diff --git a/open-sse/services/usage.ts b/open-sse/services/usage.ts
index 2bf2edec5f..820f7cfb4a 100644
--- a/open-sse/services/usage.ts
+++ b/open-sse/services/usage.ts
@@ -554,9 +554,7 @@ async function getGlmUsage(apiKey: string, providerSpecificData?: Record<string,
   }
 
   const levelRaw = typeof data.level === "string" ? data.level : "";
-  const plan = levelRaw
-    ? levelRaw.charAt(0).toUpperCase() + levelRaw.slice(1).toLowerCase()
-    : "Unknown";
+  const plan = levelRaw ? levelRaw.charAt(0).toUpperCase() + levelRaw.slice(1).toLowerCase() : null;
 
   return { plan, quotas };
 }
@@ -1820,7 +1818,7 @@ async function getClaudeUsageLegacy(accessToken) {
         if (usageResponse.ok) {
           const usage = await usageResponse.json();
           return {
-            plan: settings.plan || "Unknown",
+            plan: settings.plan || null,
             organization: settings.organization_name,
             quotas: usage,
           };
@@ -1828,7 +1826,7 @@ async function getClaudeUsageLegacy(accessToken) {
       }
 
       return {
-        plan: settings.plan || "Unknown",
+        plan: settings.plan || null,
         organization: settings.organization_name,
         message: "Claude connected. Usage details require admin access.",
       };
diff --git a/src/lib/oauth/providers/claude.ts b/src/lib/oauth/providers/claude.ts
index 6f3f3eb560..3f6f6aa56c 100644
--- a/src/lib/oauth/providers/claude.ts
+++ b/src/lib/oauth/providers/claude.ts
@@ -1,5 +1,43 @@
 import { CLAUDE_CONFIG } from "../constants/oauth";
 
+function toRecord(value: unknown): Record<string, unknown> {
+  return value && typeof value === "object" && !Array.isArray(value)
+    ? (value as Record<string, unknown>)
+    : {};
+}
+
+function firstNonEmptyString(...values: unknown[]): string | undefined {
+  for (const value of values) {
+    if (typeof value !== "string") {
+      continue;
+    }
+
+    const trimmed = value.trim();
+    if (trimmed) {
+      return trimmed;
+    }
+  }
+
+  return undefined;
+}
+
+function extractPlanFromPayload(payload: unknown): string | undefined {
+  const data = toRecord(payload);
+  const billing = toRecord(data.billing);
+
+  return firstNonEmptyString(data.account_tier, data.plan, data.subscription_type, billing.plan);
+}
+
+function extractClaudePlan(tokens: unknown, extra: unknown): string | undefined {
+  const extraData = toRecord(extra);
+
+  return firstNonEmptyString(
+    extractPlanFromPayload(tokens),
+    extractPlanFromPayload(extraData.userInfo),
+    extractPlanFromPayload(extra)
+  );
+}
+
 export const claude = {
   config: CLAUDE_CONFIG,
   flowType: "authorization_code_pkce",
@@ -48,10 +86,15 @@ export const claude = {
 
     return await response.json();
   },
-  mapTokens: (tokens) => ({
-    accessToken: tokens.access_token,
-    refreshToken: tokens.refresh_token,
-    expiresIn: tokens.expires_in,
-    scope: tokens.scope,
-  }),
+  mapTokens: (tokens, extra) => {
+    const plan = extractClaudePlan(tokens, extra);
+
+    return {
+      accessToken: tokens.access_token,
+      refreshToken: tokens.refresh_token,
+      expiresIn: tokens.expires_in,
+      scope: tokens.scope,
+      providerSpecificData: plan ? { plan } : undefined,
+    };
+  },
 };
diff --git a/tests/unit/claude-oauth-provider.test.ts b/tests/unit/claude-oauth-provider.test.ts
index c451391a24..963a48b562 100644
--- a/tests/unit/claude-oauth-provider.test.ts
+++ b/tests/unit/claude-oauth-provider.test.ts
@@ -75,3 +75,33 @@ test("Claude OAuth provider always uses the configured redirectUri during token
   assert.equal(captured.body.state, "state-from-fragment");
   assert.equal(captured.body.code_verifier, "verifier-123");
 });
+
+test("Claude OAuth token mapper persists the first non-empty token plan field", () => {
+  const cases = [
+    [{ account_tier: " Pro ", plan: "Max" }, "Pro"],
+    [{ account_tier: "", plan: "Max" }, "Max"],
+    [{ plan: "", subscription_type: "Team" }, "Team"],
+    [{ subscription_type: "", billing: { plan: "Enterprise" } }, "Enterprise"],
+  ];
+
+  for (const [tokens, expected] of cases) {
+    const mapped = claude.mapTokens({ access_token: "token-1", ...tokens });
+
+    assert.equal(mapped.providerSpecificData.plan, expected);
+  }
+});
+
+test("Claude OAuth token mapper reads plan fields from userinfo extras after token fields", () => {
+  const mapped = claude.mapTokens(
+    { access_token: "token-1" },
+    { userInfo: { account_tier: "", subscription_type: "Max" } }
+  );
+
+  assert.equal(mapped.providerSpecificData.plan, "Max");
+});
+
+test("Claude OAuth token mapper leaves providerSpecificData.plan undefined without plan fields", () => {
+  const mapped = claude.mapTokens({ access_token: "token-1", scope: "user:profile" });
+
+  assert.equal(mapped.providerSpecificData, undefined);
+});
diff --git a/tests/unit/provider-limits-ui.test.ts b/tests/unit/provider-limits-ui.test.ts
index ae40f8b868..2c78c2969c 100644
--- a/tests/unit/provider-limits-ui.test.ts
+++ b/tests/unit/provider-limits-ui.test.ts
@@ -30,6 +30,17 @@ test("Codex workspacePlanType is used when live plan is missing or unknown", ()
   assert.equal(tier.variant, "success");
 });
 
+test("Claude providerSpecificData plan is used when live plan is missing", () => {
+  const resolvedPlan = providerLimitUtils.resolvePlanValue(null, {
+    plan: "Pro",
+  });
+
+  assert.equal(resolvedPlan, "Pro");
+  const tier = providerLimitUtils.normalizePlanTier(resolvedPlan);
+  assert.equal(tier.key, "pro");
+  assert.equal(tier.variant, "success");
+});
+
 test("remaining percentage helpers reflect remaining quota and stale resets refill to 100", () => {
   assert.equal(providerLimitUtils.calculatePercentage(0, 100), 100);
   assert.equal(providerLimitUtils.calculatePercentage(17, 100), 83);