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	string	Yes	Receipt format version. Currently "1.0".
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	number	Yes	Unix millisecond 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": "1.0",
  "receipt_id": "0195f2c6-9a2b-7c4d-8e1f-3a5b7c9d1e2f",
  "operation_id": "0195f2c6-8f4e-7a1b-9c3d-2e4f6a8b0c1d",
  "org_id": "org_acme",
  "agent_id": "agent_underwriter",
  "server_received_at": 1772287201000,
  "seq_no": 42,
  "chain_hash": "<base64url chain hash>",
  "queue_message_id": "<queue message id>",
  "receipt_hash": "<base64url receipt hash>",
  "elydora_kid": "<Elydora signing key id>",
  "elydora_signature": "<base64url Ed25519 signature>"
}

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.