Calendar MCP: The caller does not have permission

[daviddavo]

I'm trying to use Google Calendar's MCP by following this tutorial:

https://developers.google.com/workspace/calendar/api/guides/configure-mcp-server

But I when I try to use the MCP, I get the following error:

 > Can you please write the tool call and response?
✦ The tool call made was:

   1 mcp_calendar_list_events(endTime='2026-04-28T00:00:00', startTime='2026-04-27T00:00:00')

  And the response received was:

   1 {
   2     "error": "MCP tool 'list_events' reported tool error for function call: {\"name\":\"list_events\",\"args\":{\"endTime\":\"2026-04-28T00:00:00\",\"startTime\":\"2026-04-27T00:00:00\"}} with response:
     [{\"functionResponse\":{\"name\":\"list_events\",\"response\":{\"content\":[{\"type\":\"text\",\"text\":\"The caller does not have permission\"}],\"isError\":true}}}]"
   3 }

I already had a Google Cloud account and it is working in an n8n integration, I enabled the APIs and created a new oauth, logged in with /mcp auth but I get that error, why? How could I "debug" it?

[azoz-w]

Same here!

[gl-devis]

How to resolve this issue?

[osipov-anton]

How to resolve this issue?

[tuapuikia]

Are you a google workspace customer?

[daviddavo]

No, I'm not, that was the problem...

[gl-devis]

must be a google workspace customer?

[leoleoasd]

@tuapuikia I'm a google workspace customer and still seeing this issue

[molavec]

@tuapuikia I'm a google workspace customer and still seeing this issue

Same problem here. I double check this link:

https://developers.google.com/workspace/drive/api/guides/configure-mcp-server?hl=es-419

[shirish075]

SO finallly What to do . how to get rid off this error . should we buy something

[AspireOne]

I ended up having a LLM implement classic local function calling instead of using their mcp. Ugly ass code, but now it works for my usecase. https://github.com/AspireOne/scheduled_tasks src/calendar/

[sin325]

Hi Yuxuan, I hope you are doing well. Regarding the "Calendar MCP: The caller does not have permission" issue you reported, I have noted that you are still experiencing this error despite being a Google Workspace customer. I will look further into why this permission error is persisting for your account type. In the meantime, could you please provide [any specific error logs or screenshots] to help us investigate this further? Thank you,

…

On Tue, 9 Jun, 2026, 3:34 pm Yuxuan Lu, ***@***.***> wrote: @tuapuikia <https://github.com/tuapuikia> I'm a google workspace customer and still seeing this issue — Reply to this email directly, view it on GitHub <#26017?email_source=notifications&email_token=ASRK757ERGTRHKXWQEZUBU34664ZFA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCNZSGMZDSNBVUZZGKYLTN5XKU43VMJZWG4TJMJSWJJLFOZSW45FMMZXW65DFOJPWG3DJMNVQ#discussioncomment-17232945>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ASRK757VO2WF5GQSUSVUUXL4664ZFAVCNFSM6AAAAACYHDFKUCVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTOMRTGI4TINI> . You are receiving this because you are subscribed to this thread.Message ID: <google-gemini/gemini-cli/repo-discussions/26017/comments/17232945@ github.com>

[leoleoasd]

are you a google employee?

[kansaizine]

same issue on Claude Desktop on 3P.
all Google Workspace MCPs (Gmail, Drive, etc) are returns "The caller does not have permission" error.

[steventine]

I had this same problem, then I discovered that the MCPs are currently listed under Developer Preview. I submitted the application form to join the the Google Workspace Developer Preview Program and was approved quickly. After that, the MCP started working.

[kansaizine]

Thank you for the information.
I will try it.