diff --git a/src/subcommand/serve.rs b/src/subcommand/serve.rs
index 6da45f8b2..9b2a17ed0 100644
--- a/src/subcommand/serve.rs
+++ b/src/subcommand/serve.rs
@@ -23,7 +23,7 @@ use warp::filters::ws::Message;
 use warp::{Filter, http::Response};
 
 use crate::tokenizer::{simple_tokenizer, TokenType};
-use crate::update::{UpdateBuilder, IndexDocumentsMethod};
+use crate::update::{UpdateBuilder, IndexDocumentsMethod, UpdateFormat};
 use crate::{Index, UpdateStore, SearchResult};
 
 #[derive(Debug, StructOpt)]
@@ -157,7 +157,7 @@ enum UpdateStatus<M, P, N> {
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(tag = "type")]
 enum UpdateMeta {
-    DocumentsAddition,
+    DocumentsAddition { method: String, format: String },
     ClearDocuments,
 }
 
@@ -218,17 +218,22 @@ pub fn run(opt: Opt) -> anyhow::Result<()> {
 
             // we extract the update type and execute the update itself.
             let result: anyhow::Result<()> = match meta {
-                UpdateMeta::DocumentsAddition => {
+                UpdateMeta::DocumentsAddition { method, format } => {
                     // We must use the write transaction of the update here.
                     let mut wtxn = index_cloned.write_txn()?;
                     let mut builder = update_builder.index_documents(&mut wtxn, &index_cloned);
 
-                    let replace_documents = true;
-                    if replace_documents {
-                        builder.index_documents_method(IndexDocumentsMethod::ReplaceDocuments);
-                    } else {
-                        builder.index_documents_method(IndexDocumentsMethod::UpdateDocuments);
-                    }
+                    match format.as_str() {
+                        "json" => builder.update_format(UpdateFormat::Json),
+                        "csv" => builder.update_format(UpdateFormat::Csv),
+                        otherwise => panic!("invalid update format {:?}", otherwise),
+                    };
+
+                    match method.as_str() {
+                        "replace" => builder.index_documents_method(IndexDocumentsMethod::ReplaceDocuments),
+                        "update" => builder.index_documents_method(IndexDocumentsMethod::UpdateDocuments),
+                        otherwise => panic!("invalid indexing method {:?}", otherwise),
+                    };
 
                     let gzipped = false;
                     let reader = if gzipped {
@@ -461,6 +466,8 @@ pub fn run(opt: Opt) -> anyhow::Result<()> {
     async fn buf_stream(
         update_store: Arc<UpdateStore<UpdateMeta, String>>,
         update_status_sender: broadcast::Sender<UpdateStatus<UpdateMeta, UpdateMetaProgress, String>>,
+        update_method: Option<String>,
+        update_format: UpdateFormat,
         mut stream: impl futures::Stream<Item=Result<impl bytes::Buf, warp::Error>> + Unpin,
     ) -> Result<impl warp::Reply, warp::Rejection>
     {
@@ -475,7 +482,18 @@ pub fn run(opt: Opt) -> anyhow::Result<()> {
         let file = file.into_std().await;
         let mmap = unsafe { memmap::Mmap::map(&file).unwrap() };
 
-        let meta = UpdateMeta::DocumentsAddition;
+        let method = match update_method.as_deref() {
+            Some("replace") => String::from("replace"),
+            Some("update") => String::from("update"),
+            _ => String::from("replace"),
+        };
+
+        let format = match update_format {
+            UpdateFormat::Csv => String::from("csv"),
+            UpdateFormat::Json => String::from("json"),
+        };
+
+        let meta = UpdateMeta::DocumentsAddition { method, format };
         let update_id = update_store.register_update(&meta, &mmap[..]).unwrap();
         let _ = update_status_sender.send(UpdateStatus::Pending { update_id, meta });
         eprintln!("update {} registered", update_id);
@@ -483,14 +501,43 @@ pub fn run(opt: Opt) -> anyhow::Result<()> {
         Ok(warp::reply())
     }
 
+    #[derive(Deserialize)]
+    struct QueryUpdate {
+        method: Option<String>,
+    }
+
     let update_store_cloned = update_store.clone();
     let update_status_sender_cloned = update_status_sender.clone();
     let indexing_route_csv = warp::filters::method::post()
         .and(warp::path!("documents"))
         .and(warp::header::exact_ignore_case("content-type", "text/csv"))
+        .and(warp::filters::query::query())
         .and(warp::body::stream())
-        .and_then(move |stream| {
-            buf_stream(update_store_cloned.clone(), update_status_sender_cloned.clone(), stream)
+        .and_then(move |params: QueryUpdate, stream| {
+            buf_stream(
+                update_store_cloned.clone(),
+                update_status_sender_cloned.clone(),
+                params.method,
+                UpdateFormat::Csv,
+                stream,
+            )
+        });
+
+    let update_store_cloned = update_store.clone();
+    let update_status_sender_cloned = update_status_sender.clone();
+    let indexing_route_json = warp::filters::method::post()
+        .and(warp::path!("documents"))
+        .and(warp::header::exact_ignore_case("content-type", "application/json"))
+        .and(warp::filters::query::query())
+        .and(warp::body::stream())
+        .and_then(move |params: QueryUpdate, stream| {
+            buf_stream(
+                update_store_cloned.clone(),
+                update_status_sender_cloned.clone(),
+                params.method,
+                UpdateFormat::Json,
+                stream,
+            )
         });
 
     let update_status_sender_cloned = update_status_sender.clone();
@@ -547,6 +594,7 @@ pub fn run(opt: Opt) -> anyhow::Result<()> {
         .or(dash_logo_black_route)
         .or(query_route)
         .or(indexing_route_csv)
+        .or(indexing_route_json)
         .or(clearing_route)
         .or(update_ws_route);
 
diff --git a/src/update/mod.rs b/src/update/mod.rs
index fcaffe9c0..949724bcd 100644
--- a/src/update/mod.rs
+++ b/src/update/mod.rs
@@ -8,6 +8,6 @@ mod update_store;
 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};
+pub use self::index_documents::{IndexDocuments, IndexDocumentsMethod, UpdateFormat};
 pub use self::update_builder::UpdateBuilder;
 pub use self::update_store::UpdateStore;