curl --request POST \
  --url "https://directory.example.com/dids/did%3Atalaria%3A1111111111111111111111/document/key-agreements" \
  --header "Content-Type: application/json" \
  --data '{
  "did": "did:talaria:1111111111111111111111",
  "action": "AddKeyAgreement",
  "key_agreement": {
    "id": "did:talaria:1111111111111111111111#agreement",
    "type": "Multikey",
    "controller": "did:talaria:1111111111111111111111",
    "publicKeyMultibase": "<public-key>"
  },
  "nonce": "<nonce>",
  "valid_until": "2026-07-16T12:05:00Z",
  "signer_key_id": "did:talaria:1111111111111111111111#root",
  "canonical_payload": "<payload>",
  "signature": "<signature>"
}'

{
  "status": "accepted",
  "did": "did:talaria:1111111111111111111111",
  "action": "AddKeyAgreement",
  "tx_hash": "<transaction-hash>",
  "message": "DID document modification submitted"
}