Server fails when used through Claude Code (JSON schema is invalid)

[TechNickAI]

I really like being able to use this logfire MCP server with Cursor. And it works great there, but when I use it in Claude Code with the identical config, I get the following error from Claude code

  ⎿ API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"tools.29.custom.input_schema: JSON schema is 
    invalid. It must match JSON Schema draft 2020-12 (https://json-schema.org/draft/2020-12). Learn more about tool use at 
    https://docs.anthropic.com/en/docs/tool-use."}}

Here is the config that I am using:

{
  "mcpServers": {
    "logfire": {
      "command": "uvx",
      "args": ["logfire-mcp@latest"],
      "env": {
        "LOGFIRE_READ_TOKEN": "xxxxxx",
        "LOGFIRE_BASE_URL": "https://api-eu.pydantic.dev"
      }
    }
}

Other MCP servers work fine for me in claude code. When ever I use clade code, I have to comment out the logfire server.

[hramezani]

We are not going to update this repo and add more tools.
You can use our MCP server, and you can find configuration instructions in README.md

[semoal]

We're having the same issue using the MCP Server through the remote url
JSON Schema not supported: could not understand the instance {'title': 'Spec'}.

[hramezani]

I think you are using EU region MCP, and I assume you are using this configuration:

{
  "mcpServers": {
    "logfire": {
      "type": "http",
      "url": "https://logfire-eu.pydantic.dev/mcp"
    }
  }
}

right?

You have to authenticate first to be able to use it

Can you provide more information to help us debug?

[hramezani]

This repository is being archived. The STDIO MCP server is no longer being updated — we now have a remote MCP server, which allows us to iterate faster on tools and provide a better experience.

For setup instructions, see Logfire MCP Server documentation.