Archive Writer

The Archive Writer persists raw HL7 bytes to encrypted, append-only storage before mapping mutates or discards fields.

Compliance replay

Regulators and internal audits may require proving what was received. The archive is the immutable source; mapped clinical data is derived from it.

Behaviour

Writes payload + metadata (sender, timestamp, message control id).
Encryption at rest with rotation-friendly keys.
Triggered synchronously from the HL7 Parser success path so nothing mapped is ever lost if mapping fails later.