AI engineering glossary · Web APIs HTTP
What is 422 Unprocessable Content?
422 Unprocessable Content (also called 422 Unprocessable Entity): The status code meaning the request is well formed but its contents fail validation rules, such as an age of -5 or an invalid email. Frameworks like FastAPI use it for schema errors and list the failing fields.
422 Unprocessable Content: an example
A valid JSON body with {"age": "abc"} where a number is required returns 422.
Related terms
More Web APIs HTTP terms
- 429 Too Many Requests
- 500 Internal Server Error
- 502 Bad Gateway
- 503 Service Unavailable
- 504 Gateway Timeout
- Accept header
- Access token
- API
Where you learn it
422 Unprocessable Content is part of the AI Engineering Program, which teaches it with notes, a hands-on lab and an exam. The first lesson is free.