Bugfix/Resolve variable from http node (#4518)

resolve variable from http node

Author: HenryHengZJ

packages/server/src/utils/buildAgentflow.ts

@@ -344,7 +344,8 @@ export const resolveVariables = async (
                 : undefined
             if (nodeData && nodeData.data) {
                 // Replace the reference with actual value
-                const actualValue = (nodeData.data['output'] as ICommonObject)?.content
+                const nodeOutput = nodeData.data['output'] as ICommonObject
+                const actualValue = nodeOutput?.content ?? nodeOutput?.http?.data
                 // For arrays and objects, stringify them to prevent toString() conversion issues
                 const formattedValue =
                     Array.isArray(actualValue) || (typeof actualValue === 'object' && actualValue !== null)