feat(costs): add billing, quota, and budget control plane

packages/adapter-utils/src/billing.test.ts

@@ -0,0 +1,28 @@
+import { describe, expect, it } from "vitest";
+import { inferOpenAiCompatibleBiller } from "./billing.js";
+
+describe("inferOpenAiCompatibleBiller", () => {
+  it("returns openrouter when OPENROUTER_API_KEY is present", () => {
+    expect(
+      inferOpenAiCompatibleBiller({ OPENROUTER_API_KEY: "sk-or-123" } as NodeJS.ProcessEnv, "openai"),
+    ).toBe("openrouter");
+  });
+
+  it("returns openrouter when OPENAI_BASE_URL points at OpenRouter", () => {
+    expect(
+      inferOpenAiCompatibleBiller(
+        { OPENAI_BASE_URL: "https://openrouter.ai/api/v1" } as NodeJS.ProcessEnv,
+        "openai",
+      ),
+    ).toBe("openrouter");
+  });
+
+  it("returns fallback when no OpenRouter markers are present", () => {
+    expect(
+      inferOpenAiCompatibleBiller(
+        { OPENAI_BASE_URL: "https://api.openai.com/v1" } as NodeJS.ProcessEnv,
+        "openai",
+      ),
+    ).toBe("openai");
+  });
+});