Decay Classes Guide

Fine-tune how fast different types of memories fade based on your use case.

Default Decay Classes

Class	Half-Life	λ (rate)	Time to CANDIDATE*
`PERMANENT`	∞	0	Never
`STABLE`	720h (30d)	0.000963	~47 days
`MODERATE`	168h (7d)	0.004126	~11 days
`EPHEMERAL`	24h (1d)	0.028881	~1.5 days
`VOLATILE`	6h	0.115525	~9 hours

*From WORKING (0.70 conf) to CANDIDATE threshold (0.50), assuming no recalls.

Custom Configuration

openclaw.json

{
  "plugins": {
    "entries": {
      "epistemic": {
        "config": {
          "decayClasses": {
            "STABLE": { "halfLife": 1440 },
            "MODERATE": { "halfLife": 336 },
            "EPHEMERAL": { "halfLife": 48 },
            "VOLATILE": { "halfLife": 12 }
          }
        }
      }
    }
  }
}

Half-life values are in hours.

How Classes Are Assigned

The L1 normalizer assigns decay classes based on claim kind:

Claim Kind	Default Decay Class
`identity`	`PERMANENT`
`occupational`	`STABLE`
`preference`	`STABLE`
`relational`	`STABLE`
`behavioral`	`MODERATE`
`temporal`	`EPHEMERAL`
`episodic`	`MODERATE`

Best Practices

Personal assistants: Use longer half-lives (STABLE: 60d, MODERATE: 14d) for maximum memory retention
Customer support: Shorter EPHEMERAL (12h) to clear session context quickly
Research agents: Make most things STABLE; only meeting times should be EPHEMERAL