How to Stop Work When a Request Is Cancelled

Client disconnected while your API is still doing expensive work?

Pass the CancellationToken.

public async Task<IActionResult> GetOrders(
    CancellationToken cancellationToken)
{
    var orders = await context.Orders
        .ToListAsync(cancellationToken);

    return Ok(orders);
}

Propagate the token through operations that support cancellation:

• Database queries
• HTTP calls
• Background operations
• Delays
• Long-running async workflows

Cancellation doesn't make every operation disappear immediately.

It signals downstream operations that the caller no longer needs the result.

If the request is gone, continuing work is often unnecessary.