celiums/celiums-memory

Adds an append-only SHA-256 chain to agent_journal and a new journal_verify_chain tool. Defense-in-depth against malicious or compromised operators with direct DB access — if anyone tampers with the journal bypassing journal_write, the next verify call surfaces it.

npm install @celiums/[email protected]

What's new

• Schema: agent_journal gains prev_hash text + hash text columns + chain-walk index. Migration is automatic + idempotent.
• journal_write computes SHA-256(id || agent_id || content || written_at || prev_hash) and persists it on every insert.
• New tool journal_verify_chain({ agent_id? }): walks the chain, recomputes, returns { agent_id, total, valid, broken: [{ id, reason, expected_hash?, got_hash?, expected_prev?, got_prev? }] }.

Verified

End-to-end on the private cluster (20 existing entries):

• Chain backfill: 20/20 hashed correctly, valid: true
• Fresh write: new entry chains to predecessor
• Post-hoc UPDATE agent_journal SET content = ...: verify returns valid: false, broken: [{ reason: 'content/timestamp tampered' }]
• Restore content + recompute hash: valid: true

Recommended action

Run journal_verify_chain on each agent_id you have. If valid: true, your journal hasn't been tampered with. If broken is non-empty, the listed entries were modified outside the handler — investigate before trusting them.