openai/codex · error · anyhow::Error

No MCP server named '{name}' found.

Error message

No MCP server named '{name}' found.

What it means

`codex mcp login <name>` resolves the server by exact key lookup in the configured mcp_servers map before starting the OAuth flow. A missing key bails immediately with the name you passed; nothing is written and no browser flow starts.

Source

Thrown at codex-rs/cli/src/mcp_cmd.rs:545

    ));
    Ok(McpManager::new(plugins_manager))
}

async fn run_login(config: &Config, login_args: LoginArgs) -> Result<()> {
    let mcp_manager = load_mcp_manager(config).await?;
    let mcp_servers = mcp_manager.configured_servers(config).await;

    let LoginArgs {
        name,
        scopes,
        oauth_client_registration,
    } = login_args;
    let client_registration = oauth_client_registration
        .map(McpOAuthClientRegistration::from)
        .unwrap_or_default();

    let Some(server) = mcp_servers.get(&name) else {
        bail!("No MCP server named '{name}' found.");
    };

    let (url, http_headers, env_http_headers) = match &server.transport {
        McpServerTransportConfig::StreamableHttp {
            url,
            http_headers,
            env_http_headers,
            ..
        } => (url.clone(), http_headers.clone(), env_http_headers.clone()),
        _ => bail!("OAuth login is only supported for streamable HTTP servers."),
    };

    // Standalone `mcp login` runs OAuth from the local CLI process; execution
    // environment routing belongs to app-server and session MCP flows.
    let http_client: Arc<dyn HttpClient> = Arc::new(
        RouteAwareHttpClient::new(config.http_client_factory()).with_tls_backend_fallback(),
    );
    let http_client = apply_http_headers_helper(http_client, server, config.cwd.to_path_buf())

View on GitHub (pinned to 339751715c)

Solutions

1. List configured servers and copy the exact key: `codex mcp list`.
2. Add it first if missing: `codex mcp add <name> --url https://...`, then `codex mcp login <name>`.
3. Match the name byte-for-byte — the lookup is case-sensitive.
4. Confirm you are running against the right CODEX_HOME/profile.

Example fix

# before
codex mcp login contex7               # typo: server is context7
# after
codex mcp list                        # copy the exact name
codex mcp login context7

# or add it first if missing:
codex mcp add context7 --url https://mcp.context7.com/mcp
codex mcp login context7

mcp_login() {
  local name="$1"
  codex mcp list 2>/dev/null | grep -Fw -- "$name" >/dev/null || {
    echo "no MCP server named '$name' configured; run: codex mcp add $name --url <url>" >&2
    return 2
  }
  codex mcp login "$name"
}

if ! codex mcp login "$name" 2>err.log; then
  if grep -q 'No MCP server named' err.log; then
    codex mcp list   # surface valid names so the caller can retry with the exact key
  fi
  exit 1
fi

When it happens

Trigger: `codex mcp login context7` when no server with that exact key is configured — typo, different casing, server configured in another profile/CODEX_HOME, or never added.

Common situations: Transcribing a name from docs with different casing or spacing; the server was added under a different key via `codex mcp add`; multiple config files or profiles so `codex mcp list` in another environment shows the server; stale tutorials referencing renamed servers.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

• command is required
• exactly one of --command or --url must be provided
• `--remote-auth-token-env` is only supported for interactive
• `--strict-config` is not supported for `codex {subcommand}`
• environment variable `{env_var_name}` is not set

AI-assisted analysis of openai/codex@339751715c (2026-08-25). Data as JSON: /api/errors/a734bbe14915878b. Report an issue: GitHub.