The transactional endpoint may in any response include zero or more status codes, indicating issues or information for the client. Each status code follows the same format: "Neo.[Classification].[Category].[Title]". The fact that a status code is returned by the server does always mean there is a fatal error. Status codes can also indicate transient problems that may go away if you retry the request.
What the effect of the status code is can be determined by its classification.
![[Note]](images/icons/admon/note.png){kind=icon} | Note |
|---|---|
This is not the same thing as HTTP status codes. Neo4j Status Codes are returned in the response body, at the very end of the response. |
| Classification | Description | Effect on transaction |
|---|---|---|
| The Client sent a bad request - changing the request might yield a successful outcome. | None |
| The database failed to service the request. | Rollback |
| The database cannot service the request right now, retrying later might yield a successful outcome. | None |
This is a complete list of all status codes Neo4j may return, and what they mean.
| Status Code | Description |
|---|---|
| The client provided an invalid request. |
| The client provided a request that was missing required fields, or had values that are not allowed. |
| A constraint imposed by the database was violated. |
| The request (directly or indirectly) referred to a constraint that does not exist. |
| The request (directly or indirectly) referred to an index that does not exist. |
| Invalid use of arithmetic, such as dividing by zero. |
| A constraint imposed by the statement is violated by the data in the database. |
| The statement is directly referring to an entity that does not exist. |
| The statement is syntactically valid, but expresses something that the database cannot do. |
| The statement contains invalid or unsupported syntax. |
| The statement is attempting to perform operations on values with types that are not supported by the operation. |
| The statement is referring to a parameter that was not provided in the request. |
| There were concurrent requests accessing the same transaction, which is not allowed. |
| The request referred to a transaction that does not exist. |
| The request (directly or indirectly) referred to an index that is in a failed state. The index needs to be dropped and recreated manually. |
| An unknown failure occurred. |
| The database was unable to execute the statement. |
| The database was unable to start the transaction. |
| The database was unable to commit the transaction. |
| The database was unable to roll back the transaction. |
| An unknown network failure occurred, a retry may resolve the issue. |