Elydora Operation Record (EOR)

The EOR is the unit of accountability in the Elydora protocol: a signed, immutable record of one agent action.

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	string	Yes	Protocol version. Currently "1.0".
operation_id	string	Yes	Client-generated UUIDv7. 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	number	Yes	Unix timestamp in milliseconds when the agent created the operation.
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	object	Yes	JSON object describing the entity or resource the operation acts upon.
action	object	Yes	JSON object describing the action performed.
payload	object \| string \| null	Yes	Operation-specific data: a JSON object, a string, or null.
payload_hash	string	Yes	Base64url SHA-256 of the canonical (RFC 8785) payload.
prev_chain_hash	string	Yes	Chain hash of this agent's previous operation. The first operation uses the genesis constant, 32 zero bytes in base64url.
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 covers the JSON Canonicalization Scheme (RFC 8785) serialization of every field except signature.

Example EOR

json

{
  "op_version": "1.0",
  "operation_id": "0195f2c6-8f4e-7a1b-9c3d-2e4f6a8b0c1d",
  "org_id": "org_acme",
  "agent_id": "agent_underwriter",
  "issued_at": 1772287200000,
  "ttl_ms": 30000,
  "nonce": "qL3xV9pZ2mK8wR4t",
  "operation_type": "loan.approve",
  "subject": { "id": "borrower:BRW-2026-0042", "type": "borrower" },
  "action": { "name": "approve", "type": "decision" },
  "payload": {
    "loanId": "LN-2026-001",
    "amount": 50000,
    "currency": "USD"
  },
  "payload_hash": "<base64url SHA-256 of the canonical payload>",
  "prev_chain_hash": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
  "agent_pubkey_kid": "agent_underwriter-key-1",
  "signature": "<base64url Ed25519 signature>"
}

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.