Add metadata to ElicitRequest objects, forward tool call metadata with with the requests. (#369)

Also prepares to publish dart_mcp version 0.5.0.

Some clients require elicitation requests to be associated with a tool call, and they link it using the ProgressToken.

Author: jakemac53

pkgs/dart_mcp/CHANGELOG.md

@@ -1,4 +1,4 @@
-## 0.5.0-wip
+## 0.5.0
 
 - Initial support for protocol version [2025-11-25](https://modelcontextprotocol.io/specification/2025-11-25/).
   - Added support for `Icon`s in `Implementation`, `Tool`, `Resource`, `ResourceTemplate`, and `Prompt`.
@@ -22,6 +22,7 @@
   - Does **not** add support for Tasks yet.
   - Added support for `EnumSchema` subtypes, matching the spec. This includes
     multi select enums and enums with titles. Validation is also supported.
+  - Added `Meta? meta` param to `ElicitRequest`.
 - Added `ConstSchema` type for constant values, with validation.
 - **BREAKING**:
   - Change many fields of `ResourceLink` to be nullable, and their associated

pkgs/dart_mcp/lib/src/api/elicitation.dart

@@ -19,6 +19,7 @@ extension type ElicitRequest._fromMap(Map<String, Object?> _value)
   factory ElicitRequest({
     required String message,
     required ObjectSchema requestedSchema,
+    MetaWithProgressToken? meta,
   }) {
     assert(
       validateRequestedSchema(requestedSchema),
@@ -28,6 +29,7 @@ extension type ElicitRequest._fromMap(Map<String, Object?> _value)
       Keys.mode: ElicitationMode.form.name,
       Keys.message: message,
       Keys.requestedSchema: requestedSchema,
+      if (meta != null) Keys.meta: meta,
     });
   }
 
@@ -36,12 +38,14 @@ extension type ElicitRequest._fromMap(Map<String, Object?> _value)
     required String message,
     required String url,
     required String elicitationId,
+    MetaWithProgressToken? meta,
   }) {
     return ElicitRequest._fromMap({
       Keys.mode: ElicitationMode.url.name,
       Keys.message: message,
       Keys.url: url,
       Keys.elicitationId: elicitationId,
+      if (meta != null) Keys.meta: meta,
     });
   }
 

pkgs/dart_mcp/pubspec.yaml

@@ -1,5 +1,5 @@
 name: dart_mcp
-version: 0.5.0-wip
+version: 0.5.0
 description: A package for making MCP servers and clients.
 repository: https://github.com/dart-lang/ai/tree/main/pkgs/dart_mcp
 issue_tracker: https://github.com/dart-lang/ai/issues?q=is%3Aissue+is%3Aopen+label%3Apackage%3Adart_mcp

pkgs/dart_mcp_server/lib/src/mixins/grep_packages.dart

@@ -49,7 +49,8 @@ base mixin GrepSupport
     }
 
     final ripGrepExecutable =
-        await _checkForRipGrep() ?? await tryInstallRipGrep();
+        await _checkForRipGrep() ??
+        await tryInstallRipGrep(progressToken: request.meta?.progressToken);
     if (ripGrepExecutable == null) {
       return CallToolResult(
         content: [
@@ -202,15 +203,26 @@ base mixin GrepSupport
   ///
   /// [installDir] is the directory to install ripgrep to. If null, the default
   /// install directory will be used.
+  ///
+  /// If [progressToken] is passed, it will be added to the [ElicitRequest]
+  /// metadata. This is primarily used to forward on progress tokens, which is
+  /// required by some clients (it links the elicitation to a tool call).
   @visibleForTesting
-  Future<String?> tryInstallRipGrep({Directory? installDir}) async {
+  Future<String?> tryInstallRipGrep({
+    Directory? installDir,
+    ProgressToken? progressToken,
+  }) async {
     // If the client does not support elicitation, we cannot install ripgrep
     // because we can't get consent.
     if (clientCapabilities.elicitation == null) return null;
+    final meta = progressToken != null
+        ? MetaWithProgressToken(progressToken: progressToken)
+        : null;
     final elicitResult = await elicit(
       ElicitRequest.form(
         message: 'Ripgrep is required to run this tool, can I install it?',
         requestedSchema: Schema.object(),
+        meta: meta,
       ),
     );
     // The user did not approve the installation.