fix: address 2025-11-25 conformance audit findings (#951)

* fix: interpret task ttl as milliseconds

* fix: use text/plain for default text mime type

* fix: include resource param in token refresh

* test: align conformance prompt args with runner

* ci: run server conformance suite on PRs

* ci: build client bin and gate pending scenarios

Author: DaleSeo

.github/workflows/conformance.yml

@@ -0,0 +1,77 @@
+name: Conformance
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+  workflow_dispatch:
+
+concurrency:
+  group: conformance-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  # Pinned for reproducible runs; bump deliberately when the suite updates.
+  CONFORMANCE_VERSION: "0.1.16"
+
+jobs:
+  server:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@v7
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+
+      - uses: Swatinem/rust-cache@v2
+
+      # Build the whole package (server + client bins): the conformance crate is
+      # excluded from the workspace default-members, so this is the only CI job
+      # that catches compile breakage in it.
+      - name: Build conformance binaries
+        run: cargo build -p mcp-conformance
+
+      - name: Start conformance server
+        run: |
+          PORT=8001 ./target/debug/conformance-server &
+          echo $! > server.pid
+          for _ in $(seq 1 30); do
+            if curl -s -o /dev/null http://127.0.0.1:8001/mcp; then
+              exit 0
+            fi
+            sleep 1
+          done
+          echo "conformance server did not become ready" >&2
+          exit 1
+
+      - name: Run server conformance suite
+        run: |
+          npx -y "@modelcontextprotocol/conformance@${CONFORMANCE_VERSION}" server \
+            --url http://127.0.0.1:8001/mcp \
+            --spec-version 2025-11-25 \
+            -o conformance-results
+
+      # These pass today but are excluded from the default "active" suite;
+      # run them explicitly so regressions are still caught.
+      - name: Run pending scenarios
+        run: |
+          for scenario in json-schema-2020-12 server-sse-polling; do
+            npx -y "@modelcontextprotocol/conformance@${CONFORMANCE_VERSION}" server \
+              --url http://127.0.0.1:8001/mcp \
+              --scenario "$scenario" \
+              -o conformance-results
+          done
+
+      - name: Stop conformance server
+        if: always()
+        run: kill "$(cat server.pid)" 2>/dev/null || true
+
+      - name: Upload results
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: conformance-server-results
+          path: conformance-results

conformance/src/bin/server.rs

@@ -656,11 +656,11 @@ impl ServerHandler for ConformanceServer {
                     "test_prompt_with_arguments",
                     Some("A test prompt that accepts arguments"),
                     Some(vec![
-                        PromptArgument::new("name")
-                            .with_description("The name to greet")
+                        PromptArgument::new("arg1")
+                            .with_description("First test argument")
                             .with_required(true),
-                        PromptArgument::new("style")
-                            .with_description("The greeting style")
+                        PromptArgument::new("arg2")
+                            .with_description("Second test argument")
                             .with_required(false),
                     ]),
                 ),
@@ -692,14 +692,11 @@ impl ServerHandler for ConformanceServer {
             .with_description("A simple test prompt")),
             "test_prompt_with_arguments" => {
                 let args = request.arguments.unwrap_or_default();
-                let name = args.get("name").and_then(|v| v.as_str()).unwrap_or("World");
-                let style = args
-                    .get("style")
-                    .and_then(|v| v.as_str())
-                    .unwrap_or("friendly");
+                let arg1 = args.get("arg1").and_then(|v| v.as_str()).unwrap_or("");
+                let arg2 = args.get("arg2").and_then(|v| v.as_str()).unwrap_or("");
                 Ok(GetPromptResult::new(vec![PromptMessage::new_text(
                     Role::User,
-                    format!("Please greet {} in a {} style.", name, style),
+                    format!("Prompt with arguments: arg1='{}', arg2='{}'", arg1, arg2),
                 )])
                 .with_description("A prompt with arguments"))
             }

crates/rmcp/src/model/content.rs

@@ -297,7 +297,7 @@ impl ContentBlock {
         ContentBlock::Resource(EmbeddedResource::new(
             ResourceContents::TextResourceContents {
                 uri: uri.into(),
-                mime_type: Some("text".to_string()),
+                mime_type: Some("text/plain".to_string()),
                 text: content.into(),
                 meta: None,
             },

crates/rmcp/src/model/resource.rs

@@ -193,7 +193,7 @@ impl ResourceContents {
     pub fn text(text: impl Into<String>, uri: impl Into<String>) -> Self {
         Self::TextResourceContents {
             uri: uri.into(),
-            mime_type: Some("text".into()),
+            mime_type: Some("text/plain".into()),
             text: text.into(),
             meta: None,
         }

crates/rmcp/src/task_manager.rs

@@ -49,6 +49,7 @@ impl OperationDescriptor {
         self
     }
 
+    /// Time-to-live in milliseconds, matching `TaskMetadata.ttl` from the MCP spec.
     pub fn with_ttl(mut self, ttl: u64) -> Self {
         self.ttl = Some(ttl);
         self
@@ -75,7 +76,11 @@ pub trait OperationResultTransport: Send + Sync + 'static {
 }
 
 // ===== Operation Processor =====
-pub const DEFAULT_TASK_TIMEOUT_SECS: u64 = 300; // 5 minutes
+#[deprecated(note = "use DEFAULT_TASK_TIMEOUT_MS; ttl values are milliseconds per the MCP spec")]
+pub const DEFAULT_TASK_TIMEOUT_SECS: u64 = 300;
+/// Default execution timeout (5 minutes), in milliseconds, applied when a
+/// descriptor does not specify a `ttl`.
+pub const DEFAULT_TASK_TIMEOUT_MS: u64 = 300_000;
 /// Operation processor that coordinates extractors and handlers
 pub struct OperationProcessor {
     /// Currently running tasks keyed by id
@@ -165,13 +170,13 @@ impl OperationProcessor {
     fn spawn_async_task(&mut self, message: OperationMessage) {
         let OperationMessage { descriptor, future } = message;
         let task_id = descriptor.operation_id.clone();
-        let timeout_secs = descriptor.ttl.or(Some(DEFAULT_TASK_TIMEOUT_SECS));
+        let timeout_ms = descriptor.ttl.or(Some(DEFAULT_TASK_TIMEOUT_MS));
         let sender = self.task_result_sender.clone();
         let descriptor_for_result = descriptor.clone();
 
         let timed_future = async move {
-            if let Some(secs) = timeout_secs {
-                match timeout(Duration::from_secs(secs), future).await {
+            if let Some(ms) = timeout_ms {
+                match timeout(Duration::from_millis(ms), future).await {
                     Ok(result) => result,
                     Err(_) => Err(Error::TaskError("Operation timed out".to_string())),
                 }
@@ -191,7 +196,7 @@ impl OperationProcessor {
         let running_task = RunningTask {
             task_handle: handle,
             started_at: std::time::Instant::now(),
-            timeout: timeout_secs,
+            timeout: timeout_ms,
             descriptor,
         };
         self.running_tasks.insert(task_id, running_task);
@@ -213,7 +218,7 @@ impl OperationProcessor {
 
         for (task_id, task) in &self.running_tasks {
             if let Some(timeout_duration) = task.timeout {
-                if now.duration_since(task.started_at).as_secs() > timeout_duration {
+                if now.duration_since(task.started_at).as_millis() > u128::from(timeout_duration) {
                     task.task_handle.abort();
                     timed_out_tasks.push(task_id.clone());
                 }

crates/rmcp/src/transport/auth.rs

@@ -1687,7 +1687,10 @@ impl AuthorizationManager {
         debug!("refresh token present, attempting refresh");
 
         let refresh_token_value = RefreshToken::new(refresh_token.secret().to_string());
-        let mut refresh_request = oauth_client.exchange_refresh_token(&refresh_token_value);
+        let mut refresh_request = oauth_client
+            .exchange_refresh_token(&refresh_token_value)
+            // RFC 8707: the resource indicator is required on token requests, including refreshes
+            .add_extra_param("resource", self.base_url.to_string());
         let mut refresh_scopes = stored_credentials.granted_scopes;
         self.add_offline_access_if_supported(&mut refresh_scopes);
         for scope in refresh_scopes {
@@ -5489,6 +5492,42 @@ mod tests {
         assert_eq!(scope_parts, vec!["read", "write"]);
     }
 
+    #[tokio::test]
+    async fn refresh_token_includes_resource_parameter() {
+        let (base_url, captured) = start_token_server().await;
+
+        let mut manager = manager_with_metadata(Some(AuthorizationMetadata {
+            authorization_endpoint: format!("{}/authorize", base_url),
+            token_endpoint: format!("{}/token", base_url),
+            ..Default::default()
+        }))
+        .await;
+        manager.configure_client(test_client_config()).unwrap();
+
+        let stored = StoredCredentials {
+            client_id: "my-client".to_string(),
+            token_response: Some(make_token_response_with_refresh(
+                "old-token",
+                "my-refresh-token",
+            )),
+            granted_scopes: vec![],
+            token_received_at: Some(AuthorizationManager::now_epoch_secs()),
+        };
+        manager.credential_store.save(stored).await.unwrap();
+
+        manager.refresh_token().await.unwrap();
+
+        let body = captured.lock().unwrap().take().unwrap();
+        let params: std::collections::HashMap<_, _> = url::form_urlencoded::parse(body.as_bytes())
+            .into_owned()
+            .collect();
+        assert_eq!(
+            params.get("resource").map(String::as_str),
+            Some("http://localhost/"),
+            "refresh requests must carry the RFC 8707 resource parameter, got body: {body}"
+        );
+    }
+
     #[tokio::test]
     async fn refresh_token_adds_offline_access_when_as_supports_it() {
         let (base_url, captured) = start_token_server().await;

crates/rmcp/tests/test_task.rs

@@ -80,6 +80,38 @@ async fn rejects_duplicate_operation_ids() {
     assert!(format!("{err}").contains("already running"));
 }
 
+#[tokio::test]
+async fn ttl_is_interpreted_as_milliseconds() {
+    let mut processor = OperationProcessor::new();
+    let descriptor = OperationDescriptor::new("slow", "dummy").with_ttl(50);
+    let future = Box::pin(async {
+        tokio::time::sleep(Duration::from_millis(500)).await;
+        Ok(Box::new(DummyTransport {
+            id: "slow".to_string(),
+            value: 0,
+        }) as Box<dyn OperationResultTransport>)
+    });
+
+    processor
+        .submit_operation(OperationMessage::new(descriptor, future))
+        .expect("submit operation");
+
+    tokio::time::sleep(Duration::from_millis(200)).await;
+    let results = processor.peek_completed();
+    assert_eq!(
+        results.len(),
+        1,
+        "50ms ttl should have timed out the operation well within 200ms"
+    );
+    match &results[0].result {
+        Err(err) => assert!(
+            err.to_string().contains("timed out"),
+            "unexpected error: {err}"
+        ),
+        Ok(_) => panic!("expected the operation to time out, but it completed"),
+    }
+}
+
 #[test]
 fn task_status_notification_param_preserves_meta() {
     let raw = json!({