feat(memory): add gemini embeddings + auto select providers

Co-authored-by: Gustavo Madeira Santana <gumadeiras@gmail.com>

src/memory/embeddings-openai.ts

@@ -0,0 +1,83 @@
+import { resolveApiKeyForProvider } from "../agents/model-auth.js";
+import type { EmbeddingProvider, EmbeddingProviderOptions } from "./embeddings.js";
+
+export type OpenAiEmbeddingClient = {
+  baseUrl: string;
+  headers: Record<string, string>;
+  model: string;
+};
+
+export const DEFAULT_OPENAI_EMBEDDING_MODEL = "text-embedding-3-small";
+const DEFAULT_OPENAI_BASE_URL = "https://api.openai.com/v1";
+
+export function normalizeOpenAiModel(model: string): string {
+  const trimmed = model.trim();
+  if (!trimmed) return DEFAULT_OPENAI_EMBEDDING_MODEL;
+  if (trimmed.startsWith("openai/")) return trimmed.slice("openai/".length);
+  return trimmed;
+}
+
+export async function createOpenAiEmbeddingProvider(
+  options: EmbeddingProviderOptions,
+): Promise<{ provider: EmbeddingProvider; client: OpenAiEmbeddingClient }> {
+  const client = await resolveOpenAiEmbeddingClient(options);
+  const url = `${client.baseUrl.replace(/\/$/, "")}/embeddings`;
+
+  const embed = async (input: string[]): Promise<number[][]> => {
+    if (input.length === 0) return [];
+    const res = await fetch(url, {
+      method: "POST",
+      headers: client.headers,
+      body: JSON.stringify({ model: client.model, input }),
+    });
+    if (!res.ok) {
+      const text = await res.text();
+      throw new Error(`openai embeddings failed: ${res.status} ${text}`);
+    }
+    const payload = (await res.json()) as {
+      data?: Array<{ embedding?: number[] }>;
+    };
+    const data = payload.data ?? [];
+    return data.map((entry) => entry.embedding ?? []);
+  };
+
+  return {
+    provider: {
+      id: "openai",
+      model: client.model,
+      embedQuery: async (text) => {
+        const [vec] = await embed([text]);
+        return vec ?? [];
+      },
+      embedBatch: embed,
+    },
+    client,
+  };
+}
+
+export async function resolveOpenAiEmbeddingClient(
+  options: EmbeddingProviderOptions,
+): Promise<OpenAiEmbeddingClient> {
+  const remote = options.remote;
+  const remoteApiKey = remote?.apiKey?.trim();
+  const remoteBaseUrl = remote?.baseUrl?.trim();
+
+  const { apiKey } = remoteApiKey
+    ? { apiKey: remoteApiKey }
+    : await resolveApiKeyForProvider({
+        provider: "openai",
+        cfg: options.config,
+        agentDir: options.agentDir,
+      });
+
+  const providerConfig = options.config.models?.providers?.openai;
+  const baseUrl = remoteBaseUrl || providerConfig?.baseUrl?.trim() || DEFAULT_OPENAI_BASE_URL;
+  const headerOverrides = Object.assign({}, providerConfig?.headers, remote?.headers);
+  const headers: Record<string, string> = {
+    "Content-Type": "application/json",
+    Authorization: `Bearer ${apiKey}`,
+    ...headerOverrides,
+  };
+  const model = normalizeOpenAiModel(options.model);
+  return { baseUrl, headers, model };
+}