Q84: live model lists follow every page

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/main/services/provider-models-fetch.ts

@@ -9,30 +9,55 @@ import { getJson, type JsonRecord } from "./provider-http";
  * rather than falling back to a stale static list.
  */
 
+const MAX_MODEL_PAGES = 50;
+
 export function mapOpenAiModels(data: unknown): ProviderModelEntry[] {
-  return collectModels(data, (item, id) => ({ id, name: id }));
+  return collectModels(modelItems(data), (item, id) => ({ id, name: id }));
 }
 
 export function mapAnthropicModels(data: unknown): ProviderModelEntry[] {
-  return collectModels(data, (item, id) => ({
+  return collectModels(modelItems(data), (item, id) => ({
     id,
     name: typeof item.display_name === "string" && item.display_name.trim() ? item.display_name.trim() : id,
   }));
 }
 
+/** OpenAI-style lists come whole; one that says has_more is followed through OpenAI's `after` cursor. */
 export async function fetchOpenAiModels(modelsUrl: string, headers: Record<string, string>): Promise<ProviderModelEntry[]> {
-  const response = await getJson(modelsUrl, headers);
-  return mapOpenAiModels(response.data);
+  return mapOpenAiModels({ data: await fetchAllPages(modelsUrl, headers, (cursor) => withQuery(modelsUrl, { after: cursor })) });
 }
 
+/** Anthropic pages 20 models by default; ask for its largest page and follow `after_id` to the end. */
 export async function fetchAnthropicModels(modelsUrl: string, headers: Record<string, string>): Promise<ProviderModelEntry[]> {
-  const response = await getJson(modelsUrl, headers);
-  return mapAnthropicModels(response.data);
+  const first = withQuery(modelsUrl, { limit: "1000" });
+  return mapAnthropicModels({ data: await fetchAllPages(first, headers, (cursor) => withQuery(modelsUrl, { limit: "1000", after_id: cursor })) });
 }
 
-function collectModels(data: unknown, toEntry: (item: JsonRecord, id: string) => ProviderModelEntry): ProviderModelEntry[] {
-  const list = isRecord(data) && Array.isArray(data.data) ? data.data : null;
-  if (!list) throw new Error("Provider model list response was not in the expected shape.");
+async function fetchAllPages(firstUrl: string, headers: Record<string, string>, nextUrl: (cursor: string) => string): Promise<unknown[]> {
+  const items: unknown[] = [];
+  let url = firstUrl;
+  for (let page = 1; page <= MAX_MODEL_PAGES; page += 1) {
+    const { data } = await getJson(url, headers);
+    items.push(...modelItems(data));
+    if (!isRecord(data) || data.has_more !== true) return items;
+    if (typeof data.last_id !== "string" || !data.last_id) throw new Error("The provider said it has more models but no cursor to fetch them.");
+    url = nextUrl(data.last_id);
+  }
+  throw new Error(`The provider's model list ran past ${MAX_MODEL_PAGES} pages.`);
+}
+
+function withQuery(url: string, params: Record<string, string>): string {
+  const target = new URL(url);
+  for (const [name, value] of Object.entries(params)) target.searchParams.set(name, value);
+  return target.toString();
+}
+
+function modelItems(data: unknown): unknown[] {
+  if (!isRecord(data) || !Array.isArray(data.data)) throw new Error("Provider model list response was not in the expected shape.");
+  return data.data;
+}
+
+function collectModels(list: unknown[], toEntry: (item: JsonRecord, id: string) => ProviderModelEntry): ProviderModelEntry[] {
   const entries: ProviderModelEntry[] = [];
   const seen = new Set<string>();
   for (const item of list) {

tests/unit/provider-models-fetch.test.ts

@@ -1,8 +1,8 @@
 import { randomUUID } from "node:crypto";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
-import { describe, expect, test } from "vitest";
-import { mapAnthropicModels, mapOpenAiModels } from "../../src/main/services/provider-models-fetch";
+import { afterEach, describe, expect, test, vi } from "vitest";
+import { fetchAnthropicModels, fetchOpenAiModels, mapAnthropicModels, mapOpenAiModels } from "../../src/main/services/provider-models-fetch";
 import { DatabaseConnection } from "../../src/main/database/connection";
 import { ProviderService } from "../../src/main/services/provider-service";
 import { providerAdapters } from "../../src/main/services/provider-adapters";
@@ -56,3 +56,40 @@ describe("ProviderService.listModels routing", () => {
     connection.close();
   });
 });
+
+describe("live model lists follow every page", () => {
+  afterEach(() => vi.unstubAllGlobals());
+
+  function pages(byCursor: Record<string, Record<string, unknown>>, seen: string[]) {
+    vi.stubGlobal("fetch", async (url: string) => {
+      seen.push(url);
+      const cursor = new URL(url).searchParams.get("after_id") ?? new URL(url).searchParams.get("after") ?? "";
+      return new Response(JSON.stringify(byCursor[cursor]), { status: 200, headers: { "content-type": "application/json" } });
+    });
+  }
+
+  test("Anthropic pages through after_id at the largest page size until has_more is false", async () => {
+    const seen: string[] = [];
+    pages({
+      "": { data: [{ id: "claude-a", display_name: "A" }], has_more: true, last_id: "claude-a" },
+      "claude-a": { data: [{ id: "claude-b", display_name: "B" }], has_more: false, last_id: "claude-b" },
+    }, seen);
+    expect((await fetchAnthropicModels("https://api.anthropic.com/v1/models", {})).map((model) => model.id)).toEqual(["claude-a", "claude-b"]);
+    expect(seen).toEqual(["https://api.anthropic.com/v1/models?limit=1000", "https://api.anthropic.com/v1/models?limit=1000&after_id=claude-a"]);
+  });
+
+  test("an OpenAI-style list that says has_more is followed through after; one without it is whole", async () => {
+    const seen: string[] = [];
+    pages({
+      "": { data: [{ id: "m1" }], has_more: true, last_id: "m1" },
+      m1: { data: [{ id: "m2" }], has_more: false },
+    }, seen);
+    expect((await fetchOpenAiModels("https://api.example.test/v1/models", {})).map((model) => model.id)).toEqual(["m1", "m2"]);
+    expect(seen).toEqual(["https://api.example.test/v1/models", "https://api.example.test/v1/models?after=m1"]);
+  });
+
+  test("a page that says has_more without a cursor fails instead of returning part of the list", async () => {
+    pages({ "": { data: [{ id: "claude-a" }], has_more: true, last_id: null } }, []);
+    await expect(fetchAnthropicModels("https://api.anthropic.com/v1/models", {})).rejects.toThrow("more models but no cursor");
+  });
+});