Encrypted memory

createEncryptedMemory wraps any existing ChatMemory so the backing store only ever sees opaque ciphertext. Users hold the key; rogue middleware, backups, and even the backing service itself can't read the plaintext. Uses Web Crypto (AES-GCM, 256-bit) — available on Node 20+ and all modern browsers.

Install

Ships with @agentskit/memory.

Wire it up

import { createEncryptedMemory, fileChatMemory } from '@agentskit/memory'

// A 32-byte key. Generate once per user during onboarding and store
// it on their device (iOS Keychain, Android Keystore, OS credential
// manager, browser IndexedDB with key derivation from a passphrase).
const key = crypto.getRandomValues(new Uint8Array(32))

const memory = await createEncryptedMemory({
  backing: fileChatMemory({ path: './sessions/user-42.json' }),
  key,
})

const runtime = createRuntime({ adapter, memory })

On save, every message's content becomes "" and the ciphertext is stashed in metadata.{ciphertext, iv, length}. On load, the process reverses transparently — the agent never knows the encryption is there.

Additional authenticated data (AAD)

Bind ciphertext to context so the same key can't decrypt messages captured from a different tenant / room / session:

const memory = await createEncryptedMemory({
  backing,
  key,
  aad: new TextEncoder().encode(`tenant:${tenantId}`),
})

Idempotent

Already-encrypted messages (tagged with metadata.agentskitEncrypted) are passed through untouched on subsequent saves, so re-reading and re-saving won't double-encrypt.

Key management

• Keys never pass through the backing store — they live on the user's device.
• Different key → decryption fails with OperationError. That's the correct behavior; treat it as "data is lost, key rotation required."
• Pair with Signed audit log for regulator-friendly evidence of who accessed what.

See also

• Persistent memory
• Vector memory adapters