diff --git a/codex-rs/core/src/auth.rs b/codex-rs/core/src/auth.rs
index 85fb1721..b18cae5f 100644
--- a/codex-rs/core/src/auth.rs
+++ b/codex-rs/core/src/auth.rs
@@ -25,6 +25,7 @@ use crate::default_client::CodexHttpClient;
 use crate::token_data::PlanType;
 use crate::token_data::TokenData;
 use crate::token_data::parse_id_token;
+use crate::util::try_parse_error_message;
 
 #[derive(Debug, Clone)]
 pub struct CodexAuth {
@@ -42,6 +43,9 @@ impl PartialEq for CodexAuth {
     }
 }
 
+// TODO(pakrym): use token exp field to check for expiration instead
+const TOKEN_REFRESH_INTERVAL: i64 = 8;
+
 impl CodexAuth {
     pub async fn refresh_token(&self) -> Result<String, std::io::Error> {
         tracing::info!("Refreshing token");
@@ -94,7 +98,7 @@ impl CodexAuth {
                 last_refresh: Some(last_refresh),
                 ..
             }) => {
-                if last_refresh < Utc::now() - chrono::Duration::days(28) {
+                if last_refresh < Utc::now() - chrono::Duration::days(TOKEN_REFRESH_INTERVAL) {
                     let refresh_response = tokio::time::timeout(
                         Duration::from_secs(60),
                         try_refresh_token(tokens.refresh_token.clone(), &self.client),
@@ -446,8 +450,9 @@ async fn try_refresh_token(
         Ok(refresh_response)
     } else {
         Err(std::io::Error::other(format!(
-            "Failed to refresh token: {}",
-            response.status()
+            "Failed to refresh token: {}: {}",
+            response.status(),
+            try_parse_error_message(&response.text().await.unwrap_or_default()),
         )))
     }
 }
diff --git a/codex-rs/core/src/util.rs b/codex-rs/core/src/util.rs
index 8ef258d9..59e3154b 100644
--- a/codex-rs/core/src/util.rs
+++ b/codex-rs/core/src/util.rs
@@ -1,6 +1,7 @@
 use std::time::Duration;
 
 use rand::Rng;
+use tracing::debug;
 
 const INITIAL_DELAY_MS: u64 = 200;
 const BACKOFF_FACTOR: f64 = 2.0;
@@ -11,3 +12,47 @@ pub(crate) fn backoff(attempt: u64) -> Duration {
     let jitter = rand::rng().random_range(0.9..1.1);
     Duration::from_millis((base as f64 * jitter) as u64)
 }
+
+pub(crate) fn try_parse_error_message(text: &str) -> String {
+    debug!("Parsing server error response: {}", text);
+    let json = serde_json::from_str::<serde_json::Value>(text).unwrap_or_default();
+    if let Some(error) = json.get("error")
+        && let Some(message) = error.get("message")
+        && let Some(message_str) = message.as_str()
+    {
+        return message_str.to_string();
+    }
+    if text.is_empty() {
+        return "Unknown error".to_string();
+    }
+    text.to_string()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_try_parse_error_message() {
+        let text = r#"{
+  "error": {
+    "message": "Your refresh token has already been used to generate a new access token. Please try signing in again.",
+    "type": "invalid_request_error",
+    "param": null,
+    "code": "refresh_token_reused"
+  }
+}"#;
+        let message = try_parse_error_message(text);
+        assert_eq!(
+            message,
+            "Your refresh token has already been used to generate a new access token. Please try signing in again."
+        );
+    }
+
+    #[test]
+    fn test_try_parse_error_message_no_error() {
+        let text = r#"{"message": "test"}"#;
+        let message = try_parse_error_message(text);
+        assert_eq!(message, r#"{"message": "test"}"#);
+    }
+}