Module activation 

SYNAPSE spreading activation retrieval over the entity graph.

Implements the spreading activation algorithm from arXiv 2601.02744, adapted for the zeph-memory graph schema. Seeds are matched via fuzzy entity search; activation propagates hop-by-hop with:

• Exponential decay per hop (decay_lambda)
• Edge confidence weighting
• Temporal recency weighting (reuses GraphConfig.temporal_decay_rate)
• Lateral inhibition (nodes above inhibition_threshold stop receiving activation)
• Per-hop pruning to enforce max_activated_nodes bound (SA-INV-04)
• MAGMA edge type filtering via edge_types parameter

Structs

ActivatedFact

A graph edge traversed during spreading activation, with its activation score.

ActivatedNode

A graph node that was activated during spreading activation.

HelaFact

A graph edge surfaced by HL-F5 spreading activation (#3346), scored by path_weight × max(cosine_query_to_endpoint, 0.0).

HelaSpreadParams

Parameters for HL-F5 spreading activation retrieval.

SpreadingActivation

Spreading activation engine parameterized from SpreadingActivationParams.

SpreadingActivationParams

Parameters for spreading activation. Mirrors SpreadingActivationConfig but lives in zeph-memory so the crate does not depend on zeph-config.

Functions

hela_spreading_recall

HL-F5 BFS spreading activation from the top-1 ANN anchor node (#3346).