MCP Configuration and debugging

What is the type of issue?

Enhancement

What is the issue?

Seems the config.toml isn't taking effect for MCPs, installed with brew install codex
`
network_access = true
disable_response_storage = true
model_reasoning_effort = "high"
[sandbox]
mode = "workspace-write"
[mcp_servers.context7]
command = "npx"
args = ["-y", "@upstash/context7-mcp"]
[mcp_servers.mcp-custom]
command = "node"
args = [
"/absolute_path/dist/mcp-custom.js",
"--transport",
"stdio",
]

`

Configuring custom MCPs is troublesome since the Codex CLI client intentionally silences all error output from the server. Makes it difficult to debug why f.ex. the custom MCP server works in Claude Code CLI with HTTP transport and Gemini CLI In Stdio transport but neither the official nor the custom MCP server works in Codex CLI.
Also support for HTTP servers would be welcome so one wouldn't need to host multiple server versions.
Overall a proper --debug flag utility would be a welcome addition to the CLI

Where did you find it?

mcp_client.rs line 95

Codex CLI Version: 0.1.2505172129
Node 24.2.0
npx 11.3.0