diff --git a/src/credentials/keyring.rs b/src/credentials/keyring.rs
index 3c50d05..dc2a722 100644
--- a/src/credentials/keyring.rs
+++ b/src/credentials/keyring.rs
@@ -13,10 +13,10 @@ use std::process::Command;
 
 const GO_KEYRING_BASE64: &str = "go-keyring-base64:";
 
-/// Fetch a secret, decoding go-keyring's base64 wrapper when present.
+/// Fetch a secret, decoding UTF-16LE and go-keyring's base64 wrapper when present.
 pub fn read(service: &str, account: &str) -> Option<Vec<u8>> {
     let raw = read_raw(service, account)?;
-    let text = String::from_utf8_lossy(&raw);
+    let text = decode_secret_bytes(&raw);
     let trimmed = text.trim();
     if trimmed.is_empty() {
         return None;
@@ -27,14 +27,44 @@ pub fn read(service: &str, account: &str) -> Option<Vec<u8>> {
     }
 }
 
+fn decode_secret_bytes(raw: &[u8]) -> String {
+    // Windows keyring crate (windows-native-keyring-store) stores password strings as UTF-16LE.
+    if raw.len() >= 2 && raw.len().is_multiple_of(2) && raw[1] == 0 && raw[0] != 0 {
+        let (chunks, _) = raw.as_chunks::<2>();
+        let units: Vec<u16> = chunks
+            .iter()
+            .map(|chunk| u16::from_le_bytes(*chunk))
+            .collect();
+        if let Ok(text) = String::from_utf16(&units) {
+            return text;
+        }
+    }
+    String::from_utf8_lossy(raw).to_string()
+}
+
 #[cfg(target_os = "windows")]
 fn read_raw(service: &str, account: &str) -> Option<Vec<u8>> {
+    for target_name in [
+        format!("{service}:{account}"),
+        format!("{account}.{service}"),
+        format!("{service}/{account}"),
+        format!("{service}.{account}"),
+    ] {
+        if let Some(secret) = read_target(&target_name) {
+            return Some(secret);
+        }
+    }
+    None
+}
+
+#[cfg(target_os = "windows")]
+fn read_target(target_name: &str) -> Option<Vec<u8>> {
     use std::os::windows::ffi::OsStrExt;
     use windows_sys::Win32::Security::Credentials::{
         CRED_TYPE_GENERIC, CREDENTIALW, CredFree, CredReadW,
     };
 
-    let target: Vec<u16> = std::ffi::OsStr::new(&format!("{service}:{account}"))
+    let target: Vec<u16> = std::ffi::OsStr::new(target_name)
         .encode_wide()
         .chain(std::iter::once(0))
         .collect();
diff --git a/src/credentials/mod.rs b/src/credentials/mod.rs
index 3b08191..6caddc5 100644
--- a/src/credentials/mod.rs
+++ b/src/credentials/mod.rs
@@ -192,19 +192,66 @@ pub fn load_codex() -> Option<Token> {
     })
 }
 
-/// The OAuth session Claude Code keeps in `~/.claude/.credentials.json`.
+/// The OAuth session Claude Code keeps in `~/.claude/.credentials.json`,
+/// falling back to the OS keyring entry from cairn-code if absent.
 pub fn load_claude() -> Option<Token> {
-    let root = read_json(&home_dir().join(".claude").join(".credentials.json"))?;
-    let oauth = root.get("claudeAiOauth")?;
+    if let Some(root) = read_json(&home_dir().join(".claude").join(".credentials.json"))
+        && let Some(token) = parse_claude(&root)
+    {
+        return Some(token);
+    }
 
-    Some(Token {
-        access_token: string_at(oauth, "accessToken")?,
-        refresh_token: string_at(oauth, "refreshToken").unwrap_or_default(),
-        expires_at: expiry_at(oauth, &["expiresAt", "expires_at"]),
-        email: first_string(&[oauth, &root], &["email"]),
-        plan_type: first_string(&[oauth, &root], &["subscriptionType"]),
-        ..Default::default()
-    })
+    for (service, account) in [
+        ("cairn-code", "oauth:claude"),
+        ("cairn-code", "claude"),
+        ("claude", "credentials"),
+    ] {
+        if let Some(data) = keyring::read(service, account)
+            && let Ok(value) = serde_json::from_slice::<Value>(&data)
+            && let Some(token) = parse_claude(&value)
+        {
+            return Some(token);
+        }
+    }
+
+    None
+}
+
+pub(crate) fn parse_claude(root: &Value) -> Option<Token> {
+    if let Some(oauth) = root.get("claudeAiOauth") {
+        return Some(Token {
+            access_token: string_at(oauth, "accessToken")?,
+            refresh_token: string_at(oauth, "refreshToken").unwrap_or_default(),
+            expires_at: expiry_at(oauth, &["expiresAt", "expires_at"]),
+            email: first_string(&[oauth, root], &["email"]),
+            plan_type: first_string(&[oauth, root], &["subscriptionType"]),
+            ..Default::default()
+        });
+    }
+
+    // Direct OAuth token object (from keyring)
+    if let Some(access_token) =
+        string_at(root, "access_token").or_else(|| string_at(root, "accessToken"))
+    {
+        let refresh_token = string_at(root, "refresh_token")
+            .or_else(|| string_at(root, "refreshToken"))
+            .unwrap_or_default();
+        let mut email = string_at(root, "email").unwrap_or_default();
+        if email.is_empty() {
+            email = email_from_jwt(&access_token);
+        }
+        return Some(Token {
+            access_token,
+            refresh_token,
+            expires_at: expiry_at(root, &["expires_at", "expiresAt"]),
+            email,
+            plan_type: first_string(&[root], &["subscriptionType", "plan_type", "plan"]),
+            auth_method: "oauth".into(),
+            ..Default::default()
+        });
+    }
+
+    None
 }
 
 /// The Google OAuth credentials the Gemini CLI writes.
@@ -218,21 +265,88 @@ pub fn load_gemini() -> Option<Token> {
     })
 }
 
-/// The Grok CLI's `~/.grok/auth.json`, which is a map of account entries.
+/// The Grok / xAI token from the OS keyring (cairn-code device OAuth / API key)
+/// or the Grok CLI's `~/.grok/auth.json`.
 pub fn load_grok() -> Option<Token> {
+    for (service, account) in [
+        ("cairn-code", "oauth:xai"),
+        ("cairn-code", "xai"),
+        ("grok", "auth"),
+        ("grok", "oauth:grok"),
+    ] {
+        if let Some(data) = keyring::read(service, account) {
+            if let Ok(value) = serde_json::from_slice::<Value>(&data) {
+                if let Some(token) = parse_grok(&value) {
+                    return Some(token);
+                }
+            } else {
+                let key = String::from_utf8_lossy(&data).trim().to_string();
+                if !key.is_empty() && !key.starts_with('{') {
+                    return Some(Token {
+                        access_token: key,
+                        auth_method: "api_key".into(),
+                        ..Default::default()
+                    });
+                }
+            }
+        }
+    }
+
     let root = read_json(&home_dir().join(".grok").join("auth.json"))?;
-    let entries = root.as_object()?;
+    parse_grok(&root)
+}
 
-    entries.values().find_map(|entry| {
-        let access_token = string_at(entry, "key")?;
-        Some(Token {
+pub(crate) fn parse_grok(root: &Value) -> Option<Token> {
+    // 1. If root is a map of account entries (as in ~/.grok/auth.json):
+    if let Some(entries) = root.as_object()
+        && let Some(token) = entries.values().find_map(parse_grok_entry)
+    {
+        return Some(token);
+    }
+    // 2. Direct token object (as in cairn-code keyring or single entry)
+    parse_grok_entry(root)
+}
+
+fn parse_grok_entry(entry: &Value) -> Option<Token> {
+    // OAuth token format (cairn-code / device OAuth): "access_token"
+    if let Some(access_token) =
+        string_at(entry, "access_token").or_else(|| string_at(entry, "accessToken"))
+    {
+        let refresh_token = string_at(entry, "refresh_token")
+            .or_else(|| string_at(entry, "refreshToken"))
+            .unwrap_or_default();
+        let mut email = string_at(entry, "email").unwrap_or_default();
+        if email.is_empty() {
+            email = email_from_jwt(&access_token);
+        }
+        let id_token = string_at(entry, "id_token").unwrap_or_default();
+        if email.is_empty() && !id_token.is_empty() {
+            email = email_from_jwt(&id_token);
+        }
+        return Some(Token {
+            access_token,
+            refresh_token,
+            email,
+            expires_at: expiry_at(entry, &["expires_at", "expiresAt", "expiry"]),
+            auth_method: string_at(entry, "auth_mode")
+                .or_else(|| string_at(entry, "token_type"))
+                .unwrap_or_else(|| "oauth".into()),
+            ..Default::default()
+        });
+    }
+
+    // CLI format (~/.grok/auth.json): "key"
+    if let Some(access_token) = string_at(entry, "key") {
+        return Some(Token {
             access_token,
             email: string_at(entry, "email").unwrap_or_default(),
-            expires_at: expiry_at(entry, &["expires_at"]),
+            expires_at: expiry_at(entry, &["expires_at", "expiresAt"]),
             auth_method: string_at(entry, "auth_mode").unwrap_or_else(|| "oidc".into()),
             ..Default::default()
-        })
-    })
+        });
+    }
+
+    None
 }
 
 /// Antigravity's OAuth token, from the keyring first and the on-disk stores
@@ -541,6 +655,63 @@ mod tests {
         }
     }
 
+    #[test]
+    fn parse_grok_oauth_payload() {
+        let payload = json!({
+            "access_token": "xai-oauth-access-token",
+            "refresh_token": "xai-refresh-token",
+            "token_type": "Bearer",
+            "expires_at": 1786741307,
+            "scopes": ["openid", "profile", "email"]
+        });
+        let token = parse_grok(&payload).unwrap();
+        assert_eq!(token.access_token, "xai-oauth-access-token");
+        assert_eq!(token.refresh_token, "xai-refresh-token");
+        assert_eq!(token.expires_at, Some(1786741307));
+    }
+
+    #[test]
+    fn parse_grok_cli_auth_json_map() {
+        let payload = json!({
+            "account1": {
+                "key": "xai-api-key-test",
+                "email": "grokuser@example.com",
+                "expires_at": 1786741307,
+                "auth_mode": "oidc"
+            }
+        });
+        let token = parse_grok(&payload).unwrap();
+        assert_eq!(token.access_token, "xai-api-key-test");
+        assert_eq!(token.email, "grokuser@example.com");
+        assert_eq!(token.auth_method, "oidc");
+    }
+
+    #[test]
+    fn parse_claude_oauth_direct_and_nested() {
+        let nested = json!({
+            "claudeAiOauth": {
+                "accessToken": "claude-nested-token",
+                "refreshToken": "claude-refresh",
+                "expiresAt": "2026-08-14T21:01:47Z",
+                "email": "user@claude.ai",
+                "subscriptionType": "pro"
+            }
+        });
+        let tok1 = parse_claude(&nested).unwrap();
+        assert_eq!(tok1.access_token, "claude-nested-token");
+        assert_eq!(tok1.email, "user@claude.ai");
+
+        let direct = json!({
+            "access_token": "claude-direct-token",
+            "refresh_token": "claude-direct-refresh",
+            "expires_at": 1786741307,
+            "subscriptionType": "max"
+        });
+        let tok2 = parse_claude(&direct).unwrap();
+        assert_eq!(tok2.access_token, "claude-direct-token");
+        assert_eq!(tok2.plan_type, "max");
+    }
+
     #[test]
     fn a_token_without_an_expiry_is_treated_as_fresh() {
         let token = Token {
diff --git a/src/parsers/claude.rs b/src/parsers/claude.rs
index 97ac943..36fb89e 100644
--- a/src/parsers/claude.rs
+++ b/src/parsers/claude.rs
@@ -14,18 +14,18 @@ struct Payload {
 #[derive(Debug, Deserialize)]
 struct Bucket {
     #[serde(default)]
-    utilization: f64,
+    utilization: Option<f64>,
     #[serde(default)]
-    resets_at: String,
+    resets_at: Option<String>,
 }
 
 impl Bucket {
     fn into_window(self, label: &str, seconds: i64) -> UsageWindow {
-        let countdown = match self.resets_at.trim() {
-            "" => "Unknown".to_string(),
-            at => format_countdown(at),
+        let countdown = match self.resets_at.as_deref().map(str::trim) {
+            None | Some("") => "Unknown".to_string(),
+            Some(at) => format_countdown(at),
         };
-        UsageWindow::new(label, self.utilization)
+        UsageWindow::new(label, self.utilization.unwrap_or(0.0))
             .reset(countdown)
             .seconds(seconds)
     }
@@ -103,6 +103,17 @@ mod tests {
         assert_eq!(windows[0].reset_countdown, "Unknown");
     }
 
+    #[test]
+    fn null_fields_in_bucket_survive_deserialization() {
+        let windows = parse(r#"{"five_hour":{"utilization":0.0,"resets_at":null},"seven_day":{"utilization":99.0,"resets_at":"2026-08-18T10:59:59.644698+00:00"}}"#);
+        assert_eq!(windows.len(), 2);
+        assert_eq!(windows[0].label, "Session");
+        assert_eq!(windows[0].used_percent, 0.0);
+        assert_eq!(windows[0].reset_countdown, "Unknown");
+        assert_eq!(windows[1].label, "Weekly");
+        assert_eq!(windows[1].used_percent, 99.0);
+    }
+
     #[test]
     fn an_unusable_payload_yields_no_windows() {
         assert!(parse("{}").is_empty());