fix(gateway): preserve structured tool results

.github/workflows/ci.yml

@@ -17,6 +17,7 @@ permissions:
   actions: read
   checks: write
   pull-requests: write
+  id-token: write
 
 env:
   CARGO_TERM_COLOR: always

.github/workflows/claude-code-review.yml

@@ -0,0 +1,44 @@
+name: Claude Code Review
+
+on:
+  pull_request:
+    types: [opened, synchronize, ready_for_review, reopened]
+    # Optional: Only run on specific file changes
+    # paths:
+    #   - "src/**/*.ts"
+    #   - "src/**/*.tsx"
+    #   - "src/**/*.js"
+    #   - "src/**/*.jsx"
+
+jobs:
+  claude-review:
+    # Optional: Filter by PR author
+    # if: |
+    #   github.event.pull_request.user.login == 'external-contributor' ||
+    #   github.event.pull_request.user.login == 'new-developer' ||
+    #   github.event.pull_request.author_association == 'FIRST_TIME_CONTRIBUTOR'
+
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: read
+      issues: read
+      id-token: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Run Claude Code Review
+        id: claude-review
+        uses: anthropics/claude-code-action@v1
+        with:
+          claude_code_oauth_token: ${{ secrets.CLAUDE_CODE_OAUTH_TOKEN }}
+          plugin_marketplaces: 'https://github.com/anthropics/claude-code.git'
+          plugins: 'code-review@claude-code-plugins'
+          prompt: '/code-review:code-review ${{ github.repository }}/pull/${{ github.event.pull_request.number }}'
+          # See https://github.com/anthropics/claude-code-action/blob/main/docs/usage.md
+          # or https://code.claude.com/docs/en/cli-reference for available options
+

.github/workflows/claude.yml

@@ -0,0 +1,50 @@
+name: Claude Code
+
+on:
+  issue_comment:
+    types: [created]
+  pull_request_review_comment:
+    types: [created]
+  issues:
+    types: [opened, assigned]
+  pull_request_review:
+    types: [submitted]
+
+jobs:
+  claude:
+    if: |
+      (github.event_name == 'issue_comment' && contains(github.event.comment.body, '@claude')) ||
+      (github.event_name == 'pull_request_review_comment' && contains(github.event.comment.body, '@claude')) ||
+      (github.event_name == 'pull_request_review' && contains(github.event.review.body, '@claude')) ||
+      (github.event_name == 'issues' && (contains(github.event.issue.body, '@claude') || contains(github.event.issue.title, '@claude')))
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: read
+      issues: read
+      id-token: write
+      actions: read # Required for Claude to read CI results on PRs
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Run Claude Code
+        id: claude
+        uses: anthropics/claude-code-action@v1
+        with:
+          claude_code_oauth_token: ${{ secrets.CLAUDE_CODE_OAUTH_TOKEN }}
+
+          # This is an optional setting that allows Claude to read CI results on PRs
+          additional_permissions: |
+            actions: read
+
+          # Optional: Give a custom prompt to Claude. If this is not specified, Claude will perform the instructions specified in the comment that tagged it.
+          # prompt: 'Update the pull request description to include a summary of changes.'
+
+          # Optional: Add claude_args to customize behavior and configuration
+          # See https://github.com/anthropics/claude-code-action/blob/main/docs/usage.md
+          # or https://code.claude.com/docs/en/cli-reference for available options
+          # claude_args: '--allowed-tools Bash(gh pr *)'
+

crates/mcpmux-gateway/src/mcp/handler.rs

@@ -860,15 +860,13 @@ impl ServerHandler for McpMuxGatewayHandler {
             .await
             .map_err(|e| McpError::internal_error(format!("Tool call failed: {}", e), None))?;
 
-        // Convert ToolCallResult to MCP CallToolResult
-        let content: Vec<Content> = tool_result
-            .content
-            .into_iter()
-            .filter_map(|v| serde_json::from_value(v).ok())
-            .collect();
+        // Convert ToolCallResult to MCP CallToolResult without dropping
+        // structuredContent or protocol-level _meta from the upstream server.
+        let result = tool_result.into_mcp_result();
 
         // Log result summary - show content types and approximate sizes
-        let content_summary: Vec<String> = content
+        let content_summary: Vec<String> = result
+            .content
             .iter()
             .map(|c| {
                 // Content is Annotated<RawContent>, serialize to inspect type
@@ -907,17 +905,11 @@ impl ServerHandler for McpMuxGatewayHandler {
             .collect();
         debug!(
             tool = %params.name,
-            is_error = tool_result.is_error,
+            is_error = result.is_error.unwrap_or(false),
             content = ?content_summary,
             "call_tool result"
         );
 
-        let result = if tool_result.is_error {
-            CallToolResult::error(content)
-        } else {
-            CallToolResult::success(content)
-        };
-
         Ok(result)
     }
 

crates/mcpmux-gateway/src/pool/routing.rs

@@ -12,7 +12,7 @@ use std::time::Duration;
 
 use anyhow::{anyhow, Result};
 use mcpmux_core::{FeatureType, LogLevel, LogSource, ServerLog, ServerLogManager};
-use rmcp::model::CallToolRequestParams;
+use rmcp::model::{CallToolRequestParams, CallToolResult, Content, Meta};
 use serde_json::Value;
 use tracing::{debug, info, warn};
 use uuid::Uuid;
@@ -52,6 +52,39 @@ pub struct RoutedResource {
 pub struct ToolCallResult {
     pub content: Vec<Value>,
     pub is_error: bool,
+    pub structured_content: Option<Value>,
+    pub meta: Option<Meta>,
+}
+
+impl ToolCallResult {
+    fn from_mcp_result(result: CallToolResult) -> Self {
+        Self {
+            content: result
+                .content
+                .into_iter()
+                .map(|item| serde_json::to_value(item).unwrap_or(Value::Null))
+                .collect(),
+            is_error: result.is_error.unwrap_or(false),
+            structured_content: result.structured_content,
+            meta: result.meta,
+        }
+    }
+
+    pub(crate) fn into_mcp_result(self) -> CallToolResult {
+        let content: Vec<Content> = self
+            .content
+            .into_iter()
+            .filter_map(|item| serde_json::from_value(item).ok())
+            .collect();
+        let mut result = if self.is_error {
+            CallToolResult::error(content)
+        } else {
+            CallToolResult::success(content)
+        };
+        result.structured_content = self.structured_content;
+        result.meta = self.meta;
+        result
+    }
 }
 
 /// Default timeout for MCP tool calls (60 seconds)
@@ -284,16 +317,7 @@ impl RoutingService {
                         .map_err(|_| anyhow!("Tool call timed out after {:?}", TOOL_CALL_TIMEOUT))?
                         .map_err(|e| anyhow!("MCP call failed: {}", e))?;
 
-                    let content: Vec<Value> = res
-                        .content
-                        .into_iter()
-                        .map(|c| serde_json::to_value(c).unwrap_or(Value::Null))
-                        .collect();
-
-                    Ok(ToolCallResult {
-                        content,
-                        is_error: res.is_error.unwrap_or(false),
-                    })
+                    Ok(ToolCallResult::from_mcp_result(res))
                 }
                 None => Err(anyhow!("Server instance has no active client")),
             }
@@ -726,3 +750,29 @@ impl RoutingService {
         false
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::ToolCallResult;
+    use rmcp::model::{CallToolResult, Content, Meta};
+    use serde_json::json;
+
+    #[test]
+    fn tool_result_round_trip_preserves_structured_content_and_meta() {
+        let structured = json!({ "matches": [{ "message": "found" }] });
+        let mut meta = Meta::new();
+        meta.0.insert("traceId".to_string(), json!("trace-123"));
+
+        let mut upstream = CallToolResult::structured(structured.clone());
+        upstream.content = vec![Content::text("search completed")];
+        upstream.meta = Some(meta.clone());
+
+        let routed = ToolCallResult::from_mcp_result(upstream);
+        let forwarded = routed.into_mcp_result();
+
+        assert_eq!(forwarded.content, vec![Content::text("search completed")]);
+        assert_eq!(forwarded.structured_content, Some(structured));
+        assert_eq!(forwarded.meta, Some(meta));
+        assert_eq!(forwarded.is_error, Some(false));
+    }
+}