fix: correct AgentExecutorBlock handle IDs to match link sink_names

- CustomNode: Use inputs_#_<field> format for AGENT block handles
  to match standard dictionary input pattern and link sink_names
- core.py: Wrap UUID lookup in try/except for graceful degradation

autogpt_platform/backend/backend/api/features/chat/tools/agent_generator/core.py

@@ -336,7 +336,14 @@ async def get_all_relevant_agents_for_generation(
         for graph_id in mentioned_uuids:
             if graph_id == exclude_graph_id:
                 continue
-            agent = await get_library_agent_by_graph_id(user_id, graph_id)
+            try:
+                agent = await get_library_agent_by_graph_id(user_id, graph_id)
+            except Exception as e:
+                logger.warning(
+                    f"Failed to fetch explicitly mentioned agent {graph_id}: {e}",
+                    exc_info=True,
+                )
+                continue
             agent_graph_id = agent.get("graph_id") if agent else None
             if agent and agent_graph_id and agent_graph_id not in seen_graph_ids:
                 agents.append(agent)

autogpt_platform/frontend/src/app/(platform)/build/components/legacy-builder/CustomNode/CustomNode.tsx

@@ -528,6 +528,10 @@ export const CustomNode = React.memo(
           const getInputPropKey = (key: string) =>
             nodeType == BlockUIType.AGENT ? `inputs.${key}` : key;
 
+          // For AGENT blocks, handle IDs need the inputs_#_ prefix to match link sink_names
+          const getHandleKey = (key: string) =>
+            nodeType == BlockUIType.AGENT ? `inputs_#_${key}` : key;
+
           return keys.map(([propKey, propSchema]) => {
             const isRequired = data.inputSchema.required?.includes(propKey);
             const isAdvanced = propSchema.advanced;
@@ -544,7 +548,8 @@ export const CustomNode = React.memo(
               !propKey.endsWith("_credentials") &&
               // For OUTPUT blocks, only show the 'value' (hides 'name') input connection handle
               !(nodeType == BlockUIType.OUTPUT && propKey == "name");
-            const isConnected = isInputHandleConnected(propKey);
+            const handleKey = getHandleKey(propKey);
+            const isConnected = isInputHandleConnected(handleKey);
 
             return (
               !isHidden &&
@@ -562,12 +567,12 @@ export const CustomNode = React.memo(
                     propSchema.discriminator
                   ) ? (
                     <NodeHandle
-                      keyName={propKey}
+                      keyName={handleKey}
                       isConnected={isConnected}
                       isRequired={isRequired}
                       schema={propSchema}
                       side="left"
-                      isBroken={isInputHandleBroken(propKey)}
+                      isBroken={isInputHandleBroken(handleKey)}
                     />
                   ) : (
                     propKey !== "credentials" &&