diff --git a/codex-rs/rmcp-client/src/perform_oauth_login.rs b/codex-rs/rmcp-client/src/perform_oauth_login.rs
index eb6c7906a8..f878127dee 100644
--- a/codex-rs/rmcp-client/src/perform_oauth_login.rs
+++ b/codex-rs/rmcp-client/src/perform_oauth_login.rs
@@ -7,16 +7,12 @@ use anyhow::Context;
 use anyhow::Result;
 use anyhow::anyhow;
 use anyhow::bail;
-use base64::Engine;
-use base64::engine::general_purpose::URL_SAFE_NO_PAD;
 use reqwest::ClientBuilder;
 use reqwest::Url;
 use rmcp::transport::AuthorizationManager;
 use rmcp::transport::AuthorizationSession;
 use rmcp::transport::auth::OAuthClientConfig;
 use rmcp::transport::auth::OAuthState;
-use sha2::Digest;
-use sha2::Sha256;
 use tiny_http::Response;
 use tiny_http::Server;
 use tokio::sync::oneshot;
@@ -393,31 +389,6 @@ fn resolve_redirect_uri(server: &Server, callback_url: Option<&str>) -> Result<S
     Ok(callback_url.to_string())
 }
 
-fn callback_id_from_server_url(server_url: &str) -> Result<String> {
-    let mut parsed =
-        Url::parse(server_url).with_context(|| format!("invalid MCP server URL `{server_url}`"))?;
-    parsed
-        .host_str()
-        .ok_or_else(|| anyhow!("MCP server URL `{server_url}` must include a host"))?;
-    parsed.set_fragment(None);
-
-    let digest = Sha256::digest(parsed.as_str().as_bytes());
-    Ok(URL_SAFE_NO_PAD.encode(&digest[..9]))
-}
-
-fn append_callback_id_to_redirect_uri(redirect_uri: &str, callback_id: &str) -> Result<String> {
-    let mut parsed = Url::parse(redirect_uri)
-        .with_context(|| format!("invalid redirect URI `{redirect_uri}`"))?;
-    let path = parsed.path();
-    let new_path = if path.ends_with('/') {
-        format!("{path}{callback_id}")
-    } else {
-        format!("{path}/{callback_id}")
-    };
-    parsed.set_path(&new_path);
-    Ok(parsed.to_string())
-}
-
 fn callback_path_from_redirect_uri(redirect_uri: &str) -> Result<String> {
     let parsed = Url::parse(redirect_uri)
         .with_context(|| format!("invalid redirect URI `{redirect_uri}`"))?;
@@ -469,8 +440,6 @@ impl OauthLoginFlow {
         };
 
         let redirect_uri = resolve_redirect_uri(&server, callback_url)?;
-        let callback_id = callback_id_from_server_url(server_url)?;
-        let redirect_uri = append_callback_id_to_redirect_uri(&redirect_uri, &callback_id)?;
         let callback_path = callback_path_from_redirect_uri(&redirect_uri)?;
 
         let (tx, rx) = oneshot::channel();
@@ -665,9 +634,7 @@ mod tests {
 
     use super::CallbackOutcome;
     use super::OAuthProviderError;
-    use super::append_callback_id_to_redirect_uri;
     use super::append_query_param;
-    use super::callback_id_from_server_url;
     use super::callback_path_from_redirect_uri;
     use super::parse_oauth_callback;
     use super::start_authorization;
@@ -789,55 +756,6 @@ mod tests {
         assert_eq!(path, "/oauth/callback");
     }
 
-    #[test]
-    fn callback_id_is_bound_to_server_url() {
-        let callback_id = callback_id_from_server_url("https://mcp.example.com/mcp?tenant=one")
-            .expect("server URL should parse");
-        let same_without_fragment =
-            callback_id_from_server_url("https://mcp.example.com/mcp?tenant=one#unused")
-                .expect("server URL should parse");
-        let different_path = callback_id_from_server_url("https://mcp.example.com/sse?tenant=one")
-            .expect("server URL should parse");
-        let different_query = callback_id_from_server_url("https://mcp.example.com/mcp?tenant=two")
-            .expect("server URL should parse");
-        let different_origin = callback_id_from_server_url("https://mcp.example.com:8443/mcp")
-            .expect("server URL should parse");
-
-        assert_eq!(callback_id, same_without_fragment);
-        assert_ne!(callback_id, different_path);
-        assert_ne!(callback_id, different_query);
-        assert_ne!(callback_id, different_origin);
-        assert_eq!(callback_id.len(), 12);
-        assert!(
-            callback_id
-                .chars()
-                .all(|ch| ch.is_ascii_alphanumeric() || ch == '-' || ch == '_')
-        );
-    }
-
-    #[test]
-    fn callback_id_is_appended_to_redirect_uri_path() {
-        let redirect_uri =
-            append_callback_id_to_redirect_uri("http://127.0.0.1:1234/callback", "abc123")
-                .expect("redirect URI should parse");
-
-        assert_eq!(redirect_uri, "http://127.0.0.1:1234/callback/abc123");
-    }
-
-    #[test]
-    fn callback_id_is_appended_before_redirect_uri_query() {
-        let redirect_uri = append_callback_id_to_redirect_uri(
-            "https://callbacks.example.com/oauth/callback?provider=github",
-            "abc123",
-        )
-        .expect("redirect URI should parse");
-
-        assert_eq!(
-            redirect_uri,
-            "https://callbacks.example.com/oauth/callback/abc123?provider=github"
-        );
-    }
-
     #[test]
     fn append_query_param_adds_resource_to_absolute_url() {
         let url = append_query_param(