Elydora Operation Record (EOR)

The EOR is the fundamental unit of accountability in the Elydora protocol. It is a signed, immutable record that captures a single agent action with cryptographic integrity.

Structure

An EOR contains all the metadata needed to identify, verify, and chain-link an operation. Every field is included in the signature computation.

Field	Type	Required	Description
op_version	number	Yes	Protocol version. Currently 1.
operation_id	string	Yes	Client-generated UUID v4. Must be globally unique.
org_id	string	Yes	Organization identifier that the agent belongs to.
agent_id	string	Yes	Identifier of the agent performing the operation.
issued_at	string	Yes	ISO 8601 timestamp when the operation was created by the agent.
ttl_ms	number	Yes	Maximum time (ms) between issued_at and server receipt. Prevents delayed replay.
nonce	string	Yes	Random value for replay protection. Must be unique per agent.
operation_type	string	Yes	Domain-specific type string (e.g. loan.approve, trade.execute).
subject	string	Yes	The entity or resource the operation acts upon.
action	string	Yes	The action performed (e.g. approve, reject, flag).
payload	object	Yes	Arbitrary JSON payload with operation-specific data.
payload_hash	string	Yes	SHA-256 hash of the canonicalized payload JSON.
prev_chain_hash	string \| null	Yes	SHA-256 chain hash of this agent's previous operation. null for the first operation.
agent_pubkey_kid	string	Yes	Key ID (kid) of the agent's Ed25519 signing key.
signature	string	Yes	Ed25519 signature over the canonical EOR (excluding the signature field itself).

Canonical Form

The signature is computed over the canonical JSON representation of the EOR. Canonical form means all fields (except signature) are sorted alphabetically and serialized with no whitespace.

Example EOR

json

{
  "op_version": 1,
  "operation_id": "550e8400-e29b-41d4-a716-446655440000",
  "org_id": "org_acme",
  "agent_id": "agent_underwriter",
  "issued_at": "2026-02-28T14:00:00Z",
  "ttl_ms": 30000,
  "nonce": "a1b2c3d4e5f6",
  "operation_type": "loan.approve",
  "subject": "LN-2026-001",
  "action": "approve",
  "payload": {
    "loanId": "LN-2026-001",
    "amount": 50000,
    "currency": "USD"
  },
  "payload_hash": "sha256:e3b0c44298fc1c149afbf4c8996fb924...",
  "prev_chain_hash": "sha256:d7a8fbb307d7809469ca9abcb0082e4f...",
  "agent_pubkey_kid": "kid_abc123",
  "signature": "base64:ed25519-signature-bytes..."
}

Security Properties

Authenticity — The Ed25519 signature proves the EOR was created by the holder of the agent's private key.
Integrity — Any modification to any field invalidates the signature.
Non-repudiation — The agent cannot deny creating the operation, as only they possess the private key.
Ordering — The prev_chain_hash field creates a verifiable ordering of operations per agent.
Freshness — TTL and nonce prevent replay attacks and stale submissions.