test(usage): isolate the legacy login locator from inherited credentials

Keep the independently reproduced GLM discovery fix and isolate its file test from inherited XDG_CONFIG_HOME. Leave MiniMax quota routing for separate verification before changing existing API-key requests.

Co-authored-by: peanut_hzm <peanut_hzm@163.com>

plugins/zai-usage-source/server/usage.test.ts

@@ -1,4 +1,4 @@
-import { mkdtempSync, rmSync } from "node:fs";
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
@@ -32,11 +32,13 @@ describe("zai usage source", () => {
     process.env["USERPROFILE"] = homeDir;
     for (const key of [
       "APPDATA",
+      "XDG_CONFIG_HOME",
       "COPILOT_TOKEN",
       "GITHUB_TOKEN",
       "GITHUB_PAT",
       "CURSOR_ACCESS_TOKEN",
       "CURSOR_TOKEN",
+      "Z_AI_API_KEY",
       "ZAI_API_KEY",
       "GLM_API_KEY",
       "GROK_API_KEY",
@@ -116,11 +118,61 @@ describe("zai usage source", () => {
       details: expect.arrayContaining([{ id: "status", label: "Status", value: "VALID" }]),
     });
   });
-});
 
-it("discovery returns a locator when fetch finds zai credentials", async () => {
-  const previous = process.env["ZAI_API_KEY"];
-  try {
+  it("fetches Z.ai usage from Z_AI_API_KEY, the name the glm-acp-agent CLI uses", async () => {
+    process.env["Z_AI_API_KEY"] = "zai_cli_token";
+    let authorization: string | null = null;
+    fetchApi = (async (_url: RequestInfo | URL, init?: RequestInit) => {
+      authorization = (init?.headers as Record<string, string> | undefined)?.Authorization ?? null;
+      return jsonResponse({ data: [{ productName: "GLM Coding Max", status: "VALID" }] });
+    }) as unknown as typeof fetch;
+
+    const zai = findProvider(await service().listUsage(), "zai");
+
+    expect(authorization).toBe("Bearer zai_cli_token");
+    expect(zai).toMatchObject({ status: "available", planLabel: "GLM Coding Max" });
+  });
+
+  it("reads Z.ai usage from the credentials file the glm-acp-agent CLI writes", async () => {
+    const configDir = join(homeDir, ".config", "glm-acp-agent");
+    mkdirSync(configDir, { recursive: true });
+    writeFileSync(
+      join(configDir, "credentials.json"),
+      JSON.stringify({ z_ai_api_key: "zai_file_token" }),
+    );
+    let authorization: string | null = null;
+    fetchApi = (async (_url: RequestInfo | URL, init?: RequestInit) => {
+      authorization = (init?.headers as Record<string, string> | undefined)?.Authorization ?? null;
+      return jsonResponse({ data: [{ productName: "GLM Coding Max", status: "VALID" }] });
+    }) as unknown as typeof fetch;
+
+    const zai = findProvider(await service().listUsage(), "zai");
+
+    expect(authorization).toBe("Bearer zai_file_token");
+    expect(zai).toMatchObject({ status: "available" });
+  });
+
+  it("honours XDG_CONFIG_HOME for the credentials file", async () => {
+    const configDir = join(homeDir, "xdg", "glm-acp-agent");
+    mkdirSync(configDir, { recursive: true });
+    writeFileSync(
+      join(configDir, "credentials.json"),
+      JSON.stringify({ z_ai_api_key: "zai_xdg_token" }),
+    );
+    process.env["XDG_CONFIG_HOME"] = join(homeDir, "xdg");
+    let authorization: string | null = null;
+    fetchApi = (async (_url: RequestInfo | URL, init?: RequestInit) => {
+      authorization = (init?.headers as Record<string, string> | undefined)?.Authorization ?? null;
+      return jsonResponse({ data: [{ productName: "GLM Coding Max", status: "VALID" }] });
+    }) as unknown as typeof fetch;
+
+    const zai = findProvider(await service().listUsage(), "zai");
+
+    expect(authorization).toBe("Bearer zai_xdg_token");
+    expect(zai).toMatchObject({ status: "available" });
+  });
+
+  it("discovery returns a locator when fetch finds zai credentials", async () => {
     process.env["ZAI_API_KEY"] = "fixture-token";
     let requested = false;
     await fetchFirst(async () => {
@@ -131,10 +183,7 @@ it("discovery returns a locator when fetch finds zai credentials", async () => {
     expect(await discover()).toEqual([
       { key: "default", input: { store: "env", locator: "ZAI_API_KEY" } },
     ]);
-  } finally {
-    if (previous === undefined) delete process.env["ZAI_API_KEY"];
-    else process.env["ZAI_API_KEY"] = previous;
-  }
+  });
 });
 
 describe("account discovery", () => {

plugins/zai-usage-source/server/usage.ts

@@ -1,4 +1,7 @@
 import type { UsageInput } from "../shared/input.js";
+import { promises as fs } from "node:fs";
+import { homedir } from "node:os";
+import { join } from "node:path";
 import { z } from "zod";
 import {
   unavailable,
@@ -25,11 +28,16 @@ const ZaiUsageResponseSchema = z.object({
     .optional(),
 });
 
+/** The credentials file the `glm-acp-agent` CLI writes. */
+const ZaiCredentialsSchema = z.object({
+  z_ai_api_key: z.string().optional(),
+});
+
 export async function fetchUsage(
   input: UsageInput,
   fetchApi: typeof fetch = fetch,
 ): Promise<UsageReport> {
-  const token = process.env[input.locator];
+  const token = await readToken(input);
   if (!token) throw new Error("Z.ai login store no longer exists");
 
   const res = await fetchApi("https://api.z.ai/api/biz/subscription/list", {
@@ -64,9 +72,36 @@ export async function fetchUsage(
   };
 }
 
+/**
+ * The Z.AI API key comes from the environment or from the credentials file the
+ * `glm-acp-agent` CLI writes. The CLI names the variable `Z_AI_API_KEY`; the
+ * older `ZAI_API_KEY` spelling is still accepted.
+ */
+async function readToken(input: UsageInput): Promise<string | undefined> {
+  if (input.store === "env") {
+    return process.env[input.locator];
+  }
+  try {
+    const raw: unknown = JSON.parse(await fs.readFile(input.locator, "utf8"));
+    return ZaiCredentialsSchema.parse(raw).z_ai_api_key;
+  } catch {
+    return undefined;
+  }
+}
+
 export async function discover(): Promise<UsageAccount[]> {
-  for (const locator of ["ZAI_API_KEY", "GLM_API_KEY"]) {
+  for (const locator of ["Z_AI_API_KEY", "ZAI_API_KEY", "GLM_API_KEY"]) {
     if (process.env[locator]) return [{ key: "default", input: { store: "env", locator } }];
   }
+
+  const credentialsPath = join(
+    process.env.XDG_CONFIG_HOME || join(homedir(), ".config"),
+    "glm-acp-agent",
+    "credentials.json",
+  );
+  if (await readToken({ store: "file", locator: credentialsPath })) {
+    return [{ key: "default", input: { store: "file", locator: credentialsPath } }];
+  }
+
   return [];
 }

plugins/zai-usage-source/shared/input.ts

@@ -1,7 +1,7 @@
 import { z } from "zod";
 export const inputSchema = z
   .object({
-    store: z.literal("env"),
+    store: z.enum(["env", "file"]),
     locator: z.string().min(1),
   })
   .strict();