Initial commit

Signed-off-by: Ilan Bigio <ilan@openai.com>

codex-cli/src/utils/model-utils.ts

@@ -0,0 +1,91 @@
+import { OPENAI_API_KEY } from "./config";
+import OpenAI from "openai";
+
+export const RECOMMENDED_MODELS: Array<string> = ["o4-mini", "o3"];
+
+/**
+ * Background model loader / cache.
+ *
+ * We start fetching the list of available models from OpenAI once the CLI
+ * enters interactive mode.  The request is made exactly once during the
+ * lifetime of the process and the results are cached for subsequent calls.
+ */
+
+let modelsPromise: Promise<Array<string>> | null = null;
+
+async function fetchModels(): Promise<Array<string>> {
+  // If the user has not configured an API key we cannot hit the network
+  if (!OPENAI_API_KEY) {
+    return ["o4-mini"];
+  }
+
+  try {
+    const openai = new OpenAI({ apiKey: OPENAI_API_KEY });
+    const list = await openai.models.list();
+
+    const models: Array<string> = [];
+    for await (const model of list as AsyncIterable<{ id?: string }>) {
+      if (model && typeof model.id === "string") {
+        models.push(model.id);
+      }
+    }
+
+    return models.sort();
+  } catch {
+    return [];
+  }
+}
+
+export function preloadModels(): void {
+  if (!modelsPromise) {
+    // Fire‑and‑forget – callers that truly need the list should `await`
+    // `getAvailableModels()` instead.
+    void getAvailableModels();
+  }
+}
+
+export async function getAvailableModels(): Promise<Array<string>> {
+  if (!modelsPromise) {
+    modelsPromise = fetchModels();
+  }
+  return modelsPromise;
+}
+
+/**
+ * Verify that the provided model identifier is present in the set returned by
+ * {@link getAvailableModels}. The list of models is fetched from the OpenAI
+ * `/models` endpoint the first time it is required and then cached in‑process.
+ */
+export async function isModelSupportedForResponses(
+  model: string | undefined | null,
+): Promise<boolean> {
+  if (
+    typeof model !== "string" ||
+    model.trim() === "" ||
+    RECOMMENDED_MODELS.includes(model)
+  ) {
+    return true;
+  }
+
+  const MODEL_LIST_TIMEOUT_MS = 2_000;
+
+  try {
+    const models = await Promise.race<Array<string>>([
+      getAvailableModels(),
+      new Promise<Array<string>>((resolve) =>
+        setTimeout(() => resolve([]), MODEL_LIST_TIMEOUT_MS),
+      ),
+    ]);
+
+    // If the timeout fired we get an empty list → treat as supported to avoid
+    // false negatives.
+    if (models.length === 0) {
+      return true;
+    }
+
+    return models.includes(model.trim());
+  } catch {
+    // Network or library failure → don't block start‑up.
+    return true;
+  }
+}