@nobulex/identity

Agent identity creation, evolution, lineage tracking, and DID management for the Stele covenant framework.

Evolution Policy and computeCarryForward

When an agent's identity evolves (model change, capability change, operator transfer, etc.), reputation may be partially carried forward. The computeCarryForward function returns a value in [0, 1] indicating what fraction of reputation is preserved.

Default Policy (DEFAULT_EVOLUTION_POLICY)

| Change Type | Rate | Description | |-------------|------|-------------| | created | 1.0 | New identity; full reputation | | model_update (same family) | 0.80 | Version bump within same model (e.g. claude-3 → claude-3.1) | | model_update (different family) | 0.20 | Provider or model ID change | | capability_expansion | 0.90 | Adding capabilities | | capability_reduction | 1.0 | Removing capabilities (trust-preserving) | | operator_transfer | 0.50 | Operator key change | | fork | 0.50 | Same as operator transfer | | merge | min(0.90, 0.80) | Merging identities | | minor_update (no model/cap changes) | 0.95 | Metadata-only change | | Unknown | 0.0 | Full rebuild; no carry-forward |

Usage

import { computeCarryForward, evolveIdentity, DEFAULT_EVOLUTION_POLICY } from '@nobulex/identity';

// Check carry-forward before evolving
const rate = computeCarryForward('model_update', currentIdentity, {
  model: { provider: 'anthropic', modelId: 'claude-3', modelVersion: '2.0' },
});
// rate === 0.80 (same family)

// Custom policy
const customPolicy = { ...DEFAULT_EVOLUTION_POLICY, operatorTransfer: 0.75 };
const rate2 = computeCarryForward('operator_transfer', identity, {}, customPolicy);

The reputationCarryForward value is stored in each lineage entry and used by the reputation layer to decay trust across identity evolutions.