curl --request POST \
  --url https://{organization}.rescueconsole.com/api/animals/animals/{id}/relationships \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "related_animal_id": "0a8c5e21-7b3d-4f96-b1e4-92d6c3a8f507",
  "relationship_type": "sibling"
}
'

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    related_animal_id: '0a8c5e21-7b3d-4f96-b1e4-92d6c3a8f507',
    relationship_type: 'sibling'
  })
};

fetch('https://{organization}.rescueconsole.com/api/animals/animals/{id}/relationships', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://{organization}.rescueconsole.com/api/animals/animals/{id}/relationships"

payload = {
    "related_animal_id": "0a8c5e21-7b3d-4f96-b1e4-92d6c3a8f507",
    "relationship_type": "sibling"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

{
  "id": "<string>",
  "related_animal_id": "<string>",
  "relationship_type": "sibling",
  "created_at": "2023-11-07T05:31:56Z",
  "related_name": "<string>",
  "related_species": "<string>",
  "related_status": "<string>"
}

{
  "error": "house_trained must be 1, 0 or null (not assessed)"
}

{
  "error": "house_trained must be 1, 0 or null (not assessed)"
}

{
  "error": "house_trained must be 1, 0 or null (not assessed)"
}

{
  "error": "house_trained must be 1, 0 or null (not assessed)"
}