Aiden
Aiden
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CDCloudflare Developers
Created by Aiden on 2/25/2025 in #workers-help
workers-mcp: returning other types
Hi there! Has anyone else used the workers-mcp package? It works great, but I can't seem to return any data to the client except text. This might be a misunderstanding of MCP, but I'm curious if anyone else has thoughts. For example: 
  /**
   * Fetches the Message Data Model (MDM) for a given canonical ID.
   * @param canonicalId {string} The canonical ID to look up.
   * @return {object|string} The Message Data Model data or an error message.
   */
  /**
   * Fetches the Message Data Model (MDM) for a given canonical ID.
   * @param canonicalId {string} The canonical ID to look up.
   * @return {object|string} The Message Data Model data or an error message.
   */
Attempting to return an object to the client (in this case MCP Inspector) results in an "invalid tool result" error, even though the tool returns a valid JSON blob. I'm not sure how to return JSON to the client unless everything's just supposed to be handled as strings?
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