Problem summary
You connected Funnel MCP and completed OAuth sign-in without errors, but every tool call fails with a token exchange authentication error.
Error message or symptoms
{"error": "token_exchange_failed", "message": "Authentication failed. Please try again."}
OAuth can complete without errors, but simple tool calls such as list_workspaces fail immediately afterward.
When does this occur
After you connect Funnel MCP in an MCP client and complete the OAuth sign-in flow
When any Funnel MCP tool call fails right away, including calls that do not use workspace-specific parameters
In MCP clients such as Claude Code, Claude desktop or other MCP-compatible tools
Root cause
Funnel could not finish authentication after your MCP client obtained OAuth approval. Two common causes:
Wrong regional MCP server URL: Your client is using an MCP endpoint that does not match your Funnel subscription region.
MCP access not fully enabled on your account: For some accounts, MCP may not be fully configured.
Solution
Confirm your Remote MCP server URL matches your Funnel region:
Global (default):
https://mcp.ai.funnel.io/mcpEU:
https://mcp.eu.ai.funnel.io/mcp
Copy Server URL from Connect Funnel MCP in Funnel AI full view (Data > Analyze > Funnel AI) if you are unsure which URL to use.
If the URL was wrong, update it in your MCP client. Remove the Funnel connector, add it again with the correct URL and complete OAuth again.
If the URL is already correct, disconnect and reconnect the Funnel MCP integration once, then try a simple tool call in a new chat or session (for example
List the workspaces I can access in Funnel.).
If you still see
token_exchange_failed, contact Funnel support. Include the full error text and the approximate time of your last failed attempt.
When Funnel support confirms your account is updated, reconnect if needed and run your verification prompt again in a new chat or session.