Identity Engine SDK

Type: SDK

Value: Gives agent builders a persistent identity layer with an immutable core, evolving state, append-only history, and drift checks.

Current Status

Complete as a local TypeScript SDK slice. It is usable from local Node projects after install/build, with file-backed persistence and deterministic drift checks.

Implemented Local Slice

• Identity core with id, name, purpose, creation timestamp, and SHA-256 fingerprint
• Mutable state updates that preserve the immutable core and increment versions
• Append-only journal entries for state updates, drift checks, and notes
• File-backed identity store for save, load, list, journal read/write, and delete
• Lexical goal-drift check with configurable threshold
• Unit tests for identity creation, immutable updates, drift checks, persistence, journals, listing, and delete

Commands

npm install
npm test
npm run build

SDK Surface

import { FileIdentityStore, checkDrift, createIdentity, updateState } from '@blair/identity-engine-sdk';

const store = new FileIdentityStore('./.identity-engine');
const identity = createIdentity('Support Agent', 'Help customers resolve account access issues');

await store.save(identity);

const { identity: updated, entry } = updateState(identity, { tone: 'calm', escalation: 'human-review' });
await store.save(updated);
await store.appendJournal(updated.core.id, entry);

const { result } = checkDrift(updated, 'Troubleshooting account access and login recovery', 0.4);

Current Limits

• This is a local SDK slice, not a hosted identity dashboard or account service.
• No public npm publication, hosted API, auth, billing, team workspace, live checkout, or managed storage is included.
• Drift scoring is deterministic lexical overlap, not embedding or LLM-based semantic scoring.
• The file store is developer-local JSON/JSONL storage, not encrypted remote storage or compliance-grade retention.

Verification

Fresh suite verification on 2026-05-28:

• npm test passed, 14/14 tests.
• npm run build passed.