Support enable/disable tool servers

Author: ericdallo

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+- Support enable/disable tool servers.
+- Bump mcp java sdk to 0.11.0.
+
 ## 0.13.1
 
 - Improve ollama model listing getting capabilities, avoiding change ollama config for different models.

deps.edn

@@ -3,7 +3,7 @@
         org.clojure/core.async {:mvn/version "1.8.741"}
         org.babashka/cli {:mvn/version "0.8.65"}
         com.github.clojure-lsp/lsp4clj {:mvn/version "1.13.1"}
-        io.modelcontextprotocol.sdk/mcp {:mvn/version "0.10.0"}
+        io.modelcontextprotocol.sdk/mcp {:mvn/version "0.11.0"}
         borkdude/dynaload {:mvn/version "0.3.5"}
         babashka/fs {:mvn/version "0.5.26"}
         hato/hato {:mvn/version "1.0.0"}

docs/protocol.md

@@ -845,14 +845,11 @@ A server notification about a tool status update like a MCP or native tool.
 This is useful for clients present to user the list of configured tools/MCPs,
 their status and available tools and actions.
 
-_Request:_ 
+_Notification:_ 
 
 * method: `tool/serverUpdated`
 * params: `ToolServerUpdatedParams` defined as follows:
 
-_Response:_
-
-
 ```typescript
 type ToolServerUpdatedParams = EcaServerUpdatedParams | MCPServerUpdatedParams;
 
@@ -921,6 +918,44 @@ interface ServerTool {
 }
 ```
 
+### Stop MCP server (➡️)
+
+A client notification for server to stop a MCP server, stopping the process.
+Updates its status via `tool/serverUpdated` notification.
+
+_Notification:_
+
+* method: `mcp/stopServer`
+* params: `MCPStopServerParams` defined as follows:
+
+```typescript
+interface MCPStopServerParams {
+    /**
+     * The MCP server name.
+     */
+    name: string;
+}
+```
+
+### Start MCP server (➡️)
+
+A client notification for server to start a stopped MCP server, starting the process again.
+Updates its status via `tool/serverUpdated` notification.
+
+_Notification:_
+
+* method: `mcp/startServer`
+* params: `MCPStartServerParams` defined as follows:
+
+```typescript
+interface MCPStartServerParams {
+    /**
+     * The server name.
+     */
+    name: string;
+}
+```
+
 ### Add MCP (↩️)
 
 Soon

src/eca/features/tools.clj

@@ -69,3 +69,29 @@
                                                                         (update :tools #(mapv with-tool-status %)))))}
      db*
      config)))
+
+(defn stop-server! [name db* messenger config]
+  (let [disabled-tools (set (get-in config [:disabledTools] []))
+        with-tool-status (fn [tool]
+                           (assoc-some tool :disabled (contains? disabled-tools (:name tool))))]
+    (f.mcp/stop-server!
+     name
+     db*
+     config
+     {:on-server-updated (fn [server]
+                           (messenger/tool-server-updated messenger (-> server
+                                                                        (assoc :type :mcp)
+                                                                        (update :tools #(mapv with-tool-status %)))))})))
+
+(defn start-server! [name db* messenger config]
+  (let [disabled-tools (set (get-in config [:disabledTools] []))
+        with-tool-status (fn [tool]
+                           (assoc-some tool :disabled (contains? disabled-tools (:name tool))))]
+    (f.mcp/start-server!
+     name
+     db*
+     config
+     {:on-server-updated (fn [server]
+                           (messenger/tool-server-updated messenger (-> server
+                                                                        (assoc :type :mcp)
+                                                                        (update :tools #(mapv with-tool-status %)))))})))

src/eca/features/tools/mcp.clj

@@ -102,29 +102,52 @@
                             (.arguments prompt-client))})
         (.prompts (.listPrompts client))))
 
-(defn initialize-servers-async! [{:keys [on-server-updated]} db* config]
-  (let [workspaces (:workspace-folders @db*)
-        db @db*
+(defn ^:private initialize-server! [name db* config on-server-updated]
+  (let [db @db*
+        workspaces (:workspace-folders @db*)
+        server-config (get-in config [:mcpServers (keyword name)])
         obj-mapper (ObjectMapper.)]
-    (doseq [[name server-config] (:mcpServers config)]
-      (when-not (get-in db [:mcp-clients name])
-        (if (get server-config :disabled false)
-          (on-server-updated (->server name server-config :disabled db))
-          (future
-            (try
-              (let [transport (->transport server-config workspaces)
-                    client (->client transport config)]
-                (on-server-updated (->server name server-config :starting db))
-                (swap! db* assoc-in [:mcp-clients name] {:client client})
-                (doseq [{:keys [name uri]} workspaces]
-                  (.addRoot client (McpSchema$Root. uri name)))
-                (.initialize client)
-                (swap! db* assoc-in [:mcp-clients name :tools] (list-server-tools obj-mapper client))
-                (swap! db* assoc-in [:mcp-clients name :prompts] (list-server-prompts client))
-                (on-server-updated (->server name server-config :running @db*)))
-              (catch Exception e
-                (logger/warn logger-tag (format "Could not initialize MCP server %s. Error: %s" name (.getMessage e)))
-                (on-server-updated (->server name server-config :failed db))))))))))
+    (try
+      (let [transport (->transport server-config workspaces)
+            client (->client transport config)]
+        (on-server-updated (->server name server-config :starting db))
+        (swap! db* assoc-in [:mcp-clients name] {:client client})
+        (doseq [{:keys [name uri]} workspaces]
+          (.addRoot client (McpSchema$Root. uri name)))
+        (.initialize client)
+        (swap! db* assoc-in [:mcp-clients name :tools] (list-server-tools obj-mapper client))
+        (swap! db* assoc-in [:mcp-clients name :prompts] (list-server-prompts client))
+        (on-server-updated (->server name server-config :running @db*)))
+      (catch Exception e
+        (logger/warn logger-tag (format "Could not initialize MCP server %s. Error: %s" name (.getMessage e)))
+        (on-server-updated (->server name server-config :failed db))))))
+
+(defn initialize-servers-async! [{:keys [on-server-updated]} db* config]
+  (let [db @db*]
+    (doseq [[name-kwd server-config] (:mcpServers config)]
+      (let [name (name name-kwd)]
+        (when-not (get-in db [:mcp-clients name])
+          (if (get server-config :disabled false)
+            (on-server-updated (->server name server-config :disabled db))
+            (future
+              (initialize-server! name db* config on-server-updated))))))))
+
+(defn stop-server! [name db* config {:keys [on-server-updated]}]
+  (when-let [{:keys [client]} (get-in @db* [:mcp-clients name])]
+    (let [server-config (get-in config [:mcpServers (keyword name)])]
+      (on-server-updated (->server name server-config :stopping @db*))
+      (.closeGracefully ^McpSyncClient client)
+      (swap! db* update :mcp-clients dissoc name)
+      (on-server-updated (->server name server-config :stopped @db*))
+      (logger/info logger-tag (format "Stopped MCP server %s" name)))))
+
+(defn start-server! [name db* config {:keys [on-server-updated]}]
+  (when-let [server-config (get-in config [:mcpServers (keyword name)])]
+    (if (get server-config :disabled false)
+      (logger/warn logger-tag (format "MCP server %s is disabled and cannot be started" name))
+      (do
+        (initialize-server! name db* config on-server-updated)
+        (logger/info logger-tag (format "Started MCP server %s" name))))))
 
 (defn all-tools [db]
   (into []

src/eca/handlers.clj

@@ -98,3 +98,13 @@
    :eca/chat-delete
    (f.chat/delete-chat params db*)
    {}))
+
+(defn mcp-stop-server [{:keys [db* messenger config]} params]
+  (logger/logging-task
+   :eca/mcp-stop-server
+   (f.tools/stop-server! (:name params) db* messenger config)))
+
+(defn mcp-start-server [{:keys [db* messenger config]} params]
+  (logger/logging-task
+   :eca/mcp-start-server
+   (f.tools/start-server! (:name params) db* messenger config)))

src/eca/server.clj

@@ -62,6 +62,12 @@
 (defmethod lsp.server/receive-request "chat/delete" [_ components params]
   (handlers/chat-delete (with-config components) params))
 
+(defmethod lsp.server/receive-notification "mcp/stopServer" [_ components params]
+  (handlers/mcp-stop-server (with-config components) params))
+
+(defmethod lsp.server/receive-notification "mcp/startServer" [_ components params]
+  (handlers/mcp-start-server (with-config components) params))
+
 (defn ^:private monitor-server-logs [log-ch]
   ;; NOTE: if this were moved to `initialize`, after timbre has been configured,
   ;; the server's startup logs and traces would appear in the regular log file