Notify client when tool list changed

README.md

@@ -58,7 +58,7 @@ npx -y di-mcp-server --authentication-mode basic --basic-username <YOUR_USERNAME
 
 Syntax of the command line:
 ```bash
-npx -y di-mcp-server [--authentication-mode <AUTHENTICATION_MODE>] <CREDENTIALS> --url <RUNTIME_BASE_URL> [--transport <TRANSPORT>] [--deployment-spaces <DEPLOYMENT_SPACES>] [--decision-service-ids <DECISION_SERVICE_IDS>]
+npx -y di-mcp-server [--authentication-mode <AUTHENTICATION_MODE>] <CREDENTIALS> --url <RUNTIME_BASE_URL> [--transport <TRANSPORT>] [--deployment-spaces <DEPLOYMENT_SPACES>] [--decision-service-ids <DECISION_SERVICE_IDS>] [--poll-interval <POLL_INTERVAL>]
 ```
 
 where
@@ -71,6 +71,7 @@ where
 - `TRANSPORT` (optional) is the transport protocol, either `stdio` (default) or `http`.
 - `DEPLOYMENT_SPACES` (optional) is a comma-separated list of deployment spaces to scan (defaults to `development`).
 - `DECISION_SERVICE_IDS` (optional) If defined, comma-separated list of decision service ids to be exposed as tools
+- `POLL_INTERVAL` (optional) is the interval in milliseconds for polling tool changes (defaults to `30000` i.e. 30s), minimum: `1000` i.e. 1s)
 
 The following environment variables can be used in addition to the command line options.
 
@@ -85,6 +86,7 @@ The following environment variables can be used in addition to the command line
 | --decision-service-ids | DECISION_SERVICE_IDS | Optional comma-separated list of decision services (default: fetch all decision services)                    |
 | --deployment-spaces    | DEPLOYMENT_SPACES    | Optional comma-separated list of deployment spaces to scan (default: `development`)                          |
 | --debug                | DEBUG                | When the value is `true`, the debug messages are written to the `stderr` of the MCP server                   |
+| --poll-interval        | POLL_INTERVAL        | Optional interval in milliseconds for polling tool changes (default: `30000` i.e. 30s, minimum: `1000` i.e 1s)               |
 | --transport            | TRANSPORT            | Optional transport protocol: `stdio` (default) or `http`                                                     |
 | --url                  | URL                  | Base URL of the decision runtime </br>                                                                       |
 
@@ -246,6 +248,48 @@ If the default naming strategy doesn't meet the requirements of your MCP hosts,
 where
 - `OPERATION_ID` is the operation unique identifier
 - `YourCustomToolName` is the desired tool name for the operation
+## Dynamic Tool Updates
+
+The MCP server implements the `listChanged` capability, which allows it to automatically notify connected clients when the list of available tools changes. This feature enables real-time updates without requiring a server restart.
+
+### How it works
+
+1. **Initial Tool Discovery**: When the server starts, it discovers and registers all available decision service operations as MCP tools.
+
+2. **Continuous Monitoring**: The server polls the Decision Intelligence or Automation Decision Services runtime every 30 seconds to check for changes.
+
+3. **Change Detection**: The server detects the following types of changes:
+   - **New tools**: When a new decision service operation is deployed
+   - **Removed tools**: When a decision service operation is undeployed
+   - **Modified tools**: When the input schema of an operation changes
+
+4. **Client Notification**: When changes are detected, the server sends a `notifications/tools/list_changed` notification to all connected clients, prompting them to refresh their tool list.
+
+### Benefits
+
+- **No restart required**: New or updated decision services become available immediately
+- **Automatic synchronization**: Clients stay in sync with the latest decision services
+- **Seamless updates**: Changes are detected and propagated automatically
+
+### Configuration
+
+The dynamic tool update feature is enabled by default and requires no additional configuration. The polling interval defaults to 30 seconds (30000 milliseconds), which provides a good balance between responsiveness and system load.
+
+You can customize the polling interval using the `--poll-interval` option or the `POLL_INTERVAL` environment variable:
+
+```bash
+# Set polling interval to 60 seconds
+npx -y di-mcp-server --di-apikey <YOUR_API_KEY> --url <RUNTIME_URL> --poll-interval 60000
+```
+
+Or using an environment variable:
+```bash
+export POLL_INTERVAL=60000
+npx -y di-mcp-server --di-apikey <YOUR_API_KEY> --url <RUNTIME_URL>
+```
+
+**Note**: The minimum allowed polling interval is 1000 milliseconds (1 second).
+
 
 ## Technical details
 

src/command-line.ts

@@ -33,7 +33,8 @@ export class Configuration {
         public version: string,
         public debugEnabled: boolean,
         public deploymentSpaces: string[] = Configuration.defaultDeploymentSpaces(),
-        public decisionServiceIds: string[] | undefined = undefined
+        public decisionServiceIds: string[] | undefined = undefined,
+        public pollInterval: number = Configuration.defaultPollInterval()
     ) {
     }
 
@@ -45,6 +46,10 @@ export class Configuration {
         return ['development'];
     }
 
+    static defaultPollInterval(): number {
+        return 30000; // 30 seconds in milliseconds
+    }
+
     isStdioTransport(): boolean {
         return this.transport !== undefined;
     }
@@ -168,6 +173,23 @@ function parseDecisionServiceIds(decisionServiceIds: string | undefined): string
     return undefined;
 }
 
+function validatePollInterval(pollInterval: string | undefined): number {
+    debug("POLL_INTERVAL=" + pollInterval);
+    if (pollInterval === undefined) {
+        const defaultPollInterval = Configuration.defaultPollInterval();
+        debug(`The poll interval is not defined. Using '${defaultPollInterval}' milliseconds`);
+        return defaultPollInterval;
+    }
+    const parsedInterval = parseInt(pollInterval, 10);
+    if (isNaN(parsedInterval)) {
+        throw new Error(`Invalid poll interval: '${pollInterval}'. Must be a valid number in milliseconds.`);
+    }
+    if (parsedInterval < 1000) {
+        throw new Error(`Invalid poll interval: '${pollInterval}'. Must be at least 1000 milliseconds (1 second).`);
+    }
+    return parsedInterval;
+}
+
 export function createConfiguration(version: string, cliArguments?: readonly string[]): Configuration {
     const program = new Command();
     program
@@ -184,7 +206,8 @@ export function createConfiguration(version: string, cliArguments?: readonly str
         .option('--basic-password <string>', "Password for the basic authentication")
         .option('--transport <transport>', "Transport mode: 'stdio' or 'http'")
         .option('--deployment-spaces <list>', "Comma-separated list of deployment spaces to scan (default: 'development')")
-        .option('--decision-service-ids <list>', 'If defined, comma-separated list of decision service ids to be exposed as tools');
+        .option('--decision-service-ids <list>', 'If defined, comma-separated list of decision service ids to be exposed as tools')
+        .option('--poll-interval <milliseconds>', 'Interval in milliseconds for polling tool changes (default: 30000, minimum: 1000)');
 
     program.parse(cliArguments);
 
@@ -198,7 +221,8 @@ export function createConfiguration(version: string, cliArguments?: readonly str
     const url = validateUrl(options.url || process.env.URL);
     const deploymentSpaces = validateDeploymentSpaces(options.deploymentSpaces || process.env.DEPLOYMENT_SPACES);
     const decisionServiceIds = parseDecisionServiceIds(options.decisionServiceIds || process.env.DECISION_SERVICE_IDS);
+    const pollInterval = validatePollInterval(options.pollInterval || process.env.POLL_INTERVAL);
 
     // Create and return configuration object
-    return new Configuration(credentials, transport, url, version, debugFlag, deploymentSpaces, decisionServiceIds);
+    return new Configuration(credentials, transport, url, version, debugFlag, deploymentSpaces, decisionServiceIds, pollInterval);
 }