How would you use EF Core rowversion to prevent lost updates in an API?

Handle EF Core rowversion concurrency conflicts in an API

Explains optimistic concurrency with EF Core rowversion tokens, API conflict responses, and safe retry boundaries.

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I mark a SQL Server rowversion property as an EF Core concurrency token and return its encoded value when the client reads the resource. The client sends that version with the update, and EF Core includes the original token in the update predicate. If another write changed the row, zero rows are affected and SaveChangesAsync throws DbUpdateConcurrencyException. The API returns a conflict or failed precondition instead of silently overwriting the newer state.

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Optimistic concurrency, rowversion, concurrency tokens, DbUpdateConcurrencyException, conflict responses, and retry behavior.

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Why this question matters
Lost updates are easy to miss in normal CRUD demos. This drill connects SQL rowversion behavior to the API contract users actually experience.
I mark a SQL Server rowversion property as an EF Core concurrency token and return its encoded value when the client reads the resource. The client sends that version with the update, and EF Core includes the original token in the update predicate. If another write changed the row, zero rows are affected and SaveChangesAsync throws DbUpdateConcurrencyException. The API returns a conflict or failed precondition instead of silently overwriting the newer state.
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Details

Using last-write-wins for important updates.
Catching concurrency exceptions and retrying every update blindly.
Only checking the version in the frontend.
Assuming one rowversion protects a multi-row invariant.

How would you use EF Core rowversion to prevent lost updates in an API?

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