diff --git a/package.json b/package.json
index acc1cec..72b5201 100644
--- a/package.json
+++ b/package.json
@@ -4,6 +4,9 @@
   "description": "The official Requesty extension for the Pi Coding Agent",
   "type": "module",
   "main": "requesty.js",
+  "scripts": {
+    "test": "node --test"
+  },
   "keywords": ["pi-package", "pi", "pi-coding-agent", "pi-extensions", "requesty", "openai-compatible", "models"],
   "license": "MIT",
   "peerDependencies": {
diff --git a/requesty.js b/requesty.js
index 5ab8906..c918f22 100644
--- a/requesty.js
+++ b/requesty.js
@@ -9,10 +9,15 @@ const DEFAULT_NAME = "Requesty";
 const DEFAULT_CONTEXT_WINDOW = 128000;
 const DEFAULT_MAX_TOKENS = 4096;
 
-function normalizeBaseUrl(baseUrl) {
+export function normalizeBaseUrl(baseUrl) {
   return baseUrl.replace(/\/+$/, "");
 }
 
+export function modelsUrl(baseUrl) {
+  const base = normalizeBaseUrl(baseUrl);
+  return /\/v\d+$/.test(base) ? `${base}/models` : `${base}/v1/models`;
+}
+
 function readModelsJson() {
   if (!fs.existsSync(MODELS_JSON_PATH)) {
     throw new Error(`${MODELS_JSON_PATH} does not exist`);
@@ -56,7 +61,7 @@ function getRequestyConfig() {
 }
 
 async function discoverModels(provider) {
-  const response = await fetch(`${provider.baseUrl}/models`, {
+  const response = await fetch(modelsUrl(provider.baseUrl), {
     headers: { Authorization: `Bearer ${provider.apiKey}` },
   });
 
diff --git a/requesty.test.js b/requesty.test.js
new file mode 100644
index 0000000..e5f41fc
--- /dev/null
+++ b/requesty.test.js
@@ -0,0 +1,35 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { modelsUrl, normalizeBaseUrl } from "./requesty.js";
+
+test("normalizeBaseUrl strips trailing slashes", () => {
+  const cases = [
+    ["https://router.requesty.ai", "https://router.requesty.ai"],
+    ["https://router.requesty.ai/", "https://router.requesty.ai"],
+    ["https://router.requesty.ai///", "https://router.requesty.ai"],
+    ["https://router.requesty.ai/v1", "https://router.requesty.ai/v1"],
+    ["https://router.requesty.ai/v1/", "https://router.requesty.ai/v1"],
+  ];
+
+  for (const [input, expected] of cases) {
+    assert.equal(normalizeBaseUrl(input), expected);
+  }
+});
+
+test("modelsUrl always resolves to a single /v1/models endpoint", () => {
+  const cases = [
+    // Anthropic Messages config: baseUrl has no version segment.
+    ["https://router.requesty.ai", "https://router.requesty.ai/v1/models"],
+    ["https://router.requesty.ai/", "https://router.requesty.ai/v1/models"],
+    // OpenAI Completions config: baseUrl already ends with a version segment.
+    ["https://router.requesty.ai/v1", "https://router.requesty.ai/v1/models"],
+    ["https://router.requesty.ai/v1/", "https://router.requesty.ai/v1/models"],
+    // Other version segments are respected rather than doubled up.
+    ["https://router.requesty.ai/v2", "https://router.requesty.ai/v2/models"],
+  ];
+
+  for (const [input, expected] of cases) {
+    assert.equal(modelsUrl(input), expected);
+  }
+});