Server-side caching not working for extract(), act(), observe()

[helmelwa]

--- Environment Information

Stagehand:

• Language/SDK: TypeScript
• Stagehand version: 3.1.0

AI Provider:

• Provider: OpenAI
• Model: gpt-4.1-mini

Browser:

• Browser Environment: Browserbase
• serverCache: true

---

Issue Description

Server-side caching does not work for extract(), act(), and
observe() methods despite documentation stating it should
work automatically when running on Browserbase.

Steps to Reproduce

1. Create new project with npx create-browser-app
2. Run with default config (env: "BROWSERBASE",
   serverCache: true)
3. Execute extract(), act(), or observe() call
4. Check cacheStatus - always returns "MISS"
5. Run same operation again - still "MISS"

Minimal Reproduction Code

import "dotenv/config";
import { Stagehand } from "@browserbasehq/stagehand";

const stagehand = new Stagehand({
env: "BROWSERBASE",
serverCache: true,
});

await stagehand.init();
const page = stagehand.context.pages()[0];

await page.goto("https://stagehand.dev");

// First call - always MISS
const extractResult = await stagehand.extract(
"Extract the value proposition from the page."
);
console.log(extractResult.cacheStatus); // "MISS"

// Second call with same URL and instruction - still MISS
const extractResult2 = await stagehand.extract(
"Extract the value proposition from the page."
);
console.log(extractResult2.cacheStatus); // "MISS"

Error Messages / Log trace

extract server cache miss
act server cache miss
observe server cache miss

All show cachedInputTokens: 0 and cacheStatus: "MISS" even
on repeated identical calls.

Additional Notes

• agent() does use caching (shows cached_input_tokens > 0)
• Documentation at
  https://docs.stagehand.dev/v3/best-practices/caching says
  server caching works for extract/act/observe but it doesn't
• This appears to be a bug in Stagehand v3.1.0