Letta

Introducing FrontierMemory: a new way to evaluate agent memory through downstream task performance.

While existing memory benchmarks focus on recall (saturated via agentic search), FrontierMemory focuses on how agents learn from experience.

Inkling 2 Small from @thinkymachines scores 60.0% on FrontierMemory, the highest of any US open-weights model, at about $19 per (American) dream.

We've updated FrontierMemory to v1.1, with a larger 750-trajectory corpus that reduces reward hacking and includes a more balanced mix of sources.

Opus 5.5 remains the strongest memory model, with open-weight models like DeepSeek V4.1 Flash, Kimi K3, and GLM-5.3 close behind.

FrontierMemory is now on @FireworksAI_HQ's Specialized Intelligence Index.

Picking a model for a long-running agent? You can now compare how well each one learns from its own past attempts, combined with cost.

View FrontierMemory results under RSI: fireworks.ai/specialized-in…