# Which Problems Are Solved
As part of https://github.com/zitadel/zitadel/issues/11917 we want to
introduce error slugs so (API) clients can rely on stable,
machine-readable errors and act accordingly.
# How the Problems Are Solved
- Added a `NewSlug` helper function in the domain package.
- Added `ErrorDetails` to the `ZitadelError`
- Added an `zitadel.error.v2.ErrorDetail` proto message
- Updated the connectRPC error interceptor to map new slug based errors
to the new `ErrorDetail`
- Defined some common slugs and error functions like internal errors
- Defined (session) specific slugs used in the `DeleteSession` and
`CheckUser` functions and replaced old implementations
- Updated integration tests to check specific errors if the relation
database feature is enabled
- Updated doc and guideline to reflect the latest changes and decisions
- Updated DeleteSession endpoint API to list possible slugs
# Additional Changes
None
# Additional Context
- closes#11957
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Co-authored-by: Wim Van Laer <wim+github@zitadel.com>