## Bloomreach Engagement API returns HTTP 400 error
Generally, this error is usually returned for API requests, which sent somehow incorrectly formatted request body (usually JSON).
Common root causes might be:
Valid JSON format but invalid JSON content (missing mandatory fields, etc.).
Invalid JSON format.
The first root cause requires carefully reading specific API endpoint documentation, especially mandatory fields.
The second root cause might return the following example of a general HTTP 400 error.
In such a case, try to verify whether your request body is not automatically compressed by **gzip**. If yes, disable gzip API compression.