Error: MCP client for `<mcp name>` failed to start: MCP startup failed: missing field `type`

What version of Codex is running?

codex-cli 0.64.0-alpha.9

What subscription do you have?

unrelated

Which model were you using?

unrelated

What platform is your computer?

Linux 6.17.9-arch1-1 x86_64 unknown

What issue are you seeing?

In the start up of codex-cli, I have errors like:

⚠ error: MCP client for `<mcp name>` failed to start: MCP startup failed: missing field `type`

Cause

Because some of the the corresponding Rust SDK types do not have a field type, convert_to_mcp() in codex-rs/rmcp-client/src/utils.rs may return an error.

What steps can reproduce the bug?

In my machine, with the following config:

[mcp_servers.<mcp name>]
command = "mcp-server-filesystem"
args = ["<directory>"]

just running $ codex produce the error

error: MCP client for `<mcp name>` failed to start: MCP startup failed: missing field `type`

What is the expected behavior?

_No response_

Additional information

_No response_