’s Observational Memory Tops BEAM
Mastra’s open-source Observational Memory posts the top published BEAM scores at 100K tokens (83.3%) and 1M tokens (80.6%). It compresses long conversations into searchable observations while keeping agent context compact and prompt-cacheable.
This is a strong result for memory architectures, but the 10M-token drop shows retrieval—not summarization—is the real frontier.
- –Observer and Reflector agents maintain chronological notes while a recall tool retrieves older evidence.
- –The system passes roughly 40K tokens to the agent even when conversations reach 10M tokens.
- –BEAM-10M performance falls to 66.4%, near the 68.0% frontier but within a wide error margin.
- –Major failures involve incomplete search, counting across sessions, and confusing assistant-generated advice with user statements.
- –Results are self-reported and depend partly on the answering model, making independent reproduction important.
DISCOVERED
17m ago
2026-11-12
PUBLISHED
1h ago
2026-11-12
RELEVANCE
AUTHOR
mastra