biological decay-based memory forgetting
Implements spaced repetition and memory decay using biological forgetting curves (Ebbinghaus-inspired) rather than simple TTL or LRU eviction. Memories degrade probabilistically over time based on access frequency and recency, with recall probability decreasing according to a decay function. The system tracks memory age, access count, and last-accessed timestamp to compute dynamic decay rates, enabling memories to fade naturally while high-value memories remain retrievable longer.
Unique: Uses biological forgetting curves (Ebbinghaus decay model) to probabilistically fade memories over time based on recency and frequency, rather than fixed TTL or LRU eviction. Decay is parameterized and continuous, not discrete, allowing smooth degradation of memory confidence.
vs alternatives: More cognitively plausible than simple vector DB retrieval + fixed context windows; enables natural forgetting without explicit memory management, but trades determinism and recall accuracy (52%) for more human-like behavior.
time-aware memory indexing and retrieval
Maintains a time-indexed memory store where each memory record includes creation timestamp, last-access timestamp, and access frequency counters. Retrieval queries compute decay scores on-the-fly by evaluating the memory's age against a decay function, then filter/rank results by decay probability. The system supports both semantic similarity search (via embeddings) and temporal filtering, allowing queries like 'retrieve memories from the last week' or 'find facts I've accessed frequently'.
Unique: Combines semantic embedding-based retrieval with temporal decay scoring, computing memory confidence dynamically based on age and access patterns. Decay is applied at query time rather than pre-computed, enabling adaptive confidence thresholds.
vs alternatives: More sophisticated than simple vector DB retrieval (which ignores time) and simpler than full knowledge graph systems; enables temporal reasoning without requiring explicit memory consolidation or summarization logic.
probabilistic memory filtering by decay threshold
Implements a confidence-based filtering mechanism where memories are included in the agent's context window only if their decay probability exceeds a configurable threshold. The system computes decay probability as a function of memory age, access frequency, and a parameterized decay curve (e.g., exponential, power-law). Memories below the threshold are excluded from LLM prompts, effectively implementing 'soft forgetting' where low-confidence memories don't influence reasoning but remain in storage for potential recovery.
Unique: Uses probabilistic decay scores as a filtering mechanism rather than hard deletion, allowing memories to fade gracefully from context while remaining recoverable. Threshold-based filtering decouples memory storage from context injection.
vs alternatives: More nuanced than fixed-size context windows (which discard memories arbitrarily) and simpler than learned importance weighting; enables confidence-aware context selection without training.
access frequency tracking for memory reinforcement
Tracks how many times each memory has been retrieved or referenced by the agent, using access count as a signal of memory importance. Frequently accessed memories decay more slowly (higher half-life) than rarely accessed ones, implementing a reinforcement mechanism where 'using' a memory strengthens it. The system updates access counts on every retrieval and incorporates them into the decay function, so memories that are repeatedly useful resist forgetting longer.
Unique: Uses access frequency as an implicit importance signal, slowing decay for frequently-retrieved memories without requiring explicit user annotation. Access count is incorporated directly into the decay function rather than as a separate ranking signal.
vs alternatives: Simpler than learned importance models (no training required) but more sophisticated than uniform decay; enables emergent memory hierarchies based on agent behavior.
embedding-based semantic memory retrieval
Converts memory text to dense vector embeddings (via OpenAI, Anthropic, or local embedding model) and stores them in a vector index. Retrieval queries are also embedded and matched against the index using cosine similarity or other distance metrics, enabling semantic search where 'what did we discuss about budgets' retrieves memories about 'financial planning' even without exact keyword match. The system integrates embedding generation with the decay filtering pipeline, so retrieved memories are ranked by both semantic relevance and decay probability.
Unique: Integrates semantic embedding-based retrieval with decay probability scoring, ranking memories by both semantic relevance and temporal confidence. Decay filtering is applied post-retrieval, not pre-computed, allowing dynamic threshold adjustment.
vs alternatives: More flexible than keyword-based search (handles paraphrasing and semantic drift) but more expensive and slower than simple BM25; enables natural language queries without requiring structured memory schemas.
configurable decay function parameterization
Allows users to specify decay function parameters (half-life, shape, minimum confidence floor) that control how quickly memories fade. The system supports multiple decay models (exponential, power-law, or custom functions) and applies them uniformly across all memories. Parameters can be adjusted globally or per-memory-type, enabling domain-specific tuning (e.g., facts decay slower than opinions). The decay function is evaluated at query time using memory age and access frequency to compute current confidence probability.
Unique: Exposes decay function parameters as configuration rather than hardcoding them, enabling users to experiment with different decay models and tune memory persistence without code changes. Supports multiple decay function families (exponential, power-law, custom).
vs alternatives: More flexible than fixed decay rates (common in simple TTL systems) but requires manual tuning; enables domain-specific memory policies without requiring ML-based importance learning.
memory consolidation and summarization (inferred capability)
Based on the 52% recall metric and biological memory inspiration, the system likely implements or supports memory consolidation where related memories are periodically merged or summarized to reduce storage and improve retrieval efficiency. This would involve identifying semantically similar memories, generating summaries, and replacing clusters with consolidated records. The consolidation process would preserve high-level information while discarding redundant details, mimicking biological memory consolidation during sleep.
Unique: unknown — insufficient data on consolidation implementation; inferred from biological memory inspiration and 52% recall metric suggesting information loss through consolidation
vs alternatives: More sophisticated than simple TTL-based forgetting; enables long-term memory without unbounded storage growth, but requires careful tuning to avoid losing important details.