apiKey in options is ignored when creating an agent

[farhadatwindmill]

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• Search existing issues to avoid duplicates

Environment Information

Please provide the following information to help us reproduce and resolve your issue:

Stagehand:

• Language/SDK: Typescript
• Stagehand version: 2.5.0

AI Provider:

• Provider: Anthropic
• Model: claude-sonnet-4-20250514

Issue Description

I'm using this piece of code

  const agent = stagehand.agent({
    provider: "anthropic",
    model: "claude-sonnet-4-20250514",
    instructions: "You are a helpful assistant that can use a web browser.",
    options: {
      apiKey: ANTHROPIC_API_KEY,
    },
  });

And i have this error:

StagehandError: API key not found for `anthropic` provider. Please set the ANTHROPIC_API_KEY environment variable or pass an apiKey in the options object.

I do not have the ANTHROPIC_API_KEY env var set as I do not want to set it, and it seems the apiKey I set in options is ignored.

It seems here is the faulty part in lib/index.ts:

        if (this.usingAPI) {
          if (!this.apiClient) {
            throw new StagehandNotInitializedError("API client");
          }

          if (!options.options) {
            options.options = {};
          }

          // HERE apiKey is overwritten even if initially set
          if (options.provider === "anthropic") {
            options.options.apiKey = process.env.ANTHROPIC_API_KEY;
          } else if (options.provider === "openai") {
            options.options.apiKey = process.env.OPENAI_API_KEY;
          } else if (options.provider === "google") {
            options.options.apiKey = process.env.GOOGLE_API_KEY;
          }

          if (!options.options.apiKey) {
            throw new StagehandError(
              `API key not found for \`${options.provider}\` provider. Please set the ${options.provider === "anthropic" ? "ANTHROPIC_API_KEY" : "OPENAI_API_KEY"} environment variable or pass an apiKey in the options object.`,
            );
          }

          return await this.apiClient.agentExecute(options, executeOptions);
        }

Steps to Reproduce

1. Do not set env var
2. Try the code above
3. See error

Minimal Reproduction Code

// there are multiple modes to add as header: //nobundling //native //npm //nodejs
// https://www.windmill.dev/docs/getting_started/scripts_quickstart/typescript#modes
//nodejs

// import { toWords } from "number-to-words@1"
import * as wmill from "windmill-client"
import { z } from "zod";
import { Stagehand } from "@browserbasehq/stagehand";
import { Browserbase } from "@browserbasehq/sdk";


// fill the type, or use the +Resource type to get a type-safe reference to a resource
// type Postgresql = object


async function main(url: string, instructions: string, sessionId?: string) {
  const BROWSERBASE_API_KEY = [...]
  const BROWSERBASE_PROJECT_ID = [...]
  const ANTHROPIC_API_KEY = [...]
  const OPENAI_API_KEY = [...]

  const bb = new Browserbase({
    apiKey: BROWSERBASE_API_KEY,
  });

  let session = null;
  if (!sessionId) {
    session = await bb.sessions.create({
      keepAlive: true,
      projectId: BROWSERBASE_PROJECT_ID,
    });
  }

  const actualSessionId = session ? session.id : sessionId;

  // Initialize Stagehand
  const stagehand = new Stagehand({
    env: "BROWSERBASE",
    apiKey: BROWSERBASE_API_KEY,
    projectId: BROWSERBASE_PROJECT_ID,
    modelName: "claude-sonnet-4-20250514",
    modelClientOptions: {
      apiKey: ANTHROPIC_API_KEY,
    },
    browserbaseSessionID: actualSessionId
  });
  await stagehand.init();
  const page = stagehand.page;
  await page.goto(url);

  const agent = stagehand.agent({
    provider: "anthropic",
    model: "claude-sonnet-4-20250514",
    instructions: "You are a helpful assistant that can use a web browser.",
    options: {
      apiKey: ANTHROPIC_API_KEY,
    },
  });

  await agent.execute(instructions);

  await stagehand.close();
  return 0
}

Error Messages / Log trace

StagehandError: API key not found for `anthropic` provider. Please set the ANTHROPIC_API_KEY environment variable or pass an apiKey in the options object.

Screenshots / Videos

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Related Issues

Are there any related issues or PRs?

• Related to: #[issue number]
• Duplicate of: #[issue number]
• Blocks: #[issue number]

[flancast90]

Same error here, actually using the exact code from the docs with Gemini