validate
01
OnValidateCreateAsync
Check uniqueness, business rules, and constraints before any write. Return Error to abort cleanly before the DB is touched.
returns ErrorOr<Success>
validate
02
OnValidateUpdateAsync
Validate the fully merged entity. Receives both the original and the enriched entity — compare them to enforce business rules.
returns ErrorOr<Success>
validate
03
OnValidateDeleteAsync
Guard against invalid deletions: check relations, enforce cascade rules, or block soft-deletes when conditions aren't met.
returns ErrorOr<Success>
map
04
OnMapCreateAsync
Enrich with server-side computed fields: slugs, tenant IDs, audit timestamps. These values must never come from the client.
returns ErrorOr<TEntity>
map
05
OnMapUpdateAsync
Recompute derived fields after an update: re-slug, recalculate denormalized fields. Receives original + request.
returns ErrorOr<TEntity>
map
06
OnMapToDetailAsync
Build the full single-item response. Compute derived fields, format values, load relations. Called by GetByIdAsync and CreateAsync.
returns ErrorOr<TDetail>
map
07
OnMapToSummaryAsync
Build the lightweight list response. Smaller payloads, cleaner contracts. Called by both pagination strategies (offset and cursor). Keep this lean — omit arrays and large nested objects.
returns ErrorOr<TSummary>
cache
08
GetCacheKey
Key for a single entity by ID. Default: "{type}:{id}". Scoped per repository — no conflicts across resources.
returns string
cache
09
GetPagedCacheKey
Key for an offset-paged list result. Default: "{type}:paged:p{page}:s{size}". Override for custom filter or tenant keys.
returns string
cache
10
GetCursorCacheKey
Key for a cursor-paged list result. Default includes cursor, page size, and direction. Override for tenant-scoped or filtered keys.
returns string
cache
11
GetInvalidationTags
Tags to wipe on any write. Default: entity-type + ID tag. Override to add category or tenant tags. Union of old+new applied on update to cover field changes.
returns IEnumerable<string>
cache
12
GetCacheTtl
Bound how long responses are cached. Return null for the global default. Set shorter than presigned URL expiry to avoid serving stale S3 links.
returns TimeSpan?
error
13
GetNotFoundError
Override to return a domain-specific not-found error (e.g. ProductErrors.NotFound(id)) instead of the generic one. Called on every null by-ID result.
returns Error
after
14
OnAfterCreateAsync
Runs after a successful insert + cache invalidation. Fire events, send notifications, invalidate external systems, or trigger background jobs.
returns Task
after
15
OnAfterUpdateAsync
Runs after a successful update + cache invalidation. Propagate change notifications, sync projections, or trigger search reindexing.
returns Task
after
16
OnAfterDeleteAsync
Runs after a confirmed delete + cache invalidation. Delete linked S3 objects, emit deletion events, or cascade side effects to other aggregates.
returns Task
rollback
17
OnCreateFailedAsync
Called when the DB insert fails after OnMapCreateAsync already ran. Roll back side effects — e.g. delete an S3 object that was just uploaded.
returns Task
rollback
18
OnUpdateFailedAsync
Called when the DB replace fails. Roll back any side effects performed during OnMapUpdateAsync before the database was touched.
returns Task
rollback
19
OnDeleteFailedAsync
Called when the DB delete fails after OnValidateDeleteAsync passed. Roll back any compensating actions triggered during validation before the delete ran.
returns Task
