🐞 Creating pages (in a DB): API works but when using MCP tool, getting strange error

[andrewconnell]

When using the MCP integration with Claude, I'm unable to create a page... when inspecting the tool's request & response, I see the following:

Request

{
  `pages`: [
    {
      `content`: `**Subject Line**: 🎟️ FREE: Learn ...`,
      `properties`: {
        `Name`: `[webinar-20250903-promo] Email - Initial Invite`,
        `Status`: `Review`,
        `Media Type`: `Written`,
        `Description`: `Email - Authority-focused invite with MVP credentials`,
        `Publish Date`: `2025-08-13`
      }
  ]
}

Response

{
  "name":"APIResponseError",
  "code":"validation_error",
  "status":400,
  "headers":{},
  "body":"{\"object\":\"error\",\"status\":400,\"code\":\"validation_error\",
                  \"message\":\"Property URL not found\",
                  \"request_id\":\"570bb569-54fe-46c6-87b4-140ac7b89ec8\
                "}"
}

As you can see, the payload generated by Claude with that create_pages tool doesn't have a URL property defined. While the database has a URL property, I can create pages with the underlying API and not set that property successfully...

[mxro]

I encounter exactly the same error message. To complicate things, I have a property named 'URL' in my database, but I suspect the error had nothing to do with my property but there is something else going on 🤕

[chewmen]

Same thing, but this time with GPT 5. It has started creating pages privately and then moving them to the correct database.

[chewmen]

I found the problem. If you have a property named "URL" it will fail. Once you rename the property, it will work fine.

[mxro]

@chewmen I can confirm the same for me.

Changing the property to name to something like 'Weblink' fixes the issue.

Definitely looks like some kind of a bug in the MCP server.