Fetch Command Code models at startup

src/models.ts

@@ -0,0 +1,85 @@
+export const DEFAULT_MODELS_URL = "https://api.commandcode.ai/provider/v1/models"
+
+const DEFAULT_MAX_OUTPUT_TOKENS = 65_536
+
+interface ApiModel {
+  id: string
+  name: string
+  contextLength: number
+}
+
+export interface CommandCodeModel {
+  id: string
+  name: string
+  reasoning: boolean
+  contextWindow: number
+  maxTokens: number
+}
+
+interface FetchCommandCodeModelsOptions {
+  url?: string
+  fetchImpl?: typeof fetch
+}
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null
+}
+
+function stringField(record: Record<string, unknown>, key: string): string {
+  const value = record[key]
+  if (typeof value !== "string") throw new Error(`Expected ${key} to be a string`)
+  return value
+}
+
+function numberField(record: Record<string, unknown>, key: string): number {
+  const value = record[key]
+  if (typeof value !== "number") throw new Error(`Expected ${key} to be a number`)
+  return value
+}
+
+function parseApiModel(value: unknown): ApiModel {
+  if (!isRecord(value)) throw new Error("Expected model entry to be an object")
+
+  return {
+    id: stringField(value, "id"),
+    name: stringField(value, "name"),
+    contextLength: numberField(value, "context_length"),
+  }
+}
+
+export function commandCodeModelsFromApiResponse(value: unknown): readonly CommandCodeModel[] {
+  if (!isRecord(value)) throw new Error("Expected models response to be an object")
+  if (value.object !== "list") throw new Error("Expected models response object to be 'list'")
+
+  const data = value.data
+  if (!Array.isArray(data)) throw new Error("Expected models response data to be an array")
+
+  return data.map(parseApiModel).map((model) => ({
+    id: model.id,
+    name: `${model.name} (CC)`,
+    reasoning: true,
+    contextWindow: model.contextLength,
+    maxTokens: Math.min(model.contextLength, DEFAULT_MAX_OUTPUT_TOKENS),
+  }))
+}
+
+export async function fetchCommandCodeModels(
+  options: FetchCommandCodeModelsOptions = {},
+): Promise<readonly CommandCodeModel[]> {
+  const url = options.url ?? DEFAULT_MODELS_URL
+  const fetchImpl = options.fetchImpl ?? fetch
+  const response = await fetchImpl(url, {
+    headers: {
+      accept: "application/json",
+    },
+  })
+
+  if (!response.ok) {
+    throw new Error(
+      `Failed to fetch Command Code models: ${response.status} ${response.statusText}`,
+    )
+  }
+
+  const body: unknown = await response.json()
+  return commandCodeModelsFromApiResponse(body)
+}