I’m trying to connect to the Canva MCP server in n8n, but I keep getting the error:
“Could not connect to your MCP server. Authentication failed.”
This happens when I try to execute the node. Even though I successfully connected my credentials and received confirmation that the account was connected, the error still there.
Also, when I exit the credentials window and reopen it and try to reconnect, I get an error saying “client secret is invalid.” as if my client secret (token) is not being saved.
Can you help me plzz ?
Hi @selssabil_27 Welcome!
For that client secret disappearing is basically a UI element to protect it, maybe if you are using the right URL is worth checking:
authorization URL: https://www.canva.com/api/oauth/authorize
access token URL: https://api.canva.com/rest/v1/oauth/token
once done, confirm that your n8n’s redirect URL is configured on the canva dev platform, i suppose you are not using the LOCALHOST one as this is what majorly causes MCPs to fail connection, maybe strict HTTP requests would be a good thing to try if MCP does not work at all.
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Hi @Anshul_Namdev, so my URLs are correct - authorization URL and access token urls - , and yes my n8n’s redirect URL is configured on canva dev platform, and yes i am not using LOCALHOST. iam still getting the same error 
Um.. First i want you to check how you have settled up your credentials just crosscheck with this:
Umm maybe you can try reauthenticating basically try to revoke your credentials and use the new one, and if the canva use HTTP Streamable connections you gotta switch over that in your HTTP node, although connecting to Canva API seems to be very easy but MCP is a little rough.
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ive run into this before when n8n’s oauth handler doesn’t parse the token response correctly — the credential window showing success but then 403 on reconnect usually means the access_token wasn’t actually stored. iirc n8n expects a standard access_token field from the token endpoint, so check if canva returns that or something custom. if its still broken, falling back to the raw http request node with generic oauth2 can help narrow down whether its n8n’s mcp handler or canva’s side.
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welcome to the n8n community @selssabil_27
This looks like it might be a bug. It would be worth opening a GitHub issue with a minimal test case and the required details from the issue template.
Issues · n8n-io/n8n
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