Batching is supported for Firebird 4 (and above). The work is handled by FbBatchCommand class. It has similar API surface as FbCommand. The usage should feel familiar.
Calling the ExecuteNonQuery/ExecuteNonQueryAsync does not throw an exception, should the exception happen on server while processing the data. Instead the returned FbBatchNonQueryResult object should be used to check the status. The EnsureSuccess method or AllSuccess property can be used for global check. Further enumeration gives detailed information.
Properties MultiError, ReturnRecordsAffected and BatchBufferSize allow for behavior fine-tuning (these represent TAG_MULTIERROR, TAG_RECORD_COUNTS and TAG_BUFFER_BYTES_SIZE in BPB).
When dealing with huge batches of possible unlimited size, it's good to use ComputeCurrentBatchSize/ComputeCurrentBatchSizeAsync to make sure the batch is not over BatchBufferSize. However calling ComputeCurrentBatchSize/ComputeCurrentBatchSizeAsync is not cheap and should be handled accordingly.
At the moment batching is not supported for Firebird Embedded. The progress is tracked here.
Using (real) blobs as values is not supported. Regular byte[], string, etc. values and the implicit conversions work just fine. The progress is tracked here.
Examples can be found in FbBatchCommandTests.