After configuring the MCP with Codex, you won't see any tools. First, confirm whether the server is loaded by the current client, then check startup, authentication, and tool filtering. Don't delete and reinstall configurations right away; Most problems can be located using /mcp in codex mcp list or TUI and a clear restart.
Step 1: Confirm that the modification is the same configuration
Codex apps, CLIs, and IDE extensions share Codex configurations, with the default location being ~/.codex/config.toml; Trusted projects can also use .codex/config.toml. If a different CODEX_HOME is set or the configuration file is switched, the current client may read another file. First, run:
codex mcp listIf there is no target name in the list, it means the configuration has not been read by the current environment.
Step 2: Let the client reload
After saving the MCP in the Codex App, click Restart; For IDE extensions, select Restart extension. After starting a new session in the CLI, enter /mcp in the TUI to confirm the server status and the exposed tools. If you only modify config.toml but continue using the old session, the tool list may not refresh.
Step 3: Distinguish between startup failure and authentication failure
STDIO servers rely on local commands, parameters, working directories, and environment variables. Copy the startup command from the configuration to the same terminal and run it directly; If the prompt does not exist or dependencies are missing, first repair the PATH and runtime environment. When the HTTP server needs OAuth, it executes:
codex mcp login <服务器名称>After authorization, restart the client. When the server starts slowly, it can improve startup_timeout_sec; The default startup wait time is only 10 seconds.
Step 4: Check if the tool is filtered
Configuration item enabled = false will disable the entire server, enabled_tools only allow the listed tools, disabled_tools will continue to exclude tools after the allowed list. When the server is connected but the number of tools is zero, prioritize checking these three items rather than doubting the model.
If the tool is still unavailable, keep the status shown by /mcp, startup command errors, and server logs. These three can clearly distinguish between "configuration not loaded," "process not started," "authorization not completed," and "tool filtered." Subsequent repairs only handle the corresponding layer.
