Claude.ai custom MCP connector fails after successful Activepieces authorization

Hi Activepieces team,

I’m trying to connect Claude.ai to Activepieces Cloud using the custom remote MCP connector URL:

https://cloud.activepieces.com/mcp

What happens:

1. I add the custom connector in Claude successfully.

2. I click Connect.

3. The Activepieces authorization page opens correctly.

4. I select the correct project: HAFIS’s Project.

5. Activepieces reports success / connected.

6. But after returning to Claude, Claude still fails with:

“Authorization with the MCP server failed. You can check your credentials and permissions.”

This reproduces on both mobile and desktop.

Important context:

- The Activepieces MCP server is enabled in the project.

- The relevant flows are exposed in MCP Server > Tools > Your Flows.

- The custom connector URL is:

https://cloud.activepieces.com/mcp

- Browser access to that URL returns the expected response:

“Use POST with Authorization: Bearer for MCP requests.”

so the endpoint appears alive.

Anthropic support suggested likely causes may include:

- callback URL allowlist mismatch

- scope / permission mismatch after OAuth

- auth state propagation mismatch between Claude and Activepieces

Could you please confirm:

1. whether Activepieces Cloud MCP fully supports Claude.ai web custom connectors

2. whether both claude.ai and claude.com callback URLs are allowlisted if needed

3. whether the OAuth/token/scopes returned by Activepieces match Claude’s expected MCP connector flow

4. whether this is a known compatibility issue with Claude.ai web custom connectors

Anthropic-side reference IDs:

- 0fld_534082ccfb138e71

- 0fld_5d91a4bfa0c0c1e2

- 0fld_4d639c01d4447d46

- 0fld_4292b72a9ad8eca5

If needed, I can provide screenshots of the Claude error banner, the successful Activepieces authorization screen, and the Claude connector entry state.

Thanks.