Error handling

The Petstore API uses conventional HTTP status codes. Codes in the 2xx range indicate success, 4xx indicate a client error, and 5xx indicate a server error.

For the three playground GET operations, see response tables in petstore-playground.json (invalid status on findByStatus, login failures, and server errors).

HTTP status codes

Code	Meaning
200	Success
400	Bad request. Check your parameters.
401	Unauthorized. Invalid or missing credentials.
404	Resource not found (pet, order, or user).
422	Validation exception. Invalid input.
500	Server error. Retry with exponential backoff.

Validation errors

Invalid input often returns 400 or 422 with a JSON body:

{
  "code": 400,
  "type": "error",
  "message": "Invalid ID supplied"
}

Playground-oriented examples

Invalid status on find by status

curl -w "\nHTTP %{http_code}\n" "https://petstore3.swagger.io/api/v3/pet/findByStatus?status=invalid"

Login failure (bad password)

curl -w "\nHTTP %{http_code}\n" "https://petstore3.swagger.io/api/v3/user/login?username=theUser&password=wrong"

Handling errors in code

Node.js

const res = await fetch(
  'https://petstore3.swagger.io/api/v3/pet/findByStatus?status=available',
);
if (!res.ok) {
  if (res.status === 400) {
    const err = await res.json();
    console.log(`Bad request: ${err.message}`);
  }
}

Python

import requests

r = requests.get(
    'https://petstore3.swagger.io/api/v3/pet/findByStatus',
    params={'status': 'available'},
)
if not r.ok:
    if r.status_code == 400:
        print(f"Bad request: {r.json().get('message', '')}")

curl

curl -w "\nHTTP %{http_code}\n" "https://petstore3.swagger.io/api/v3/pet/findByStatus?status=available"

Other operations on the sample server

Endpoints such as store orders or pet updates can return additional error patterns. Those operations are not described in the playground OpenAPI file.