[router] conversation item API: create, retrieve and delete (#11369)

sgl-router/src/data_connector/conversation_item_memory_store.rs

@@ -142,6 +142,50 @@ impl ConversationItemStorage for MemoryConversationItemStorage {
 
         Ok(results)
     }
+
+    async fn get_item(&self, item_id: &ConversationItemId) -> Result<Option<ConversationItem>> {
+        let items = self.items.read().unwrap();
+        Ok(items.get(item_id).cloned())
+    }
+
+    async fn is_item_linked(
+        &self,
+        conversation_id: &ConversationId,
+        item_id: &ConversationItemId,
+    ) -> Result<bool> {
+        let rev = self.rev_index.read().unwrap();
+        if let Some(conv_idx) = rev.get(conversation_id) {
+            Ok(conv_idx.contains_key(&item_id.0))
+        } else {
+            Ok(false)
+        }
+    }
+
+    async fn delete_item(
+        &self,
+        conversation_id: &ConversationId,
+        item_id: &ConversationItemId,
+    ) -> Result<()> {
+        // Get the key from rev_index and remove the entry at the same time
+        let key_to_remove = {
+            let mut rev = self.rev_index.write().unwrap();
+            if let Some(conv_idx) = rev.get_mut(conversation_id) {
+                conv_idx.remove(&item_id.0)
+            } else {
+                None
+            }
+        };
+
+        // If the item was in rev_index, remove it from links as well
+        if let Some(key) = key_to_remove {
+            let mut links = self.links.write().unwrap();
+            if let Some(conv_links) = links.get_mut(conversation_id) {
+                conv_links.remove(&key);
+            }
+        }
+
+        Ok(())
+    }
 }
 
 #[cfg(test)]

sgl-router/src/data_connector/conversation_item_oracle_store.rs

@@ -243,6 +243,92 @@ impl ConversationItemStorage for OracleConversationItemStorage {
             )
             .collect()
     }
+
+    async fn get_item(&self, item_id: &ConversationItemId) -> ItemResult<Option<ConversationItem>> {
+        let iid = item_id.0.clone();
+
+        self.with_connection(move |conn| {
+            let mut stmt = conn
+                .statement(
+                    "SELECT id, response_id, item_type, role, content, status, created_at \
+                     FROM conversation_items WHERE id = :1",
+                )
+                .build()
+                .map_err(map_oracle_error)?;
+
+            let mut rows = stmt.query(&[&iid]).map_err(map_oracle_error)?;
+
+            if let Some(row_res) = rows.next() {
+                let row = row_res.map_err(map_oracle_error)?;
+                let id: String = row.get(0).map_err(map_oracle_error)?;
+                let response_id: Option<String> = row.get(1).map_err(map_oracle_error)?;
+                let item_type: String = row.get(2).map_err(map_oracle_error)?;
+                let role: Option<String> = row.get(3).map_err(map_oracle_error)?;
+                let content_raw: Option<String> = row.get(4).map_err(map_oracle_error)?;
+                let status: Option<String> = row.get(5).map_err(map_oracle_error)?;
+                let created_at: DateTime<Utc> = row.get(6).map_err(map_oracle_error)?;
+
+                let content = match content_raw {
+                    Some(s) => serde_json::from_str(&s)?,
+                    None => Value::Null,
+                };
+
+                Ok(Some(ConversationItem {
+                    id: ConversationItemId(id),
+                    response_id,
+                    item_type,
+                    role,
+                    content,
+                    status,
+                    created_at,
+                }))
+            } else {
+                Ok(None)
+            }
+        })
+        .await
+    }
+
+    async fn is_item_linked(
+        &self,
+        conversation_id: &ConversationId,
+        item_id: &ConversationItemId,
+    ) -> ItemResult<bool> {
+        let cid = conversation_id.0.clone();
+        let iid = item_id.0.clone();
+
+        self.with_connection(move |conn| {
+            let count: i64 = conn
+                .query_row_as(
+                    "SELECT COUNT(*) FROM conversation_item_links WHERE conversation_id = :1 AND item_id = :2",
+                    &[&cid, &iid],
+                )
+                .map_err(map_oracle_error)?;
+            Ok(count > 0)
+        })
+        .await
+    }
+
+    async fn delete_item(
+        &self,
+        conversation_id: &ConversationId,
+        item_id: &ConversationItemId,
+    ) -> ItemResult<()> {
+        let cid = conversation_id.0.clone();
+        let iid = item_id.0.clone();
+
+        self.with_connection(move |conn| {
+            // Delete ONLY the link (do not delete the item itself)
+            conn.execute(
+                "DELETE FROM conversation_item_links WHERE conversation_id = :1 AND item_id = :2",
+                &[&cid, &iid],
+            )
+            .map_err(map_oracle_error)?;
+
+            Ok(())
+        })
+        .await
+    }
 }
 
 #[derive(Clone)]

sgl-router/src/data_connector/conversation_items.rs

@@ -94,15 +94,32 @@ pub trait ConversationItemStorage: Send + Sync + 'static {
         conversation_id: &ConversationId,
         params: ListParams,
     ) -> Result<Vec<ConversationItem>>;
+
+    /// Get a single item by ID
+    async fn get_item(&self, item_id: &ConversationItemId) -> Result<Option<ConversationItem>>;
+
+    /// Check if an item is linked to a conversation
+    async fn is_item_linked(
+        &self,
+        conversation_id: &ConversationId,
+        item_id: &ConversationItemId,
+    ) -> Result<bool>;
+
+    /// Delete an item link from a conversation (does not delete the item itself)
+    async fn delete_item(
+        &self,
+        conversation_id: &ConversationId,
+        item_id: &ConversationItemId,
+    ) -> Result<()>;
 }
 
 pub type SharedConversationItemStorage = Arc<dyn ConversationItemStorage>;
 
 /// Helper to build id prefix based on item_type
 pub fn make_item_id(item_type: &str) -> ConversationItemId {
-    // Generate a 24-byte random hex string (48 hex chars), consistent with conversation id style
+    // Generate exactly 50 hex characters (25 bytes) for the part after the underscore
     let mut rng = rand::rng();
-    let mut bytes = [0u8; 24];
+    let mut bytes = [0u8; 25];
     rng.fill_bytes(&mut bytes);
     let hex_string: String = bytes.iter().map(|b| format!("{:02x}", b)).collect();
 

sgl-router/src/routers/mod.rs

@@ -190,6 +190,50 @@ pub trait RouterTrait: Send + Sync + Debug {
             .into_response()
     }
 
+    /// Create items in a conversation
+    async fn create_conversation_items(
+        &self,
+        _headers: Option<&HeaderMap>,
+        _conversation_id: &str,
+        _body: &Value,
+    ) -> Response {
+        (
+            StatusCode::NOT_IMPLEMENTED,
+            "Conversation items create endpoint not implemented",
+        )
+            .into_response()
+    }
+
+    /// Get a single conversation item
+    /// The `include` parameter is accepted but not yet implemented
+    async fn get_conversation_item(
+        &self,
+        _headers: Option<&HeaderMap>,
+        _conversation_id: &str,
+        _item_id: &str,
+        _include: Option<Vec<String>>,
+    ) -> Response {
+        (
+            StatusCode::NOT_IMPLEMENTED,
+            "Conversation item get endpoint not implemented",
+        )
+            .into_response()
+    }
+
+    /// Delete a conversation item
+    async fn delete_conversation_item(
+        &self,
+        _headers: Option<&HeaderMap>,
+        _conversation_id: &str,
+        _item_id: &str,
+    ) -> Response {
+        (
+            StatusCode::NOT_IMPLEMENTED,
+            "Conversation item delete endpoint not implemented",
+        )
+            .into_response()
+    }
+
     /// Get router type name
     fn router_type(&self) -> &'static str;
 

sgl-router/src/routers/openai/mcp.rs

@@ -829,7 +829,8 @@ pub(super) fn build_incomplete_response(
 pub(super) fn generate_mcp_id(prefix: &str) -> String {
     use rand::RngCore;
     let mut rng = rand::rng();
-    let mut bytes = [0u8; 30];
+    // Generate exactly 50 hex characters (25 bytes) for the part after the underscore
+    let mut bytes = [0u8; 25];
     rng.fill_bytes(&mut bytes);
     let hex_string: String = bytes.iter().map(|b| format!("{:02x}", b)).collect();
     format!("{}_{}", prefix, hex_string)

sgl-router/src/routers/openai/responses.rs

 //! Response storage, patching, and extraction utilities
 
-use crate::data_connector::{ResponseId, SharedResponseStorage, StoredResponse};
+use crate::data_connector::{ResponseId, StoredResponse};
 use crate::protocols::spec::{ResponseInput, ResponseToolType, ResponsesRequest};
 use serde_json::{json, Value};
 use std::collections::HashMap;
-use tracing::{info, warn};
+use tracing::warn;
 
 use super::utils::event_types;
 
@@ -12,25 +12,6 @@ use super::utils::event_types;
 // Response Storage Operations
 // ============================================================================
 
-/// Store a response internally (checks if storage is enabled)
-pub(super) async fn store_response_internal(
-    response_storage: &SharedResponseStorage,
-    response_json: &Value,
-    original_body: &ResponsesRequest,
-) -> Result<(), String> {
-    if !original_body.store {
-        return Ok(());
-    }
-
-    match store_response_impl(response_storage, response_json, original_body).await {
-        Ok(response_id) => {
-            info!(response_id = %response_id.0, "Stored response locally");
-            Ok(())
-        }
-        Err(e) => Err(e),
-    }
-}
-
 /// Build a StoredResponse from response JSON and original request
 pub(super) fn build_stored_response(
     response_json: &Value,
@@ -98,20 +79,6 @@ pub(super) fn build_stored_response(
     stored_response
 }
 
-/// Store response implementation (public for use across modules)
-pub(super) async fn store_response_impl(
-    response_storage: &SharedResponseStorage,
-    response_json: &Value,
-    original_body: &ResponsesRequest,
-) -> Result<ResponseId, String> {
-    let stored_response = build_stored_response(response_json, original_body);
-
-    response_storage
-        .store_response(stored_response)
-        .await
-        .map_err(|e| format!("Failed to store response: {}", e))
-}
-
 // ============================================================================
 // Response JSON Patching
 // ============================================================================

sgl-router/src/routers/openai/router.rs

@@ -31,14 +31,15 @@ use tracing::{info, warn};
 
 // Import from sibling modules
 use super::conversations::{
-    create_conversation, delete_conversation, get_conversation, list_conversation_items,
-    persist_conversation_items, update_conversation,
+    create_conversation, create_conversation_items, delete_conversation, delete_conversation_item,
+    get_conversation, get_conversation_item, list_conversation_items, persist_conversation_items,
+    update_conversation,
 };
 use super::mcp::{
     execute_tool_loop, mcp_manager_from_request_tools, prepare_mcp_payload_for_streaming,
     McpLoopConfig,
 };
-use super::responses::{mask_tools_as_mcp, patch_streaming_response_json, store_response_internal};
+use super::responses::{mask_tools_as_mcp, patch_streaming_response_json};
 use super::streaming::handle_streaming_response;
 
 // ============================================================================
@@ -230,8 +231,7 @@ impl OpenAIRouter {
             original_previous_response_id.as_deref(),
         );
 
-        // Persist conversation items if conversation is provided
-        if original_body.conversation.is_some() {
+        // Always persist conversation items and response (even without conversation)
         if let Err(err) = persist_conversation_items(
             self.conversation_storage.clone(),
             self.conversation_item_storage.clone(),
@@ -243,14 +243,6 @@ impl OpenAIRouter {
         {
             warn!("Failed to persist conversation items: {}", err);
         }
-        } else {
-            // Store response only if no conversation (persist_conversation_items already stores it)
-            if let Err(err) =
-                store_response_internal(&self.response_storage, &response_json, original_body).await
-            {
-                warn!("Failed to store response: {}", err);
-            }
-        }
 
         (StatusCode::OK, Json(response_json)).into_response()
     }
@@ -906,4 +898,51 @@ impl crate::routers::RouterTrait for OpenAIRouter {
         )
         .await
     }
+
+    async fn create_conversation_items(
+        &self,
+        _headers: Option<&HeaderMap>,
+        conversation_id: &str,
+        body: &Value,
+    ) -> Response {
+        create_conversation_items(
+            &self.conversation_storage,
+            &self.conversation_item_storage,
+            conversation_id,
+            body.clone(),
+        )
+        .await
+    }
+
+    async fn get_conversation_item(
+        &self,
+        _headers: Option<&HeaderMap>,
+        conversation_id: &str,
+        item_id: &str,
+        include: Option<Vec<String>>,
+    ) -> Response {
+        get_conversation_item(
+            &self.conversation_storage,
+            &self.conversation_item_storage,
+            conversation_id,
+            item_id,
+            include,
+        )
+        .await
+    }
+
+    async fn delete_conversation_item(
+        &self,
+        _headers: Option<&HeaderMap>,
+        conversation_id: &str,
+        item_id: &str,
+    ) -> Response {
+        delete_conversation_item(
+            &self.conversation_storage,
+            &self.conversation_item_storage,
+            conversation_id,
+            item_id,
+        )
+        .await
+    }
 }

sgl-router/src/routers/openai/streaming.rs

@@ -32,9 +32,7 @@ use super::mcp::{
     mcp_manager_from_request_tools, prepare_mcp_payload_for_streaming, send_mcp_list_tools_events,
     McpLoopConfig, ToolLoopState,
 };
-use super::responses::{
-    mask_tools_as_mcp, patch_streaming_response_json, rewrite_streaming_block, store_response_impl,
-};
+use super::responses::{mask_tools_as_mcp, patch_streaming_response_json, rewrite_streaming_block};
 use super::utils::{event_types, FunctionCallInProgress, OutputIndexMapper, StreamAction};
 
 // ============================================================================
@@ -1082,7 +1080,7 @@ pub(super) async fn handle_simple_streaming_passthrough(
                     previous_response_id.as_deref(),
                 );
 
-                if persist_needed {
+                // Always persist conversation items and response (even without conversation)
                 if let Err(err) = persist_conversation_items(
                     conversation_storage.clone(),
                     conversation_item_storage.clone(),
@@ -1094,15 +1092,6 @@ pub(super) async fn handle_simple_streaming_passthrough(
                 {
                     warn!("Failed to persist conversation items (stream): {}", err);
                 }
-                } else if should_store {
-                    // Store response only if no conversation (persist_conversation_items already stores it)
-                    if let Err(err) =
-                        store_response_impl(&response_storage, &response_json, &original_request)
-                            .await
-                    {
-                        warn!("Failed to store streaming response: {}", err);
-                    }
-                }
             } else if let Some(error_payload) = encountered_error {
                 warn!("Upstream streaming error payload: {}", error_payload);
             } else {
@@ -1390,7 +1379,7 @@ pub(super) async fn handle_streaming_with_tool_interception(
                         previous_response_id.as_deref(),
                     );
 
-                    if persist_needed {
+                    // Always persist conversation items and response (even without conversation)
                     if let Err(err) = persist_conversation_items(
                         conversation_storage.clone(),
                         conversation_item_storage.clone(),
@@ -1405,18 +1394,6 @@ pub(super) async fn handle_streaming_with_tool_interception(
                             err
                         );
                     }
-                    } else if should_store {
-                        // Store response only if no conversation (persist_conversation_items already stores it)
-                        if let Err(err) = store_response_impl(
-                            &response_storage,
-                            &response_json,
-                            &original_request,
-                        )
-                        .await
-                        {
-                            warn!("Failed to store streaming response: {}", err);
-                        }
-                    }
                 }
 
                 let _ = tx.send(Ok(Bytes::from("data: [DONE]\n\n")));

sgl-router/src/routers/router_manager.rs

@@ -614,6 +614,76 @@ impl RouterTrait for RouterManager {
                 .into_response()
         }
     }
+
+    async fn create_conversation_items(
+        &self,
+        headers: Option<&HeaderMap>,
+        conversation_id: &str,
+        body: &Value,
+    ) -> Response {
+        let router = self.select_router_for_request(headers, None);
+        if let Some(router) = router {
+            router
+                .create_conversation_items(headers, conversation_id, body)
+                .await
+        } else {
+            (
+                StatusCode::NOT_FOUND,
+                format!(
+                    "No router available to create conversation items for '{}'",
+                    conversation_id
+                ),
+            )
+                .into_response()
+        }
+    }
+
+    async fn get_conversation_item(
+        &self,
+        headers: Option<&HeaderMap>,
+        conversation_id: &str,
+        item_id: &str,
+        include: Option<Vec<String>>,
+    ) -> Response {
+        let router = self.select_router_for_request(headers, None);
+        if let Some(router) = router {
+            router
+                .get_conversation_item(headers, conversation_id, item_id, include)
+                .await
+        } else {
+            (
+                StatusCode::NOT_FOUND,
+                format!(
+                    "No router available to get conversation item '{}' in '{}'",
+                    item_id, conversation_id
+                ),
+            )
+                .into_response()
+        }
+    }
+
+    async fn delete_conversation_item(
+        &self,
+        headers: Option<&HeaderMap>,
+        conversation_id: &str,
+        item_id: &str,
+    ) -> Response {
+        let router = self.select_router_for_request(headers, None);
+        if let Some(router) = router {
+            router
+                .delete_conversation_item(headers, conversation_id, item_id)
+                .await
+        } else {
+            (
+                StatusCode::NOT_FOUND,
+                format!(
+                    "No router available to delete conversation item '{}' in '{}'",
+                    item_id, conversation_id
+                ),
+            )
+                .into_response()
+        }
+    }
 }
 
 impl std::fmt::Debug for RouterManager {

sgl-router/src/server.rs

@@ -440,6 +440,47 @@ async fn v1_conversations_list_items(
         .await
 }
 
+#[derive(Deserialize, Default)]
+struct GetItemQuery {
+    /// Additional fields to include in response (not yet implemented)
+    include: Option<Vec<String>>,
+}
+
+async fn v1_conversations_create_items(
+    State(state): State<Arc<AppState>>,
+    Path(conversation_id): Path<String>,
+    headers: http::HeaderMap,
+    Json(body): Json<Value>,
+) -> Response {
+    state
+        .router
+        .create_conversation_items(Some(&headers), &conversation_id, &body)
+        .await
+}
+
+async fn v1_conversations_get_item(
+    State(state): State<Arc<AppState>>,
+    Path((conversation_id, item_id)): Path<(String, String)>,
+    Query(query): Query<GetItemQuery>,
+    headers: http::HeaderMap,
+) -> Response {
+    state
+        .router
+        .get_conversation_item(Some(&headers), &conversation_id, &item_id, query.include)
+        .await
+}
+
+async fn v1_conversations_delete_item(
+    State(state): State<Arc<AppState>>,
+    Path((conversation_id, item_id)): Path<(String, String)>,
+    headers: http::HeaderMap,
+) -> Response {
+    state
+        .router
+        .delete_conversation_item(Some(&headers), &conversation_id, &item_id)
+        .await
+}
+
 #[derive(Deserialize)]
 struct AddWorkerQuery {
     url: String,
@@ -716,7 +757,11 @@ pub fn build_app(
         )
         .route(
             "/v1/conversations/{conversation_id}/items",
-            get(v1_conversations_list_items),
+            get(v1_conversations_list_items).post(v1_conversations_create_items),
+        )
+        .route(
+            "/v1/conversations/{conversation_id}/items/{item_id}",
+            get(v1_conversations_get_item).delete(v1_conversations_delete_item),
         )
         .route_layer(axum::middleware::from_fn_with_state(
             app_state.clone(),

sgl-router/tests/responses_api_test.rs

@@ -1333,3 +1333,519 @@ async fn test_streaming_multi_turn_with_mcp() {
     worker.stop().await;
     mcp.stop().await;
 }
+
+#[tokio::test]
+async fn test_conversation_items_create_and_get() {
+    // Test creating items and getting a specific item
+    let router_cfg = RouterConfig {
+        mode: RoutingMode::OpenAI {
+            worker_urls: vec!["http://localhost".to_string()],
+        },
+        connection_mode: ConnectionMode::Http,
+        policy: PolicyConfig::Random,
+        host: "127.0.0.1".to_string(),
+        port: 0,
+        max_payload_size: 8 * 1024 * 1024,
+        request_timeout_secs: 60,
+        worker_startup_timeout_secs: 1,
+        worker_startup_check_interval_secs: 1,
+        dp_aware: false,
+        api_key: None,
+        discovery: None,
+        metrics: None,
+        log_dir: None,
+        log_level: Some("warn".to_string()),
+        request_id_headers: None,
+        max_concurrent_requests: 8,
+        queue_size: 0,
+        queue_timeout_secs: 5,
+        rate_limit_tokens_per_second: None,
+        cors_allowed_origins: vec![],
+        retry: RetryConfig::default(),
+        circuit_breaker: CircuitBreakerConfig::default(),
+        disable_retries: false,
+        disable_circuit_breaker: false,
+        health_check: HealthCheckConfig::default(),
+        enable_igw: false,
+        model_path: None,
+        tokenizer_path: None,
+        history_backend: sglang_router_rs::config::HistoryBackend::Memory,
+        oracle: None,
+        reasoning_parser: None,
+        tool_call_parser: None,
+    };
+
+    let ctx = AppContext::new(router_cfg, reqwest::Client::new(), 8, None).expect("ctx");
+    let router = RouterFactory::create_router(&Arc::new(ctx))
+        .await
+        .expect("router");
+
+    // Create conversation
+    let create_conv = serde_json::json!({});
+    let conv_resp = router.create_conversation(None, &create_conv).await;
+    assert_eq!(conv_resp.status(), StatusCode::OK);
+    let conv_bytes = axum::body::to_bytes(conv_resp.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let conv_json: serde_json::Value = serde_json::from_slice(&conv_bytes).unwrap();
+    let conv_id = conv_json["id"].as_str().unwrap();
+
+    // Create items
+    let create_items = serde_json::json!({
+        "items": [
+            {
+                "type": "message",
+                "role": "user",
+                "content": [{"type": "input_text", "text": "Hello"}]
+            },
+            {
+                "type": "message",
+                "role": "assistant",
+                "content": [{"type": "output_text", "text": "Hi there!"}]
+            }
+        ]
+    });
+
+    let items_resp = router
+        .create_conversation_items(None, conv_id, &create_items)
+        .await;
+    assert_eq!(items_resp.status(), StatusCode::OK);
+    let items_bytes = axum::body::to_bytes(items_resp.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let items_json: serde_json::Value = serde_json::from_slice(&items_bytes).unwrap();
+
+    // Verify response structure
+    assert_eq!(items_json["object"], "list");
+    assert!(items_json["data"].is_array());
+
+    // Get first item
+    let item_id = items_json["data"][0]["id"].as_str().unwrap();
+    let get_resp = router
+        .get_conversation_item(None, conv_id, item_id, None)
+        .await;
+    assert_eq!(get_resp.status(), StatusCode::OK);
+    let get_bytes = axum::body::to_bytes(get_resp.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let get_json: serde_json::Value = serde_json::from_slice(&get_bytes).unwrap();
+
+    // Verify item structure
+    assert_eq!(get_json["id"], item_id);
+    assert_eq!(get_json["type"], "message");
+    assert_eq!(get_json["role"], "user");
+}
+
+#[tokio::test]
+async fn test_conversation_items_delete() {
+    // Test deleting an item from a conversation
+    let router_cfg = RouterConfig {
+        mode: RoutingMode::OpenAI {
+            worker_urls: vec!["http://localhost".to_string()],
+        },
+        connection_mode: ConnectionMode::Http,
+        policy: PolicyConfig::Random,
+        host: "127.0.0.1".to_string(),
+        port: 0,
+        max_payload_size: 8 * 1024 * 1024,
+        request_timeout_secs: 60,
+        worker_startup_timeout_secs: 1,
+        worker_startup_check_interval_secs: 1,
+        dp_aware: false,
+        api_key: None,
+        discovery: None,
+        metrics: None,
+        log_dir: None,
+        log_level: Some("warn".to_string()),
+        request_id_headers: None,
+        max_concurrent_requests: 8,
+        queue_size: 0,
+        queue_timeout_secs: 5,
+        rate_limit_tokens_per_second: None,
+        cors_allowed_origins: vec![],
+        retry: RetryConfig::default(),
+        circuit_breaker: CircuitBreakerConfig::default(),
+        disable_retries: false,
+        disable_circuit_breaker: false,
+        health_check: HealthCheckConfig::default(),
+        enable_igw: false,
+        model_path: None,
+        tokenizer_path: None,
+        history_backend: sglang_router_rs::config::HistoryBackend::Memory,
+        oracle: None,
+        reasoning_parser: None,
+        tool_call_parser: None,
+    };
+
+    let ctx = AppContext::new(router_cfg, reqwest::Client::new(), 8, None).expect("ctx");
+    let router = RouterFactory::create_router(&Arc::new(ctx))
+        .await
+        .expect("router");
+
+    // Create conversation
+    let create_conv = serde_json::json!({});
+    let conv_resp = router.create_conversation(None, &create_conv).await;
+    let conv_bytes = axum::body::to_bytes(conv_resp.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let conv_json: serde_json::Value = serde_json::from_slice(&conv_bytes).unwrap();
+    let conv_id = conv_json["id"].as_str().unwrap();
+
+    // Create item
+    let create_items = serde_json::json!({
+        "items": [
+            {
+                "type": "message",
+                "role": "user",
+                "content": [{"type": "input_text", "text": "Test"}]
+            }
+        ]
+    });
+
+    let items_resp = router
+        .create_conversation_items(None, conv_id, &create_items)
+        .await;
+    let items_bytes = axum::body::to_bytes(items_resp.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let items_json: serde_json::Value = serde_json::from_slice(&items_bytes).unwrap();
+    let item_id = items_json["data"][0]["id"].as_str().unwrap();
+
+    // List items (should have 1)
+    let list_resp = router
+        .list_conversation_items(None, conv_id, None, None, None)
+        .await;
+    let list_bytes = axum::body::to_bytes(list_resp.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let list_json: serde_json::Value = serde_json::from_slice(&list_bytes).unwrap();
+    assert_eq!(list_json["data"].as_array().unwrap().len(), 1);
+
+    // Delete item
+    let del_resp = router
+        .delete_conversation_item(None, conv_id, item_id)
+        .await;
+    assert_eq!(del_resp.status(), StatusCode::OK);
+
+    // List items again (should have 0)
+    let list_resp2 = router
+        .list_conversation_items(None, conv_id, None, None, None)
+        .await;
+    let list_bytes2 = axum::body::to_bytes(list_resp2.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let list_json2: serde_json::Value = serde_json::from_slice(&list_bytes2).unwrap();
+    assert_eq!(list_json2["data"].as_array().unwrap().len(), 0);
+
+    // Item should NOT be gettable from this conversation after deletion (link removed)
+    let get_resp = router
+        .get_conversation_item(None, conv_id, item_id, None)
+        .await;
+    assert_eq!(get_resp.status(), StatusCode::NOT_FOUND);
+}
+
+#[tokio::test]
+async fn test_conversation_items_max_limit() {
+    // Test that creating > 20 items returns error
+    let router_cfg = RouterConfig {
+        mode: RoutingMode::OpenAI {
+            worker_urls: vec!["http://localhost".to_string()],
+        },
+        connection_mode: ConnectionMode::Http,
+        policy: PolicyConfig::Random,
+        host: "127.0.0.1".to_string(),
+        port: 0,
+        max_payload_size: 8 * 1024 * 1024,
+        request_timeout_secs: 60,
+        worker_startup_timeout_secs: 1,
+        worker_startup_check_interval_secs: 1,
+        dp_aware: false,
+        api_key: None,
+        discovery: None,
+        metrics: None,
+        log_dir: None,
+        log_level: Some("warn".to_string()),
+        request_id_headers: None,
+        max_concurrent_requests: 8,
+        queue_size: 0,
+        queue_timeout_secs: 5,
+        rate_limit_tokens_per_second: None,
+        cors_allowed_origins: vec![],
+        retry: RetryConfig::default(),
+        circuit_breaker: CircuitBreakerConfig::default(),
+        disable_retries: false,
+        disable_circuit_breaker: false,
+        health_check: HealthCheckConfig::default(),
+        enable_igw: false,
+        model_path: None,
+        tokenizer_path: None,
+        history_backend: sglang_router_rs::config::HistoryBackend::Memory,
+        oracle: None,
+        reasoning_parser: None,
+        tool_call_parser: None,
+    };
+
+    let ctx = AppContext::new(router_cfg, reqwest::Client::new(), 8, None).expect("ctx");
+    let router = RouterFactory::create_router(&Arc::new(ctx))
+        .await
+        .expect("router");
+
+    // Create conversation
+    let create_conv = serde_json::json!({});
+    let conv_resp = router.create_conversation(None, &create_conv).await;
+    let conv_bytes = axum::body::to_bytes(conv_resp.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let conv_json: serde_json::Value = serde_json::from_slice(&conv_bytes).unwrap();
+    let conv_id = conv_json["id"].as_str().unwrap();
+
+    // Try to create 21 items (over limit)
+    let mut items = Vec::new();
+    for i in 0..21 {
+        items.push(serde_json::json!({
+            "type": "message",
+            "role": "user",
+            "content": [{"type": "input_text", "text": format!("Message {}", i)}]
+        }));
+    }
+    let create_items = serde_json::json!({"items": items});
+
+    let items_resp = router
+        .create_conversation_items(None, conv_id, &create_items)
+        .await;
+    assert_eq!(items_resp.status(), StatusCode::BAD_REQUEST);
+
+    let items_bytes = axum::body::to_bytes(items_resp.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let items_text = String::from_utf8_lossy(&items_bytes);
+    assert!(items_text.contains("Cannot add more than 20 items"));
+}
+
+#[tokio::test]
+async fn test_conversation_items_unsupported_type() {
+    // Test that unsupported item types return error
+    let router_cfg = RouterConfig {
+        mode: RoutingMode::OpenAI {
+            worker_urls: vec!["http://localhost".to_string()],
+        },
+        connection_mode: ConnectionMode::Http,
+        policy: PolicyConfig::Random,
+        host: "127.0.0.1".to_string(),
+        port: 0,
+        max_payload_size: 8 * 1024 * 1024,
+        request_timeout_secs: 60,
+        worker_startup_timeout_secs: 1,
+        worker_startup_check_interval_secs: 1,
+        dp_aware: false,
+        api_key: None,
+        discovery: None,
+        metrics: None,
+        log_dir: None,
+        log_level: Some("warn".to_string()),
+        request_id_headers: None,
+        max_concurrent_requests: 8,
+        queue_size: 0,
+        queue_timeout_secs: 5,
+        rate_limit_tokens_per_second: None,
+        cors_allowed_origins: vec![],
+        retry: RetryConfig::default(),
+        circuit_breaker: CircuitBreakerConfig::default(),
+        disable_retries: false,
+        disable_circuit_breaker: false,
+        health_check: HealthCheckConfig::default(),
+        enable_igw: false,
+        model_path: None,
+        tokenizer_path: None,
+        history_backend: sglang_router_rs::config::HistoryBackend::Memory,
+        oracle: None,
+        reasoning_parser: None,
+        tool_call_parser: None,
+    };
+
+    let ctx = AppContext::new(router_cfg, reqwest::Client::new(), 8, None).expect("ctx");
+    let router = RouterFactory::create_router(&Arc::new(ctx))
+        .await
+        .expect("router");
+
+    // Create conversation
+    let create_conv = serde_json::json!({});
+    let conv_resp = router.create_conversation(None, &create_conv).await;
+    let conv_bytes = axum::body::to_bytes(conv_resp.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let conv_json: serde_json::Value = serde_json::from_slice(&conv_bytes).unwrap();
+    let conv_id = conv_json["id"].as_str().unwrap();
+
+    // Try to create item with completely unsupported type
+    let create_items = serde_json::json!({
+        "items": [
+            {
+                "type": "totally_invalid_type",
+                "content": []
+            }
+        ]
+    });
+
+    let items_resp = router
+        .create_conversation_items(None, conv_id, &create_items)
+        .await;
+    assert_eq!(items_resp.status(), StatusCode::BAD_REQUEST);
+
+    let items_bytes = axum::body::to_bytes(items_resp.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let items_text = String::from_utf8_lossy(&items_bytes);
+    assert!(items_text.contains("Unsupported item type"));
+}
+
+#[tokio::test]
+async fn test_conversation_items_multi_conversation_sharing() {
+    // Test that items can be shared across conversations via soft delete
+    let router_cfg = RouterConfig {
+        mode: RoutingMode::OpenAI {
+            worker_urls: vec!["http://localhost".to_string()],
+        },
+        connection_mode: ConnectionMode::Http,
+        policy: PolicyConfig::Random,
+        host: "127.0.0.1".to_string(),
+        port: 0,
+        max_payload_size: 8 * 1024 * 1024,
+        request_timeout_secs: 60,
+        worker_startup_timeout_secs: 1,
+        worker_startup_check_interval_secs: 1,
+        dp_aware: false,
+        api_key: None,
+        discovery: None,
+        metrics: None,
+        log_dir: None,
+        log_level: Some("warn".to_string()),
+        request_id_headers: None,
+        max_concurrent_requests: 8,
+        queue_size: 0,
+        queue_timeout_secs: 5,
+        rate_limit_tokens_per_second: None,
+        cors_allowed_origins: vec![],
+        retry: RetryConfig::default(),
+        circuit_breaker: CircuitBreakerConfig::default(),
+        disable_retries: false,
+        disable_circuit_breaker: false,
+        health_check: HealthCheckConfig::default(),
+        enable_igw: false,
+        model_path: None,
+        tokenizer_path: None,
+        history_backend: sglang_router_rs::config::HistoryBackend::Memory,
+        oracle: None,
+        reasoning_parser: None,
+        tool_call_parser: None,
+    };
+
+    let ctx = AppContext::new(router_cfg, reqwest::Client::new(), 8, None).expect("ctx");
+    let router = RouterFactory::create_router(&Arc::new(ctx))
+        .await
+        .expect("router");
+
+    // Create two conversations
+    let conv_a_resp = router
+        .create_conversation(None, &serde_json::json!({}))
+        .await;
+    let conv_a_bytes = axum::body::to_bytes(conv_a_resp.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let conv_a_json: serde_json::Value = serde_json::from_slice(&conv_a_bytes).unwrap();
+    let conv_a_id = conv_a_json["id"].as_str().unwrap();
+
+    let conv_b_resp = router
+        .create_conversation(None, &serde_json::json!({}))
+        .await;
+    let conv_b_bytes = axum::body::to_bytes(conv_b_resp.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let conv_b_json: serde_json::Value = serde_json::from_slice(&conv_b_bytes).unwrap();
+    let conv_b_id = conv_b_json["id"].as_str().unwrap();
+
+    // Create item in conversation A
+    let create_items = serde_json::json!({
+        "items": [
+            {
+                "type": "message",
+                "role": "user",
+                "content": [{"type": "input_text", "text": "Shared message"}]
+            }
+        ]
+    });
+
+    let items_a_resp = router
+        .create_conversation_items(None, conv_a_id, &create_items)
+        .await;
+    let items_a_bytes = axum::body::to_bytes(items_a_resp.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let items_a_json: serde_json::Value = serde_json::from_slice(&items_a_bytes).unwrap();
+    let item_id = items_a_json["data"][0]["id"].as_str().unwrap();
+
+    // Reference the same item in conversation B
+    let reference_items = serde_json::json!({
+        "items": [
+            {
+                "type": "item_reference",
+                "id": item_id
+            }
+        ]
+    });
+
+    let items_b_resp = router
+        .create_conversation_items(None, conv_b_id, &reference_items)
+        .await;
+    assert_eq!(items_b_resp.status(), StatusCode::OK);
+
+    // Verify item appears in both conversations
+    let list_a = router
+        .list_conversation_items(None, conv_a_id, None, None, None)
+        .await;
+    let list_a_bytes = axum::body::to_bytes(list_a.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let list_a_json: serde_json::Value = serde_json::from_slice(&list_a_bytes).unwrap();
+    assert_eq!(list_a_json["data"].as_array().unwrap().len(), 1);
+
+    let list_b = router
+        .list_conversation_items(None, conv_b_id, None, None, None)
+        .await;
+    let list_b_bytes = axum::body::to_bytes(list_b.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let list_b_json: serde_json::Value = serde_json::from_slice(&list_b_bytes).unwrap();
+    assert_eq!(list_b_json["data"].as_array().unwrap().len(), 1);
+
+    // Delete from conversation A
+    router
+        .delete_conversation_item(None, conv_a_id, item_id)
+        .await;
+
+    // Should be removed from A
+    let list_a2 = router
+        .list_conversation_items(None, conv_a_id, None, None, None)
+        .await;
+    let list_a2_bytes = axum::body::to_bytes(list_a2.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let list_a2_json: serde_json::Value = serde_json::from_slice(&list_a2_bytes).unwrap();
+    assert_eq!(list_a2_json["data"].as_array().unwrap().len(), 0);
+
+    // Should still exist in B (soft delete)
+    let list_b2 = router
+        .list_conversation_items(None, conv_b_id, None, None, None)
+        .await;
+    let list_b2_bytes = axum::body::to_bytes(list_b2.into_body(), usize::MAX)
+        .await
+        .unwrap();
+    let list_b2_json: serde_json::Value = serde_json::from_slice(&list_b2_bytes).unwrap();
+    assert_eq!(list_b2_json["data"].as_array().unwrap().len(), 1);
+
+    // Item should still be directly gettable
+    let get_resp = router
+        .get_conversation_item(None, conv_b_id, item_id, None)
+        .await;
+    assert_eq!(get_resp.status(), StatusCode::OK);
+}