mcp.md Codex Docs, 2026-03-18 00:36 UTC → 2026-04-16 00:46 UTC

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80If your MCP OAuth flow must use a specific callback URL (for example, a remote devbox ingress URL or a custom callback path), set `mcp_oauth_callback_url`. Codex uses this value as the OAuth `redirect_uri` while still using `mcp_oauth_callback_port` for the callback listener port. Local callback URLs (for example `localhost`) bind on loopback; non-local callback URLs bind on `0.0.0.0` so the callback can reach the host.80If your MCP OAuth flow must use a specific callback URL (for example, a remote devbox ingress URL or a custom callback path), set `mcp_oauth_callback_url`. Codex uses this value as the OAuth `redirect_uri` while still using `mcp_oauth_callback_port` for the callback listener port. Local callback URLs (for example `localhost`) bind on loopback; non-local callback URLs bind on `0.0.0.0` so the callback can reach the host.

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82If the MCP server advertises `scopes_supported`, Codex prefers those

83server-advertised scopes during OAuth login. Otherwise, Codex falls back to the

84scopes configured in `config.toml`.

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82#### config.toml examples86#### config.toml examples

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84```toml88```toml