diff --git a/Cargo.lock b/Cargo.lock
index dda43d5..d383bf7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1482,6 +1482,7 @@ dependencies = [
  "chrono",
  "config",
  "futures",
+ "hex",
  "http",
  "http-body-util",
  "miroir-core",
@@ -1491,6 +1492,7 @@ dependencies = [
  "serde",
  "serde_json",
  "serde_qs",
+ "sha2",
  "tokio",
  "tower",
  "tracing",
diff --git a/crates/miroir-proxy/Cargo.toml b/crates/miroir-proxy/Cargo.toml
index 80a6fed..5857616 100644
--- a/crates/miroir-proxy/Cargo.toml
+++ b/crates/miroir-proxy/Cargo.toml
@@ -27,6 +27,8 @@ prometheus = { version = "0.13", features = ["process"] }
 once_cell = "1.20"
 futures = "0.3"
 miroir-core = { path = "../miroir-core" }
+sha2 = "0.10"
+hex = "0.4"
 
 [dev-dependencies]
 tower = "0.5"
diff --git a/crates/miroir-proxy/src/routes/documents.rs b/crates/miroir-proxy/src/routes/documents.rs
index 2981d27..15993ec 100644
--- a/crates/miroir-proxy/src/routes/documents.rs
+++ b/crates/miroir-proxy/src/routes/documents.rs
@@ -48,7 +48,7 @@ async fn add_documents(
 
     // Get primary key for the index (for now, assume it's in the document or use default)
     // In production, we'd query the index settings to get the primary key field
-    let primary_key = get_primary_key(&body, &headers).unwrap_or("id");
+    let primary_key = get_primary_key(&body, &headers).unwrap_or_else(|| "id".to_string());
 
     // Inject _miroir_shard into each document and group by shard
     let mut docs_by_shard: std::collections::HashMap<u32, Vec<Value>> = std::collections::HashMap::new();
@@ -119,7 +119,9 @@ async fn add_documents(
 
         // Merge responses
         for resp in result.responses {
-            all_responses.push(resp.body);
+            if let Ok(json) = serde_json::from_slice::<Value>(&resp.body) {
+                all_responses.push(json);
+            }
         }
     }
 
@@ -377,8 +379,9 @@ async fn get_document(
 
     let resp = &result.responses[0];
 
-    // Strip _miroir_shard from response
-    let mut body = resp.body.clone();
+    // Parse response body as JSON and strip _miroir_shard
+    let mut body: Value = serde_json::from_slice(&resp.body)
+        .unwrap_or_else(|_| serde_json::json!({}));
     if let Some(obj) = body.as_object_mut() {
         obj.remove("_miroir_shard");
     }
diff --git a/crates/miroir-proxy/src/routes/indexes.rs b/crates/miroir-proxy/src/routes/indexes.rs
index fd14046..fd4913e 100644
--- a/crates/miroir-proxy/src/routes/indexes.rs
+++ b/crates/miroir-proxy/src/routes/indexes.rs
@@ -92,9 +92,11 @@ async fn list_indexes(
                 .map_err(|e| ErrorResponse::internal_error(e.to_string()))?;
 
             if let Some(resp) = result.responses.first() {
-                if let Some(arr) = resp.body.get("results").and_then(|r| r.as_array()) {
-                    // Return results from first successful group
-                    return Ok(Json(serde_json::json!({ "results": arr })));
+                if let Ok(json) = serde_json::from_slice::<Value>(&resp.body) {
+                    if let Some(arr) = json.get("results").and_then(|r| r.as_array()) {
+                        // Return results from first successful group
+                        return Ok(Json(serde_json::json!({ "results": arr })));
+                    }
                 }
             }
         }
@@ -164,8 +166,10 @@ async fn create_index(
 
     // After index creation, we need to update settings to inject _miroir_shard
     // This is done in a follow-up request
+    let body: Value = serde_json::from_slice(&resp.body)
+        .unwrap_or_else(|_| serde_json::json!({}));
 
-    Ok((status, Json(resp.body.clone())).into_response())
+    Ok((status, Json(body)).into_response())
 }
 
 /// GET /indexes/:index - Get index metadata.
@@ -196,7 +200,9 @@ async fn get_index(
             if let Some(resp) = result.responses.first() {
                 let status = resp.status;
                 if status == 200 {
-                    return Ok(Json(resp.body.clone()));
+                    if let Ok(json) = serde_json::from_slice::<Value>(&resp.body) {
+                        return Ok(Json(json));
+                    }
                 } else if status == 404 {
                     return Err(ErrorResponse::index_not_found(&index));
                 }