diff --git a/http-ui/src/main.rs b/http-ui/src/main.rs
index 5c61d3e75..a29eb8895 100644
--- a/http-ui/src/main.rs
+++ b/http-ui/src/main.rs
@@ -322,7 +322,7 @@ async fn main() -> anyhow::Result<()> {
         // the type hint is necessary: https://github.com/rust-lang/rust/issues/32600
         move |update_id, meta, content:&_| {
             // We prepare the update by using the update builder.
-            let mut update_builder = UpdateBuilder::new();
+            let mut update_builder = UpdateBuilder::new(update_id);
             if let Some(max_nb_chunks) = indexer_opt_cloned.max_nb_chunks {
                 update_builder.max_nb_chunks(max_nb_chunks);
             }
@@ -363,7 +363,7 @@ async fn main() -> anyhow::Result<()> {
                         otherwise => panic!("invalid encoding format {:?}", otherwise),
                     };
 
-                    let result = builder.execute(reader, |indexing_step| {
+                    let result = builder.execute(reader, |indexing_step, update_id| {
                         let (current, total) = match indexing_step {
                             TransformFromUserIntoGenericFormat { documents_seen } => (documents_seen, None),
                             ComputeIdsAndMergeDocuments { documents_seen, total_documents } => (documents_seen, Some(total_documents)),
@@ -382,7 +382,7 @@ async fn main() -> anyhow::Result<()> {
                     });
 
                     match result {
-                        Ok(()) => wtxn.commit().map_err(Into::into),
+                        Ok(_) => wtxn.commit().map_err(Into::into),
                         Err(e) => Err(e.into())
                     }
                 },
@@ -430,7 +430,7 @@ async fn main() -> anyhow::Result<()> {
                         }
                     }
 
-                    let result = builder.execute(|indexing_step| {
+                    let result = builder.execute(|indexing_step, update_id| {
                         let (current, total) = match indexing_step {
                             TransformFromUserIntoGenericFormat { documents_seen } => (documents_seen, None),
                             ComputeIdsAndMergeDocuments { documents_seen, total_documents } => (documents_seen, Some(total_documents)),
diff --git a/src/search/facet/facet_condition.rs b/src/search/facet/facet_condition.rs
index 578344d37..42c2327a9 100644
--- a/src/search/facet/facet_condition.rs
+++ b/src/search/facet/facet_condition.rs
@@ -625,9 +625,9 @@ mod tests {
 
         // Set the faceted fields to be the channel.
         let mut wtxn = index.write_txn().unwrap();
-        let mut builder = Settings::new(&mut wtxn, &index);
+        let mut builder = Settings::new(&mut wtxn, &index, 0);
         builder.set_faceted_fields(hashmap!{ "channel".into() => "string".into() });
-        builder.execute(|_| ()).unwrap();
+        builder.execute(|_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Test that the facet condition is correctly generated.
@@ -654,9 +654,9 @@ mod tests {
 
         // Set the faceted fields to be the channel.
         let mut wtxn = index.write_txn().unwrap();
-        let mut builder = Settings::new(&mut wtxn, &index);
+        let mut builder = Settings::new(&mut wtxn, &index, 0);
         builder.set_faceted_fields(hashmap!{ "timestamp".into() => "integer".into() });
-        builder.execute(|_| ()).unwrap();
+        builder.execute(|_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Test that the facet condition is correctly generated.
@@ -682,13 +682,13 @@ mod tests {
 
         // Set the faceted fields to be the channel.
         let mut wtxn = index.write_txn().unwrap();
-        let mut builder = Settings::new(&mut wtxn, &index);
+        let mut builder = Settings::new(&mut wtxn, &index, 0);
         builder.set_searchable_fields(vec!["channel".into(), "timestamp".into()]); // to keep the fields order
         builder.set_faceted_fields(hashmap!{
             "channel".into() => "string".into(),
             "timestamp".into() => "integer".into(),
         });
-        builder.execute(|_| ()).unwrap();
+        builder.execute(|_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Test that the facet condition is correctly generated.
@@ -732,13 +732,13 @@ mod tests {
 
         // Set the faceted fields to be the channel.
         let mut wtxn = index.write_txn().unwrap();
-        let mut builder = Settings::new(&mut wtxn, &index);
+        let mut builder = Settings::new(&mut wtxn, &index, 0);
         builder.set_searchable_fields(vec!["channel".into(), "timestamp".into()]); // to keep the fields order
         builder.set_faceted_fields(hashmap!{
             "channel".into() => "string".into(),
             "timestamp".into() => "integer".into(),
         });
-        builder.execute(|_| ()).unwrap();
+        builder.execute(|_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Test that the facet condition is correctly generated.
diff --git a/src/update/clear_documents.rs b/src/update/clear_documents.rs
index ac359ba0d..a84596901 100644
--- a/src/update/clear_documents.rs
+++ b/src/update/clear_documents.rs
@@ -4,11 +4,17 @@ use crate::{ExternalDocumentsIds, Index};
 pub struct ClearDocuments<'t, 'u, 'i> {
     wtxn: &'t mut heed::RwTxn<'i, 'u>,
     index: &'i Index,
+    _update_id: u64,
 }
 
 impl<'t, 'u, 'i> ClearDocuments<'t, 'u, 'i> {
-    pub fn new(wtxn: &'t mut heed::RwTxn<'i, 'u>, index: &'i Index) -> ClearDocuments<'t, 'u, 'i> {
-        ClearDocuments { wtxn, index }
+    pub fn new(
+        wtxn: &'t mut heed::RwTxn<'i, 'u>,
+        index: &'i Index,
+        update_id: u64
+    ) -> ClearDocuments<'t, 'u, 'i> {
+
+        ClearDocuments { wtxn, index, _update_id: update_id }
     }
 
     pub fn execute(self) -> anyhow::Result<usize> {
diff --git a/src/update/delete_documents.rs b/src/update/delete_documents.rs
index 6dc4b1cfa..2b67535c9 100644
--- a/src/update/delete_documents.rs
+++ b/src/update/delete_documents.rs
@@ -12,12 +12,14 @@ pub struct DeleteDocuments<'t, 'u, 'i> {
     index: &'i Index,
     external_documents_ids: ExternalDocumentsIds<'static>,
     documents_ids: RoaringBitmap,
+    update_id: u64,
 }
 
 impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
     pub fn new(
         wtxn: &'t mut heed::RwTxn<'i, 'u>,
         index: &'i Index,
+        update_id: u64,
     ) -> anyhow::Result<DeleteDocuments<'t, 'u, 'i>>
     {
         let external_documents_ids = index
@@ -29,6 +31,7 @@ impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
             index,
             external_documents_ids,
             documents_ids: RoaringBitmap::new(),
+            update_id,
         })
     }
 
@@ -64,7 +67,7 @@ impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
         // We can execute a ClearDocuments operation when the number of documents
         // to delete is exactly the number of documents in the database.
         if current_documents_ids_len == self.documents_ids.len() {
-            return ClearDocuments::new(self.wtxn, self.index).execute();
+            return ClearDocuments::new(self.wtxn, self.index, self.update_id).execute();
         }
 
         let fields_ids_map = self.index.fields_ids_map(self.wtxn)?;
diff --git a/src/update/facets.rs b/src/update/facets.rs
index a268cbeaf..522a4d350 100644
--- a/src/update/facets.rs
+++ b/src/update/facets.rs
@@ -24,10 +24,15 @@ pub struct Facets<'t, 'u, 'i> {
     pub(crate) chunk_fusing_shrink_size: Option<u64>,
     level_group_size: NonZeroUsize,
     min_level_size: NonZeroUsize,
+    _update_id: u64,
 }
 
 impl<'t, 'u, 'i> Facets<'t, 'u, 'i> {
-    pub fn new(wtxn: &'t mut heed::RwTxn<'i, 'u>, index: &'i Index) -> Facets<'t, 'u, 'i> {
+    pub fn new(
+        wtxn: &'t mut heed::RwTxn<'i, 'u>,
+        index: &'i Index,
+        update_id: u64,
+    ) -> Facets<'t, 'u, 'i> {
         Facets {
             wtxn,
             index,
@@ -36,6 +41,7 @@ impl<'t, 'u, 'i> Facets<'t, 'u, 'i> {
             chunk_fusing_shrink_size: None,
             level_group_size: NonZeroUsize::new(4).unwrap(),
             min_level_size: NonZeroUsize::new(5).unwrap(),
+            _update_id: update_id,
         }
     }
 
diff --git a/src/update/index_documents/mod.rs b/src/update/index_documents/mod.rs
index 90bc5ef3d..e38c640a0 100644
--- a/src/update/index_documents/mod.rs
+++ b/src/update/index_documents/mod.rs
@@ -12,8 +12,9 @@ use grenad::{Writer, Sorter, Merger, Reader, FileFuse, CompressionType};
 use heed::types::ByteSlice;
 use log::{debug, info, error};
 use memmap::Mmap;
-use rayon::prelude::*;
 use rayon::ThreadPool;
+use rayon::prelude::*;
+use serde::{Serialize, Deserialize};
 
 use crate::index::Index;
 use crate::update::{Facets, UpdateIndexingStep};
@@ -32,6 +33,11 @@ mod merge_function;
 mod store;
 mod transform;
 
+#[derive(Debug, Serialize, Deserialize, Clone)]
+pub struct DocumentAdditionResult {
+    nb_documents: usize,
+}
+
 #[derive(Debug, Copy, Clone)]
 pub enum WriteMethod {
     Append,
@@ -175,7 +181,7 @@ pub fn write_into_lmdb_database(
     Ok(())
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
 #[non_exhaustive]
 pub enum IndexDocumentsMethod {
     /// Replace the previous document with the new one,
@@ -187,7 +193,7 @@ pub enum IndexDocumentsMethod {
     UpdateDocuments,
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
 #[non_exhaustive]
 pub enum UpdateFormat {
     /// The given update is a real **comma seperated** CSV with headers on the first line.
@@ -214,10 +220,15 @@ pub struct IndexDocuments<'t, 'u, 'i, 'a> {
     update_method: IndexDocumentsMethod,
     update_format: UpdateFormat,
     autogenerate_docids: bool,
+    update_id: u64,
 }
 
 impl<'t, 'u, 'i, 'a> IndexDocuments<'t, 'u, 'i, 'a> {
-    pub fn new(wtxn: &'t mut heed::RwTxn<'i, 'u>, index: &'i Index) -> IndexDocuments<'t, 'u, 'i, 'a> {
+    pub fn new(
+        wtxn: &'t mut heed::RwTxn<'i, 'u>,
+        index: &'i Index,
+        update_id: u64,
+    ) -> IndexDocuments<'t, 'u, 'i, 'a> {
         IndexDocuments {
             wtxn,
             index,
@@ -234,6 +245,7 @@ impl<'t, 'u, 'i, 'a> IndexDocuments<'t, 'u, 'i, 'a> {
             update_method: IndexDocumentsMethod::ReplaceDocuments,
             update_format: UpdateFormat::Json,
             autogenerate_docids: true,
+            update_id,
         }
     }
 
@@ -253,12 +265,14 @@ impl<'t, 'u, 'i, 'a> IndexDocuments<'t, 'u, 'i, 'a> {
         self.autogenerate_docids = false;
     }
 
-    pub fn execute<R, F>(self, reader: R, progress_callback: F) -> anyhow::Result<()>
+    pub fn execute<R, F>(self, reader: R, progress_callback: F) -> anyhow::Result<DocumentAdditionResult>
     where
         R: io::Read,
-        F: Fn(UpdateIndexingStep) + Sync,
+        F: Fn(UpdateIndexingStep, u64) + Sync,
     {
         let before_transform = Instant::now();
+        let update_id = self.update_id;
+        let progress_callback = |step| progress_callback(step, update_id);
 
         let transform = Transform {
             rtxn: &self.wtxn,
@@ -279,9 +293,12 @@ impl<'t, 'u, 'i, 'a> IndexDocuments<'t, 'u, 'i, 'a> {
             UpdateFormat::JsonStream => transform.output_from_json_stream(reader, &progress_callback)?,
         };
 
+        let nb_documents = output.documents_count;
+
         info!("Update transformed in {:.02?}", before_transform.elapsed());
 
-        self.execute_raw(output, progress_callback)
+        self.execute_raw(output, progress_callback)?;
+        Ok(DocumentAdditionResult { nb_documents })
     }
 
     pub fn execute_raw<F>(self, output: TransformOutput, progress_callback: F) -> anyhow::Result<()>
@@ -312,6 +329,7 @@ impl<'t, 'u, 'i, 'a> IndexDocuments<'t, 'u, 'i, 'a> {
                 chunk_compression_level: self.chunk_compression_level,
                 chunk_fusing_shrink_size: self.chunk_fusing_shrink_size,
                 thread_pool: self.thread_pool,
+                update_id: self.update_id,
             };
             let mut deletion_builder = update_builder.delete_documents(self.wtxn, self.index)?;
             debug!("documents to delete {:?}", replaced_documents_ids);
@@ -607,7 +625,7 @@ impl<'t, 'u, 'i, 'a> IndexDocuments<'t, 'u, 'i, 'a> {
             });
         }
 
-        let mut builder = Facets::new(self.wtxn, self.index);
+        let mut builder = Facets::new(self.wtxn, self.index, self.update_id);
         builder.chunk_compression_type = self.chunk_compression_type;
         builder.chunk_compression_level = self.chunk_compression_level;
         builder.chunk_fusing_shrink_size = self.chunk_fusing_shrink_size;
@@ -642,9 +660,9 @@ mod tests {
         // First we send 3 documents with ids from 1 to 3.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"id,name\n1,kevin\n2,kevina\n3,benoit\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is 3 documents now.
@@ -656,9 +674,9 @@ mod tests {
         // Second we send 1 document with id 1, to erase the previous ones.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"id,name\n1,updated kevin\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 1);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is **always** 3 documents.
@@ -670,9 +688,9 @@ mod tests {
         // Third we send 3 documents again to replace the existing ones.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"id,name\n1,updated second kevin\n2,updated kevina\n3,updated benoit\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 2);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is **always** 3 documents.
@@ -693,10 +711,10 @@ mod tests {
         // change the index method to merge documents.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"id,name\n1,kevin\n1,kevina\n1,benoit\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.update_format(UpdateFormat::Csv);
         builder.index_documents_method(IndexDocumentsMethod::UpdateDocuments);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is only 1 document now.
@@ -720,10 +738,10 @@ mod tests {
         // Second we send 1 document with id 1, to force it to be merged with the previous one.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"id,age\n1,25\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 1);
         builder.update_format(UpdateFormat::Csv);
         builder.index_documents_method(IndexDocumentsMethod::UpdateDocuments);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is **always** 1 document.
@@ -756,10 +774,10 @@ mod tests {
         // First we send 3 documents with ids from 1 to 3.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"name\nkevin\nkevina\nbenoit\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.disable_autogenerate_docids();
         builder.update_format(UpdateFormat::Csv);
-        assert!(builder.execute(content, |_| ()).is_err());
+        assert!(builder.execute(content, |_, _| ()).is_err());
         wtxn.commit().unwrap();
 
         // Check that there is no document.
@@ -783,10 +801,10 @@ mod tests {
             { "name": "kevin" },
             { "name": "benoit" }
         ]"#[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.disable_autogenerate_docids();
         builder.update_format(UpdateFormat::Json);
-        assert!(builder.execute(content, |_| ()).is_err());
+        assert!(builder.execute(content, |_, _| ()).is_err());
         wtxn.commit().unwrap();
 
         // Check that there is no document.
@@ -806,9 +824,9 @@ mod tests {
         // First we send 3 documents with ids from 1 to 3.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"name\nkevin\nkevina\nbenoit\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is 3 documents now.
@@ -824,9 +842,9 @@ mod tests {
         // Second we send 1 document with the generated uuid, to erase the previous ones.
         let mut wtxn = index.write_txn().unwrap();
         let content = format!("id,name\n{},updated kevin", kevin_uuid);
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 1);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content.as_bytes(), |_| ()).unwrap();
+        builder.execute(content.as_bytes(), |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is **always** 3 documents.
@@ -859,9 +877,9 @@ mod tests {
         // First we send 3 documents with ids from 1 to 3.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"id,name\n1,kevin\n2,kevina\n3,benoit\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is 3 documents now.
@@ -873,9 +891,9 @@ mod tests {
         // Second we send 1 document without specifying the id.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"name\nnew kevin"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 1);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is 4 documents now.
@@ -895,9 +913,9 @@ mod tests {
         // First we send 0 documents and only headers.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"id,name\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is no documents.
@@ -921,9 +939,9 @@ mod tests {
             { "name": "kevina", "id": 21 },
             { "name": "benoit" }
         ]"#[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.update_format(UpdateFormat::Json);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is 3 documents now.
@@ -943,9 +961,9 @@ mod tests {
         // First we send 0 documents.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"[]"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.update_format(UpdateFormat::Json);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is no documents.
@@ -969,9 +987,9 @@ mod tests {
         { "name": "kevina", "id": 21 }
         { "name": "benoit" }
         "#[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.update_format(UpdateFormat::JsonStream);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is 3 documents now.
@@ -992,18 +1010,18 @@ mod tests {
         let mut wtxn = index.write_txn().unwrap();
         // There is a space in the document id.
         let content = &b"id,name\nbrume bleue,kevin\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.update_format(UpdateFormat::Csv);
-        assert!(builder.execute(content, |_| ()).is_err());
+        assert!(builder.execute(content, |_, _| ()).is_err());
         wtxn.commit().unwrap();
 
         // First we send 1 document with a valid id.
         let mut wtxn = index.write_txn().unwrap();
         // There is a space in the document id.
         let content = &b"id,name\n32,kevin\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 1);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is 1 document now.
@@ -1027,9 +1045,9 @@ mod tests {
             { "id": 1, "name": "kevina", "array": ["I", "am", "fine"] },
             { "id": 2, "name": "benoit", "array_of_object": [{ "wow": "amazing" }] }
         ]"#[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.update_format(UpdateFormat::Json);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that there is 1 documents now.
diff --git a/src/update/mod.rs b/src/update/mod.rs
index 407d9f498..2cd532c83 100644
--- a/src/update/mod.rs
+++ b/src/update/mod.rs
@@ -10,7 +10,7 @@ mod update_step;
 pub use self::available_documents_ids::AvailableDocumentsIds;
 pub use self::clear_documents::ClearDocuments;
 pub use self::delete_documents::DeleteDocuments;
-pub use self::index_documents::{IndexDocuments, IndexDocumentsMethod, UpdateFormat};
+pub use self::index_documents::{IndexDocuments, IndexDocumentsMethod, UpdateFormat, DocumentAdditionResult};
 pub use self::facets::Facets;
 pub use self::settings::Settings;
 pub use self::update_builder::UpdateBuilder;
diff --git a/src/update/settings.rs b/src/update/settings.rs
index dbe951761..17a9da1eb 100644
--- a/src/update/settings.rs
+++ b/src/update/settings.rs
@@ -23,6 +23,7 @@ pub struct Settings<'a, 't, 'u, 'i> {
     pub(crate) chunk_compression_level: Option<u32>,
     pub(crate) chunk_fusing_shrink_size: Option<u64>,
     pub(crate) thread_pool: Option<&'a ThreadPool>,
+    update_id: u64,
 
     // If a struct field is set to `None` it means that it hasn't been set by the user,
     // however if it is `Some(None)` it means that the user forced a reset of the setting.
@@ -33,7 +34,11 @@ pub struct Settings<'a, 't, 'u, 'i> {
 }
 
 impl<'a, 't, 'u, 'i> Settings<'a, 't, 'u, 'i> {
-    pub fn new(wtxn: &'t mut heed::RwTxn<'i, 'u>, index: &'i Index) -> Settings<'a, 't, 'u, 'i> {
+    pub fn new(
+        wtxn: &'t mut heed::RwTxn<'i, 'u>,
+        index: &'i Index,
+        update_id: u64,
+    ) -> Settings<'a, 't, 'u, 'i> {
         Settings {
             wtxn,
             index,
@@ -49,6 +54,7 @@ impl<'a, 't, 'u, 'i> Settings<'a, 't, 'u, 'i> {
             displayed_fields: None,
             faceted_fields: None,
             criteria: None,
+            update_id,
         }
     }
 
@@ -86,9 +92,11 @@ impl<'a, 't, 'u, 'i> Settings<'a, 't, 'u, 'i> {
 
     fn reindex<F>(&mut self, cb: &F, old_fields_ids_map: FieldsIdsMap) -> anyhow::Result<()>
     where
-        F: Fn(UpdateIndexingStep) + Sync,
+        F: Fn(UpdateIndexingStep, u64) + Sync
     {
         let fields_ids_map = self.index.fields_ids_map(self.wtxn)?;
+        let update_id = self.update_id;
+        let cb = |step| cb(step, update_id);
         // if the settings are set before any document update, we don't need to do anything, and
         // will set the primary key during the first document addition.
         if self.index.number_of_documents(&self.wtxn)? == 0 {
@@ -118,11 +126,11 @@ impl<'a, 't, 'u, 'i> Settings<'a, 't, 'u, 'i> {
             fields_ids_map.clone())?;
 
         // We clear the full database (words-fst, documents ids and documents content).
-        ClearDocuments::new(self.wtxn, self.index).execute()?;
+        ClearDocuments::new(self.wtxn, self.index, self.update_id).execute()?;
 
         // We index the generated `TransformOutput` which must contain
         // all the documents with fields in the newly defined searchable order.
-        let mut indexing_builder = IndexDocuments::new(self.wtxn, self.index);
+        let mut indexing_builder = IndexDocuments::new(self.wtxn, self.index, self.update_id);
         indexing_builder.log_every_n = self.log_every_n;
         indexing_builder.max_nb_chunks = self.max_nb_chunks;
         indexing_builder.max_memory = self.max_memory;
@@ -239,7 +247,7 @@ impl<'a, 't, 'u, 'i> Settings<'a, 't, 'u, 'i> {
 
     pub fn execute<F>(mut self, progress_callback: F) -> anyhow::Result<()>
     where
-        F: Fn(UpdateIndexingStep) + Sync
+        F: Fn(UpdateIndexingStep, u64) + Sync
         {
             let old_fields_ids_map = self.index.fields_ids_map(&self.wtxn)?;
             self.update_displayed()?;
@@ -276,16 +284,16 @@ mod tests {
         // First we send 3 documents with ids from 1 to 3.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"name,age\nkevin,23\nkevina,21\nbenoit,34\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // We change the searchable fields to be the "name" field only.
         let mut wtxn = index.write_txn().unwrap();
-        let mut builder = Settings::new(&mut wtxn, &index);
+        let mut builder = Settings::new(&mut wtxn, &index, 1);
         builder.set_searchable_fields(vec!["name".into()]);
-        builder.execute(|_| ()).unwrap();
+        builder.execute(|_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that the searchable field is correctly set to "name" only.
@@ -305,9 +313,9 @@ mod tests {
 
         // We change the searchable fields to be the "name" field only.
         let mut wtxn = index.write_txn().unwrap();
-        let mut builder = Settings::new(&mut wtxn, &index);
+        let mut builder = Settings::new(&mut wtxn, &index, 2);
         builder.reset_searchable_fields();
-        builder.execute(|_| ()).unwrap();
+        builder.execute(|_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that the searchable field have been reset and documents are found now.
@@ -331,18 +339,18 @@ mod tests {
         // First we send 3 documents with ids from 1 to 3.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"name,age\nkevin,23\nkevina,21\nbenoit,34\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // In the same transaction we change the displayed fields to be only the "age".
         // We also change the searchable fields to be the "name" field only.
         let mut wtxn = index.write_txn().unwrap();
-        let mut builder = Settings::new(&mut wtxn, &index);
+        let mut builder = Settings::new(&mut wtxn, &index, 1);
         builder.set_displayed_fields(vec!["age".into()]);
         builder.set_searchable_fields(vec!["name".into()]);
-        builder.execute(|_| ()).unwrap();
+        builder.execute(|_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that the displayed fields are correctly set to `None` (default value).
@@ -353,9 +361,9 @@ mod tests {
 
         // We change the searchable fields to be the "name" field only.
         let mut wtxn = index.write_txn().unwrap();
-        let mut builder = Settings::new(&mut wtxn, &index);
+        let mut builder = Settings::new(&mut wtxn, &index, 2);
         builder.reset_searchable_fields();
-        builder.execute(|_| ()).unwrap();
+        builder.execute(|_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that the displayed fields always contains only the "age" field.
@@ -375,9 +383,9 @@ mod tests {
         // First we send 3 documents with ids from 1 to 3.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"name,age\nkevin,23\nkevina,21\nbenoit,34\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that the displayed fields are correctly set to `None` (default value).
@@ -397,14 +405,14 @@ mod tests {
         // First we send 3 documents with ids from 1 to 3.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"name,age\nkevin,23\nkevina,21\nbenoit,34\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 0);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
 
         // In the same transaction we change the displayed fields to be only the age.
-        let mut builder = Settings::new(&mut wtxn, &index);
+        let mut builder = Settings::new(&mut wtxn, &index, 0);
         builder.set_displayed_fields(vec!["age".into()]);
-        builder.execute(|_| ()).unwrap();
+        builder.execute(|_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that the displayed fields are correctly set to only the "age" field.
@@ -415,9 +423,9 @@ mod tests {
 
         // We reset the fields ids to become `None`, the default value.
         let mut wtxn = index.write_txn().unwrap();
-        let mut builder = Settings::new(&mut wtxn, &index);
+        let mut builder = Settings::new(&mut wtxn, &index, 0);
         builder.reset_displayed_fields();
-        builder.execute(|_| ()).unwrap();
+        builder.execute(|_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that the displayed fields are correctly set to `None` (default value).
@@ -436,15 +444,15 @@ mod tests {
 
         // Set the faceted fields to be the age.
         let mut wtxn = index.write_txn().unwrap();
-        let mut builder = Settings::new(&mut wtxn, &index);
+        let mut builder = Settings::new(&mut wtxn, &index, 0);
         builder.set_faceted_fields(hashmap!{ "age".into() => "integer".into() });
-        builder.execute(|_| ()).unwrap();
+        builder.execute(|_, _| ()).unwrap();
 
         // Then index some documents.
         let content = &b"name,age\nkevin,23\nkevina,21\nbenoit,34\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 1);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // Check that the displayed fields are correctly set.
@@ -459,9 +467,9 @@ mod tests {
         // Index a little more documents with new and current facets values.
         let mut wtxn = index.write_txn().unwrap();
         let content = &b"name,age\nkevin2,23\nkevina2,21\nbenoit2,35\n"[..];
-        let mut builder = IndexDocuments::new(&mut wtxn, &index);
+        let mut builder = IndexDocuments::new(&mut wtxn, &index, 2);
         builder.update_format(UpdateFormat::Csv);
-        builder.execute(content, |_| ()).unwrap();
+        builder.execute(content, |_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         let rtxn = index.read_txn().unwrap();
@@ -480,14 +488,14 @@ mod tests {
 
         // Set all the settings except searchable
         let mut wtxn = index.write_txn().unwrap();
-        let mut builder = Settings::new(&mut wtxn, &index);
+        let mut builder = Settings::new(&mut wtxn, &index, 0);
         builder.set_displayed_fields(vec!["hello".to_string()]);
         builder.set_faceted_fields(hashmap!{
             "age".into() => "integer".into(),
             "toto".into() => "integer".into(),
         });
         builder.set_criteria(vec!["asc(toto)".to_string()]);
-        builder.execute(|_| ()).unwrap();
+        builder.execute(|_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         // check the output
@@ -500,9 +508,9 @@ mod tests {
 
         // We set toto and age as searchable to force reordering of the fields
         let mut wtxn = index.write_txn().unwrap();
-        let mut builder = Settings::new(&mut wtxn, &index);
+        let mut builder = Settings::new(&mut wtxn, &index, 1);
         builder.set_searchable_fields(vec!["toto".to_string(), "age".to_string()]);
-        builder.execute(|_| ()).unwrap();
+        builder.execute(|_, _| ()).unwrap();
         wtxn.commit().unwrap();
 
         let rtxn = index.read_txn().unwrap();
diff --git a/src/update/update_builder.rs b/src/update/update_builder.rs
index 43e3c28ed..8d6eb034d 100644
--- a/src/update/update_builder.rs
+++ b/src/update/update_builder.rs
@@ -13,10 +13,11 @@ pub struct UpdateBuilder<'a> {
     pub(crate) chunk_compression_level: Option<u32>,
     pub(crate) chunk_fusing_shrink_size: Option<u64>,
     pub(crate) thread_pool: Option<&'a ThreadPool>,
+    pub(crate) update_id: u64,
 }
 
 impl<'a> UpdateBuilder<'a> {
-    pub fn new() -> UpdateBuilder<'a> {
+    pub fn new(update_id: u64) -> UpdateBuilder<'a> {
         UpdateBuilder {
             log_every_n: None,
             max_nb_chunks: None,
@@ -26,6 +27,7 @@ impl<'a> UpdateBuilder<'a> {
             chunk_compression_level: None,
             chunk_fusing_shrink_size: None,
             thread_pool: None,
+            update_id,
         }
     }
 
@@ -67,7 +69,7 @@ impl<'a> UpdateBuilder<'a> {
         index: &'i Index,
     ) -> ClearDocuments<'t, 'u, 'i>
     {
-        ClearDocuments::new(wtxn, index)
+        ClearDocuments::new(wtxn, index, self.update_id)
     }
 
     pub fn delete_documents<'t, 'u, 'i>(
@@ -76,7 +78,7 @@ impl<'a> UpdateBuilder<'a> {
         index: &'i Index,
     ) -> anyhow::Result<DeleteDocuments<'t, 'u, 'i>>
     {
-        DeleteDocuments::new(wtxn, index)
+        DeleteDocuments::new(wtxn, index, self.update_id)
     }
 
     pub fn index_documents<'t, 'u, 'i>(
@@ -85,7 +87,7 @@ impl<'a> UpdateBuilder<'a> {
         index: &'i Index,
     ) -> IndexDocuments<'t, 'u, 'i, 'a>
     {
-        let mut builder = IndexDocuments::new(wtxn, index);
+        let mut builder = IndexDocuments::new(wtxn, index, self.update_id);
 
         builder.log_every_n = self.log_every_n;
         builder.max_nb_chunks = self.max_nb_chunks;
@@ -105,7 +107,7 @@ impl<'a> UpdateBuilder<'a> {
         index: &'i Index,
     ) -> Settings<'a, 't, 'u, 'i>
     {
-        let mut builder = Settings::new(wtxn, index);
+        let mut builder = Settings::new(wtxn, index, self.update_id);
 
         builder.log_every_n = self.log_every_n;
         builder.max_nb_chunks = self.max_nb_chunks;
@@ -125,7 +127,7 @@ impl<'a> UpdateBuilder<'a> {
         index: &'i Index,
     ) -> Facets<'t, 'u, 'i>
     {
-        let mut builder = Facets::new(wtxn, index);
+        let mut builder = Facets::new(wtxn, index, self.update_id);
 
         builder.chunk_compression_type = self.chunk_compression_type;
         builder.chunk_compression_level = self.chunk_compression_level;
@@ -134,9 +136,3 @@ impl<'a> UpdateBuilder<'a> {
         builder
     }
 }
-
-impl Default for UpdateBuilder<'_> {
-    fn default() -> Self {
-        Self::new()
-    }
-}