diff --git a/codex-rs/Cargo.lock b/codex-rs/Cargo.lock
index ba42adc6c2..2b0bda2a7e 100644
--- a/codex-rs/Cargo.lock
+++ b/codex-rs/Cargo.lock
@@ -3623,6 +3623,7 @@ dependencies = [
  "codex-utils-path-uri",
  "codex-utils-plugins",
  "futures",
+ "insta",
  "lru",
  "pretty_assertions",
  "regex-lite",
diff --git a/codex-rs/cli/src/mcp_cmd.rs b/codex-rs/cli/src/mcp_cmd.rs
index acc695eaf5..38a7f323a8 100644
--- a/codex-rs/cli/src/mcp_cmd.rs
+++ b/codex-rs/cli/src/mcp_cmd.rs
@@ -474,6 +474,7 @@ async fn run_add(config_overrides: &CliConfigOverrides, add_args: AddArgs) -> Re
     let mut servers = load_global_mcp_servers(&codex_home)
         .await
         .with_context(|| format!("failed to load MCP servers from {}", codex_home.display()))?;
+    let credential_name = new_entry.oauth_credential_name(&name);
     servers.insert(name.clone(), new_entry);
 
     ConfigEditsBuilder::new(&codex_home)
@@ -495,7 +496,7 @@ async fn run_add(config_overrides: &CliConfigOverrides, add_args: AddArgs) -> Re
                 oauth_config.discovered_scopes.clone(),
             );
             perform_oauth_login_retry_without_scopes(
-                &name,
+                credential_name.as_ref(),
                 &oauth_config.url,
                 config.mcp_oauth_credentials_store_mode,
                 config.auth_keyring_backend_kind(),
@@ -1123,12 +1124,12 @@ fn validate_server_name(name: &str) -> Result<()> {
     let is_valid = !name.is_empty()
         && name
             .chars()
-            .all(|c| c.is_ascii_alphanumeric() || c == '-' || c == '_');
+            .all(|c| c.is_ascii_alphanumeric() || matches!(c, '-' | '_' | ':' | '@' | '/' | '.'));
 
     if is_valid {
         Ok(())
     } else {
-        bail!("invalid server name '{name}' (use letters, numbers, '-', '_')");
+        bail!("invalid server name '{name}' (use letters, numbers, '-', '_', ':', '@', '/', '.')");
     }
 }
 
diff --git a/codex-rs/cli/tests/mcp_add_remove.rs b/codex-rs/cli/tests/mcp_add_remove.rs
index c5c65b9d9f..ca68faa061 100644
--- a/codex-rs/cli/tests/mcp_add_remove.rs
+++ b/codex-rs/cli/tests/mcp_add_remove.rs
@@ -73,6 +73,53 @@ async fn add_and_remove_server_updates_global_config() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test]
+async fn npm_server_names_round_trip_through_cli() -> Result<()> {
+    let codex_home = TempDir::new()?;
+    let name = "npm:@modelcontextprotocol/server-sequential.thinking";
+
+    codex_command(codex_home.path())?
+        .args(["mcp", "add", name, "--", "echo", "hello"])
+        .assert()
+        .success();
+
+    let config = std::fs::read_to_string(codex_home.path().join("config.toml"))?;
+    assert!(config.contains(&format!("[mcp_servers.\"{name}\"]")));
+    let servers = load_global_mcp_servers(codex_home.path()).await?;
+    assert_eq!(
+        servers.keys().map(String::as_str).collect::<Vec<_>>(),
+        vec![name]
+    );
+
+    let output = codex_command(codex_home.path())?
+        .args(["mcp", "get", name, "--json"])
+        .assert()
+        .success()
+        .get_output()
+        .stdout
+        .clone();
+    let server: serde_json::Value = serde_json::from_slice(&output)?;
+    assert_eq!(server["name"], name);
+
+    let output = codex_command(codex_home.path())?
+        .args(["mcp", "list", "--json"])
+        .assert()
+        .success()
+        .get_output()
+        .stdout
+        .clone();
+    let listed: Vec<serde_json::Value> = serde_json::from_slice(&output)?;
+    assert_eq!(listed.len(), 1);
+    assert_eq!(listed[0]["name"], name);
+
+    codex_command(codex_home.path())?
+        .args(["mcp", "remove", name])
+        .assert()
+        .success();
+    assert!(load_global_mcp_servers(codex_home.path()).await?.is_empty());
+    Ok(())
+}
+
 #[tokio::test]
 async fn add_and_login_discover_oauth_through_configured_http_proxy() -> Result<()> {
     let codex_home = TempDir::new()?;
diff --git a/codex-rs/codex-mcp/BUILD.bazel b/codex-rs/codex-mcp/BUILD.bazel
index fbae63201a..9b1b77ac8e 100644
--- a/codex-rs/codex-mcp/BUILD.bazel
+++ b/codex-rs/codex-mcp/BUILD.bazel
@@ -3,4 +3,5 @@ load("//:defs.bzl", "codex_rust_crate")
 codex_rust_crate(
     name = "codex-mcp",
     crate_name = "codex_mcp",
+    test_data_extra = glob(["src/**/snapshots/**"]),
 )
diff --git a/codex-rs/codex-mcp/Cargo.toml b/codex-rs/codex-mcp/Cargo.toml
index 3c6e7f0499..d989cf8b9c 100644
--- a/codex-rs/codex-mcp/Cargo.toml
+++ b/codex-rs/codex-mcp/Cargo.toml
@@ -46,6 +46,7 @@ url = { workspace = true }
 assert_matches = { workspace = true }
 codex-exec-server-test-support = { workspace = true }
 codex-plugin = { workspace = true }
+insta = { workspace = true }
 pretty_assertions = { workspace = true }
 rmcp = { workspace = true, default-features = false, features = ["base64", "macros", "schemars", "server"] }
 tempfile = { workspace = true }
diff --git a/codex-rs/codex-mcp/src/connection_manager/startup.rs b/codex-rs/codex-mcp/src/connection_manager/startup.rs
index 3052e2e965..5d4c1fdd53 100644
--- a/codex-rs/codex-mcp/src/connection_manager/startup.rs
+++ b/codex-rs/codex-mcp/src/connection_manager/startup.rs
@@ -78,6 +78,15 @@ pub(super) fn mcp_init_error_display(
     error: &StartupOutcomeError,
     reason: Option<McpStartupFailureReason>,
 ) -> String {
+    let server_key = if !server_name.is_empty()
+        && server_name
+            .chars()
+            .all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '-')
+    {
+        server_name.to_string()
+    } else {
+        serde_json::Value::String(server_name.to_string()).to_string()
+    };
     if let Some(McpServerTransportConfig::StreamableHttp {
         url,
         bearer_token_env_var,
@@ -89,7 +98,7 @@ pub(super) fn mcp_init_error_display(
         && http_headers.as_ref().map(HashMap::is_empty).unwrap_or(true)
     {
         format!(
-            "GitHub MCP does not support OAuth. Log in by adding a personal access token (https://github.com/settings/personal-access-tokens) to your environment and config.toml:\n[mcp_servers.{server_name}]\nbearer_token_env_var = CODEX_GITHUB_PERSONAL_ACCESS_TOKEN"
+            "GitHub MCP does not support OAuth. Log in by adding a personal access token (https://github.com/settings/personal-access-tokens) to your environment and config.toml:\n[mcp_servers.{server_key}]\nbearer_token_env_var = CODEX_GITHUB_PERSONAL_ACCESS_TOKEN"
         )
     } else if error.is_authentication_required() {
         let recovery_hint = if config.is_some_and(|config| !config.is_local_environment()) {
@@ -116,7 +125,7 @@ pub(super) fn mcp_init_error_display(
             .unwrap_or(DEFAULT_STARTUP_TIMEOUT)
             .as_secs();
         format!(
-            "MCP client for `{server_name}` timed out after {startup_timeout_secs} seconds. Add or adjust `startup_timeout_sec` in your config.toml:\n[mcp_servers.{server_name}]\nstartup_timeout_sec = XX"
+            "MCP client for `{server_name}` timed out after {startup_timeout_secs} seconds. Add or adjust `startup_timeout_sec` in your config.toml:\n[mcp_servers.{server_key}]\nstartup_timeout_sec = XX"
         )
     } else {
         format!("MCP client for `{server_name}` failed to start: {error:#}")
diff --git a/codex-rs/codex-mcp/src/connection_manager_tests.rs b/codex-rs/codex-mcp/src/connection_manager_tests.rs
index 8388d49c73..47aa905f6b 100644
--- a/codex-rs/codex-mcp/src/connection_manager_tests.rs
+++ b/codex-rs/codex-mcp/src/connection_manager_tests.rs
@@ -1806,25 +1806,35 @@ fn test_normalize_tools_disambiguates_sanitized_namespace_collisions() {
     let tools = vec![
         create_test_tool("basic-server", "lookup"),
         create_test_tool("basic_server", "query"),
+        create_test_tool("npm:@scope/package.name", "lookup"),
+        create_test_tool("npm__scope_package_name", "lookup"),
     ];
 
     let model_tools =
         normalize_tools_for_model_with_prefix(tools, /*prefix_mcp_tool_names*/ true, &[]);
 
-    assert_eq!(model_tools.len(), 2);
+    assert_eq!(model_tools.len(), 4);
     let mut namespaces = model_tools
         .iter()
         .map(|tool| tool.callable_namespace.as_str())
         .collect::<Vec<_>>();
     namespaces.sort();
     namespaces.dedup();
-    assert_eq!(namespaces.len(), 2);
+    assert_eq!(namespaces.len(), 4);
 
     let raw_servers = model_tools
         .iter()
         .map(|tool| tool.server_name.as_str())
         .collect::<HashSet<_>>();
-    assert_eq!(raw_servers, HashSet::from(["basic-server", "basic_server"]));
+    assert_eq!(
+        raw_servers,
+        HashSet::from([
+            "basic-server",
+            "basic_server",
+            "npm:@scope/package.name",
+            "npm__scope_package_name",
+        ])
+    );
     let model_names = model_tool_names(&model_tools);
     assert!(
         model_names.iter().all(is_code_mode_compatible_tool_name),
@@ -4573,6 +4583,27 @@ fn mcp_init_error_display_reports_generic_errors() {
     assert_eq!(expected, display);
 }
 
+#[test]
+fn mcp_init_error_display_quotes_server_names() {
+    let github_config: McpServerConfig = serde_json::from_value(serde_json::json!({
+        "url": "https://api.githubcopilot.com/mcp/",
+    }))
+    .expect("GitHub MCP configuration should deserialize");
+    let error: StartupOutcomeError = anyhow::anyhow!("request timed out").into();
+    let mut displays = Vec::new();
+    for server_name in ["npm:@scope/package.name", "server.name"] {
+        for config in [None, Some(&github_config)] {
+            displays.push(mcp_init_error_display(
+                server_name,
+                config,
+                &error,
+                /*reason*/ None,
+            ));
+        }
+    }
+    insta::assert_snapshot!(displays.join("\n\n"));
+}
+
 #[test]
 fn mcp_init_error_display_includes_startup_timeout_hint() {
     let server_name = "slow";
diff --git a/codex-rs/codex-mcp/src/rmcp_client.rs b/codex-rs/codex-mcp/src/rmcp_client.rs
index 563d6bedf1..1bf0cfc5b7 100644
--- a/codex-rs/codex-mcp/src/rmcp_client.rs
+++ b/codex-rs/codex-mcp/src/rmcp_client.rs
@@ -860,7 +860,7 @@ fn resolve_bearer_token(
 }
 
 fn validate_mcp_server_name(server_name: &str) -> Result<()> {
-    let re = regex_lite::Regex::new(r"^[a-zA-Z0-9_-]+$")?;
+    let re = regex_lite::Regex::new(r"^[a-zA-Z0-9_:@/.-]+$")?;
     if !re.is_match(server_name) {
         return Err(anyhow!(
             "Invalid MCP server name '{server_name}': must match pattern {pattern}",
diff --git a/codex-rs/codex-mcp/src/snapshots/codex_mcp__connection_manager__tests__mcp_init_error_display_quotes_server_names.snap b/codex-rs/codex-mcp/src/snapshots/codex_mcp__connection_manager__tests__mcp_init_error_display_quotes_server_names.snap
new file mode 100644
index 0000000000..555a69efc4
--- /dev/null
+++ b/codex-rs/codex-mcp/src/snapshots/codex_mcp__connection_manager__tests__mcp_init_error_display_quotes_server_names.snap
@@ -0,0 +1,19 @@
+---
+source: codex-mcp/src/connection_manager_tests.rs
+expression: "displays.join(\"\\n\\n\")"
+---
+MCP client for `npm:@scope/package.name` timed out after 30 seconds. Add or adjust `startup_timeout_sec` in your config.toml:
+[mcp_servers."npm:@scope/package.name"]
+startup_timeout_sec = XX
+
+GitHub MCP does not support OAuth. Log in by adding a personal access token (https://github.com/settings/personal-access-tokens) to your environment and config.toml:
+[mcp_servers."npm:@scope/package.name"]
+bearer_token_env_var = CODEX_GITHUB_PERSONAL_ACCESS_TOKEN
+
+MCP client for `server.name` timed out after 30 seconds. Add or adjust `startup_timeout_sec` in your config.toml:
+[mcp_servers."server.name"]
+startup_timeout_sec = XX
+
+GitHub MCP does not support OAuth. Log in by adding a personal access token (https://github.com/settings/personal-access-tokens) to your environment and config.toml:
+[mcp_servers."server.name"]
+bearer_token_env_var = CODEX_GITHUB_PERSONAL_ACCESS_TOKEN
diff --git a/codex-rs/core/tests/suite/rmcp_client.rs b/codex-rs/core/tests/suite/rmcp_client.rs
index 6f1b29b0ff..76a92f8ec6 100644
--- a/codex-rs/core/tests/suite/rmcp_client.rs
+++ b/codex-rs/core/tests/suite/rmcp_client.rs
@@ -864,9 +864,11 @@ async fn environment_mcp_policy_filters_runtime_config_and_model_tools(
     Ok(())
 }
 
+#[test_case("rmcp", "mcp__rmcp"; "simple name")]
+#[test_case("npm:@scope/package.name", "mcp__npm__scope_package_name"; "npm name")]
 #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
 #[serial(mcp_test_value)]
-async fn stdio_server_round_trip() -> anyhow::Result<()> {
+async fn stdio_server_round_trip(server_name: &'static str, namespace: &str) -> anyhow::Result<()> {
     // TODO(anp): Remove after packaging a Windows stdio test server for Wine exec.
     skip_if_wine_exec!(
         Ok(()),
@@ -878,8 +880,7 @@ async fn stdio_server_round_trip() -> anyhow::Result<()> {
 
     let call_id = "call-123";
     let search_call_id = "search-rmcp-echo";
-    let server_name = "rmcp";
-    let namespace = format!("mcp__{server_name}");
+    let namespace = namespace.to_string();
 
     let search_mock = mount_sse_once(
         &server,
@@ -1013,7 +1014,7 @@ async fn stdio_server_round_trip() -> anyhow::Result<()> {
         search_description.len() < 513 * 1024,
         "the complete tool search description must remain bounded"
     );
-    assert!(search_description.contains(&format!("- rmcp: {expected_description}")));
+    assert!(search_description.contains(&format!("- {server_name}: {expected_description}")));
     assert!(search_description.contains("🦀keep the complete MCP metadata"));
 
     let search_output = call_mock
diff --git a/codex-rs/rmcp-client/src/oauth.rs b/codex-rs/rmcp-client/src/oauth.rs
index 6b7eaae501..2880d8cba1 100644
--- a/codex-rs/rmcp-client/src/oauth.rs
+++ b/codex-rs/rmcp-client/src/oauth.rs
@@ -831,6 +831,9 @@ fn load_oauth_tokens_from_file_with_lock_held(
             false
         } else {
             entry.server_url == url
+                // Escaped names may also match another server's stored, escaped name.
+                // Only accept a legacy unescaped entry under this identity's own key.
+                && (!server_name.starts_with("local:") || stored_key == &key)
                 && (entry.server_name == local_server_name
                     || (stored_key == &key && entry.server_name == server_name))
         };
diff --git a/codex-rs/rmcp-client/src/oauth/tests/store_lock_tests.rs b/codex-rs/rmcp-client/src/oauth/tests/store_lock_tests.rs
index 37d82397d4..b8428f5e5e 100644
--- a/codex-rs/rmcp-client/src/oauth/tests/store_lock_tests.rs
+++ b/codex-rs/rmcp-client/src/oauth/tests/store_lock_tests.rs
@@ -110,6 +110,38 @@ fn sample_tokens() -> StoredOAuthTokens {
     }
 }
 
+#[test]
+fn file_credentials_keep_repeated_local_prefixes_isolated() -> Result<()> {
+    let _env = TempCodexHome::new();
+    let config: codex_config::McpServerConfig = serde_json::from_value(serde_json::json!({
+        "url": "https://example.test",
+    }))?;
+    let mut first = sample_tokens();
+    first.server_name = config.oauth_credential_name("local:foo").into_owned();
+    first.expires_at = None;
+    first.token_response.0.set_expires_in(None);
+    save_oauth_tokens_to_file(&first)?;
+
+    let second_name = config.oauth_credential_name("local:local:foo");
+    assert_eq!(load_oauth_tokens_from_file(&second_name, &first.url)?, None);
+
+    let mut second = first.clone();
+    second.server_name = second_name.into_owned();
+    second
+        .token_response
+        .0
+        .set_access_token(AccessToken::new("second-token".to_string()));
+    save_oauth_tokens_to_file(&second)?;
+
+    for expected in [first, second] {
+        assert_eq!(
+            load_oauth_tokens_from_file(&expected.server_name, &expected.url)?,
+            Some(expected)
+        );
+    }
+    Ok(())
+}
+
 #[test]
 fn legacy_rmcp_oauth_keyring_credentials_remain_readable() -> Result<()> {
     let _env = TempCodexHome::new();