Elydora Acknowledgement Receipt (EAR)

The EAR is Elydora's server-side attestation that an operation was received, validated, sequenced, and permanently recorded. It is signed by Elydora's own Ed25519 key.

Structure

Field	Type	Required	Description
receipt_version	number	Yes	Receipt format version. Currently 1.
receipt_id	string	Yes	Unique identifier for this receipt.
operation_id	string	Yes	The operation ID this receipt acknowledges.
org_id	string	Yes	Organization identifier.
agent_id	string	Yes	Agent that submitted the operation.
server_received_at	string	Yes	ISO 8601 timestamp of server receipt.
seq_no	number	Yes	Global sequence number within the organization.
chain_hash	string	Yes	The computed chain hash after this operation.
queue_message_id	string	Yes	Internal message queue ID for traceability.
receipt_hash	string	Yes	SHA-256 hash of the canonical receipt (excluding Elydora signature).
elydora_kid	string	Yes	Key ID of Elydora's signing key used for this receipt.
elydora_signature	string	Yes	Ed25519 signature by Elydora over the receipt_hash.

Example EAR

json

{
  "receipt_version": 1,
  "receipt_id": "rcpt_xyz789",
  "operation_id": "550e8400-e29b-41d4-a716-446655440000",
  "org_id": "org_acme",
  "agent_id": "agent_underwriter",
  "server_received_at": "2026-02-28T14:00:01Z",
  "seq_no": 42,
  "chain_hash": "sha256:ghi789...",
  "queue_message_id": "msg_001",
  "receipt_hash": "sha256:receipt_hash_abc...",
  "elydora_kid": "elydora-signing-key-001",
  "elydora_signature": "base64:elydora-ed25519-sig..."
}

Independent Verification

The EAR can be verified independently using Elydora's public keys from the JWKS endpoint:

Fetch the JWKS from /.well-known/elydora/jwks.json
Find the key matching elydora_kid
Recompute receipt_hash from the receipt fields
Verify the Ed25519 signature over the receipt_hash

Properties

Server attestation — Proves Elydora received and processed the operation.
Sequence ordering — The seq_no provides a total ordering of operations within an organization.
Non-repudiation — Elydora cannot deny issuing the receipt, as it is signed with their key.
Offline verification — Anyone with the JWKS can verify the receipt without contacting the API.