From 2ce0cc398ce427120dc3f80ac0766470ecbed981 Mon Sep 17 00:00:00 2001
From: jaaacki <jacki.da@gmail.com>
Date: Thu, 6 Aug 2026 23:40:06 +0800
Subject: [PATCH] fix(mcp): honour deferred flag from transport_config

Every MCP server was constructed with deferred: Some(false), so no tool was
ever marked deferred. ToolSearch filters tool_defs on .filter(|d| d.deferred),
so it always matched an empty set and returned "No deferred tools matching"
regardless of query, tool count, or how the server was installed.

aionrs supports the flag per server (McpServerConfig::deferred, defaulting to
true when omitted) and registers ToolSearchTool unconditionally, so the feature
was reachable in the engine but never enabled by the host.

Read the flag from the same transport_config JSON that command/args/env/url/
headers already come from. An absent key still yields false, so existing
behaviour is unchanged; an explicit true opts a server in.

Scoped to row_to_mcp_server_config (DB-configured servers). Session-scoped and
internal team servers are left as-is.

Refs #793
---
 crates/aionui-ai-agent/src/factory/aionrs.rs | 39 ++++++++++++++++++--
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/crates/aionui-ai-agent/src/factory/aionrs.rs b/crates/aionui-ai-agent/src/factory/aionrs.rs
index da9fba085..8ac62efb6 100644
--- a/crates/aionui-ai-agent/src/factory/aionrs.rs
+++ b/crates/aionui-ai-agent/src/factory/aionrs.rs
@@ -501,6 +501,11 @@ async fn row_to_mcp_server_config(
     let value: serde_json::Value =
         serde_json::from_str(&row.transport_config).map_err(|e| format!("invalid transport_config JSON: {e}"))?;
 
+    // Whether this server's tools are sent to the LLM as name-only stubs, to be
+    // loaded on demand via ToolSearch. Absent key preserves the previous
+    // behaviour (all schemas eager); an explicit `true` opts the server in.
+    let deferred = value.get("deferred").and_then(|v| v.as_bool()).unwrap_or(false);
+
     match row.transport_type.as_str() {
         "stdio" => {
             let command = value
@@ -531,7 +536,7 @@ async fn row_to_mcp_server_config(
                 env: Some(env),
                 url: None,
                 headers: None,
-                deferred: Some(false),
+                deferred: Some(deferred),
                 startup_timeout_ms: None,
             })
         }
@@ -557,7 +562,7 @@ async fn row_to_mcp_server_config(
                 env: None,
                 url: Some(url.to_owned()),
                 headers: Some(headers),
-                deferred: Some(false),
+                deferred: Some(deferred),
                 startup_timeout_ms: None,
             })
         }
@@ -583,7 +588,7 @@ async fn row_to_mcp_server_config(
                 env: None,
                 url: Some(url.to_owned()),
                 headers: Some(headers),
-                deferred: Some(false),
+                deferred: Some(deferred),
                 startup_timeout_ms: None,
             })
         }
@@ -1018,6 +1023,34 @@ mod tests {
         );
     }
 
+    #[tokio::test]
+    async fn row_to_mcp_server_config_defaults_deferred_to_false() {
+        let row = make_row("docs", "http", r#"{"url":"https://example.test/mcp"}"#, true, false);
+
+        let config = row_to_mcp_server_config(&row, "user-row", "conv-row", test_broadcaster())
+            .await
+            .expect("convert");
+
+        assert_eq!(config.deferred, Some(false));
+    }
+
+    #[tokio::test]
+    async fn row_to_mcp_server_config_honours_explicit_deferred() {
+        let row = make_row(
+            "docs",
+            "http",
+            r#"{"url":"https://example.test/mcp","deferred":true}"#,
+            true,
+            false,
+        );
+
+        let config = row_to_mcp_server_config(&row, "user-row", "conv-row", test_broadcaster())
+            .await
+            .expect("convert");
+
+        assert_eq!(config.deferred, Some(true));
+    }
+
     struct ProviderMappingCase<'a> {
         name: &'a str,
         platform: &'a str,