diff --git a/packages/server/src/services/quota-fetcher/providers/claude-keychain.test.ts b/packages/server/src/services/quota-fetcher/providers/claude-keychain.test.ts
new file mode 100644
index 000000000..0f6be01f3
--- /dev/null
+++ b/packages/server/src/services/quota-fetcher/providers/claude-keychain.test.ts
@@ -0,0 +1,87 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { claudeKeychainAccount, readClaudeKeychainCredentials } from "./claude.js";
+
+const SERVICE = "Claude Code-credentials";
+
+afterEach(() => {
+  vi.unstubAllEnvs();
+});
+
+describe("claudeKeychainAccount", () => {
+  it("uses a supported username verbatim", () => {
+    expect(claudeKeychainAccount("thomas.benoit")).toBe("thomas.benoit");
+  });
+
+  it("falls back to claude-code-user when the username carries a rejected character", () => {
+    expect(claudeKeychainAccount("first.last@example.com")).toBe("claude-code-user");
+  });
+
+  it("reads the username from $USER when no account is given", () => {
+    vi.stubEnv("USER", "ci-runner");
+    expect(claudeKeychainAccount()).toBe("ci-runner");
+
+    vi.stubEnv("USER", "first.last@example.com");
+    expect(claudeKeychainAccount()).toBe("claude-code-user");
+  });
+});
+
+describe("readClaudeKeychainCredentials", () => {
+  it("looks the item up by account and stops there when it exists", async () => {
+    const run = vi.fn(async () => JSON.stringify({ claudeAiOauth: { accessToken: "at_fresh" } }));
+
+    const credentials = await readClaudeKeychainCredentials(run, "claude-code-user");
+
+    expect(credentials).toEqual({ claudeAiOauth: { accessToken: "at_fresh" } });
+    expect(run).toHaveBeenCalledTimes(1);
+    expect(run).toHaveBeenCalledWith([
+      "find-generic-password",
+      "-a",
+      "claude-code-user",
+      "-w",
+      "-s",
+      SERVICE,
+    ]);
+  });
+
+  it("falls back to the account-less lookup when no item matches the account", async () => {
+    const run = vi.fn(async (args: string[]) =>
+      args.includes("-a") ? null : JSON.stringify({ claudeAiOauth: { accessToken: "at_legacy" } }),
+    );
+
+    const credentials = await readClaudeKeychainCredentials(run, "claude-code-user");
+
+    expect(credentials).toEqual({ claudeAiOauth: { accessToken: "at_legacy" } });
+    expect(run).toHaveBeenNthCalledWith(2, ["find-generic-password", "-w", "-s", SERVICE]);
+  });
+
+  it("falls through when the account item carries no access token", async () => {
+    const run = vi.fn(async (args: string[]) =>
+      args.includes("-a")
+        ? JSON.stringify({ claudeAiOauth: { subscriptionType: "team" } })
+        : JSON.stringify({ claudeAiOauth: { accessToken: "at_legacy" } }),
+    );
+
+    const credentials = await readClaudeKeychainCredentials(run, "claude-code-user");
+
+    expect(credentials).toEqual({ claudeAiOauth: { accessToken: "at_legacy" } });
+    expect(run).toHaveBeenCalledTimes(2);
+  });
+
+  it("is null when the Keychain holds no item at all", async () => {
+    const run = vi.fn(async () => null);
+
+    expect(await readClaudeKeychainCredentials(run, "claude-code-user")).toBeNull();
+  });
+
+  it("tries the next lookup when the item does not parse", async () => {
+    const run = vi.fn(async (args: string[]) =>
+      args.includes("-a")
+        ? "not-json"
+        : JSON.stringify({ claudeAiOauth: { accessToken: "at_legacy" } }),
+    );
+
+    expect(await readClaudeKeychainCredentials(run, "claude-code-user")).toEqual({
+      claudeAiOauth: { accessToken: "at_legacy" },
+    });
+  });
+});
diff --git a/packages/server/src/services/quota-fetcher/providers/claude.ts b/packages/server/src/services/quota-fetcher/providers/claude.ts
index 0ff4e9b8b..be922d085 100644
--- a/packages/server/src/services/quota-fetcher/providers/claude.ts
+++ b/packages/server/src/services/quota-fetcher/providers/claude.ts
@@ -1,6 +1,6 @@
 import { execFile } from "node:child_process";
 import { existsSync, promises as fs } from "node:fs";
-import { homedir } from "node:os";
+import { homedir, userInfo } from "node:os";
 import { join } from "node:path";
 import { promisify } from "node:util";
 import type { Logger } from "pino";
@@ -297,21 +297,54 @@ function scopedWindows(limits: ScopedLimit[]): ProviderUsageWindow[] {
   });
 }
 
-async function readClaudeKeychainCredentials(): Promise<unknown | null> {
+type ClaudeKeychainCommandRunner = (args: string[]) => Promise<string | null>;
+
+// Keep this in sync with Claude Code's Keychain account derivation.
+const CLAUDE_KEYCHAIN_ACCOUNT_PATTERN = /^[a-zA-Z0-9._-]+$/;
+const CLAUDE_KEYCHAIN_FALLBACK_ACCOUNT = "claude-code-user";
+
+export function claudeKeychainAccount(
+  user: string = process.env["USER"] || userInfo().username,
+): string {
+  return CLAUDE_KEYCHAIN_ACCOUNT_PATTERN.test(user) ? user : CLAUDE_KEYCHAIN_FALLBACK_ACCOUNT;
+}
+
+async function runSecurityCommand(args: string[]): Promise<string | null> {
   try {
-    const { stdout } = await execFileAsync(
-      "security",
-      ["find-generic-password", "-s", CLAUDE_KEYCHAIN_SERVICE, "-w"],
-      { timeout: CLAUDE_KEYCHAIN_TIMEOUT_MS },
-    );
-    const raw = stdout.trim();
-    if (!raw) return null;
-    return JSON.parse(raw);
+    const { stdout } = await execFileAsync("security", args, {
+      timeout: CLAUDE_KEYCHAIN_TIMEOUT_MS,
+    });
+    return stdout.trim() || null;
   } catch {
     return null;
   }
 }
 
+/** Read Claude Code's account-specific Keychain item, then try the legacy lookup. */
+export async function readClaudeKeychainCredentials(
+  run: ClaudeKeychainCommandRunner = runSecurityCommand,
+  account: string = claudeKeychainAccount(),
+): Promise<unknown | null> {
+  const lookups = [
+    ["find-generic-password", "-a", account, "-w", "-s", CLAUDE_KEYCHAIN_SERVICE],
+    ["find-generic-password", "-w", "-s", CLAUDE_KEYCHAIN_SERVICE],
+  ];
+
+  for (const args of lookups) {
+    const raw = await run(args);
+    if (!raw) continue;
+    let parsed: unknown;
+    try {
+      parsed = JSON.parse(raw);
+    } catch {
+      continue;
+    }
+    const creds = ClaudeCredentialsSchema.safeParse(parsed);
+    if (creds.success && creds.data.claudeAiOauth?.accessToken) return parsed;
+  }
+  return null;
+}
+
 export class ClaudeQuotaProvider implements ProviderUsageFetcher {
   readonly providerId = "claude";
   readonly displayName = "Claude";