4. API Key & Client Setup | Abhimanyu Aryan

The simplest path: read ANTHROPIC_API_KEY from the environment.

File: packages/ai/src/env-api-keys.ts L63-73

export function getEnvApiKey(provider: string): string | undefined {
  if (provider === "anthropic") {
    return process.env.ANTHROPIC_OAUTH_TOKEN || process.env.ANTHROPIC_API_KEY;
  }
  // ...other providers
}

Then create the Anthropic SDK client:

File: packages/ai/src/providers/anthropic.ts L622-637

import Anthropic from "@anthropic-ai/sdk";

const client = new Anthropic({
  apiKey,
  baseURL: model.baseUrl,
  dangerouslyAllowBrowser: true,
  defaultHeaders: {
    accept: "application/json",
    "anthropic-dangerous-direct-browser-access": "true",
    "anthropic-beta": "fine-grained-tool-streaming-2025-05-14",
  },
});

For your minimal harness, this is just:

import Anthropic from "@anthropic-ai/sdk";

const client = new Anthropic(); // reads ANTHROPIC_API_KEY automatically