Can't access auth when calling an agent from MCP

Hello, I am facing a problem happy to get your help! 🙂 Working with express, I have created the following MCP

export const startMcp = async (app: INestApplication) => {
  const mastraService = app.get(MastraService, { strict: false });
  const organizationService = app.get(OrganizationService, { strict: false });

  const mastra = await mastraService.mastra();
  const agent = mastra.getAgent('postiz');
  const tools = await agent.getTools();

  const server = new MCPServer({
    name: 'Postiz MCP',
    version: '1.0.0',
    tools,
    agents: { postiz: agent },
  });

  app.use(
    '/mcp/:id',
    async (req: Request, res: Response, next: NextFunction) => {
      if (req.method === 'OPTIONS') {
        res.sendStatus(200);
        return;
      }

      // @ts-ignore
      req.auth = await organizationService.getOrgByApiKey(req.params.id);
      // @ts-ignore
      if (!req.auth) {
        throw new HttpException('Invalid url', 400);
      }

      const url = new URL(
        `/mcp/${req.params.id}`,
        process.env.NEXT_PUBLIC_BACKEND_URL
      );
      await server.startHTTP({
        url,
        httpPath: url.pathname,
        options: {
          sessionIdGenerator: () => {
            return randomUUID();
          },
        },
        req,
        res,
      });
    }
  );
};

export const startMcp = async (app: INestApplication) => {
  const mastraService = app.get(MastraService, { strict: false });
  const organizationService = app.get(OrganizationService, { strict: false });

  const mastra = await mastraService.mastra();
  const agent = mastra.getAgent('postiz');
  const tools = await agent.getTools();

  const server = new MCPServer({
    name: 'Postiz MCP',
    version: '1.0.0',
    tools,
    agents: { postiz: agent },
  });

  app.use(
    '/mcp/:id',
    async (req: Request, res: Response, next: NextFunction) => {
      if (req.method === 'OPTIONS') {
        res.sendStatus(200);
        return;
      }

      // @ts-ignore
      req.auth = await organizationService.getOrgByApiKey(req.params.id);
      // @ts-ignore
      if (!req.auth) {
        throw new HttpException('Invalid url', 400);
      }

      const url = new URL(
        `/mcp/${req.params.id}`,
        process.env.NEXT_PUBLIC_BACKEND_URL
      );
      await server.startHTTP({
        url,
        httpPath: url.pathname,
        options: {
          sessionIdGenerator: () => {
            return randomUUID();
          },
        },
        req,
        res,
      });
    }
  );
};

The req.auth works great in tools, I have been doing something like this:

  // @ts-ignore
  if (options?.extra?.authInfo) {
    // @ts-ignore
    runtimeContext.set('organization', JSON.stringify(options.extra.authInfo));
  }

  // @ts-ignore
  if (options?.extra?.authInfo) {
    // @ts-ignore
    runtimeContext.set('organization', JSON.stringify(options.extra.authInfo));
  }

Here is where I face a problem / bug. I am using the MCP inspector from Anthropic. When I execute a tool, it works great with options?.extra?.authInfo. But if I send a question to my agent "ask_postiz", I don't get the options?.extra?.authInfo in the tool anymore. Are there any extra steps I am missing?

9 Replies

Nevo DavidOP•6d ago

I ended up using AsyncStorage for now waiting for a response 🙂

_roamin_•6d ago

Hey @Daniel Lew ! Is that something that's possible currently?

Mastra Triager•5d ago

📝 Created GitHub issue: https://github.com/mastra-ai/mastra/issues/8948

GitHub

[DISCORD:1428353801869332650] Can't access auth when calling an age...

This issue was created from Discord post: https://discord.com/channels/1309558646228779139/1428353801869332650 Hello, I am facing a problem happy to get your help! 🙂 Working with express, I have cr...

Daniel Lew•5d ago

hmm if I understand correctly, when you use the MCPClient and pull the tool off of the MCPServer to pass to the agent, the req.auth does not get set, is that right?

Nevo DavidOP•5d ago

Yup

Daniel Lew•5d ago

is your MCP route '/mcp/:id' getting hit when the agent executes the tool?

Nevo DavidOP•5d ago

Yes, all the other tools get the auth, only the ask<agent> after passing to the tool is not passing so for example: execute >> tool >> there is auth execute >> tool (ask<name>) - which is the agent >> tool - no auth

Daniel Lew•5d ago

ooh! Now I understand, when you convert the agent to a tool it doesn't work as expected. I'm getting there is probably just some context not being passed to the agent when we convert it into a tool

Nevo DavidOP•5d ago

Does it supposed to pass the auth, or it's not how it should work? 🙂

Gaming

Programming

Can't access auth when calling an agent from MCP

Did you find this page helpful?