Agent Performance Lab

Agent Performance Lab is a local-first Chrome DevTools extension for browser-first testing and observability for AI agents.

It records opt-in browser sessions, shows tool-like activity and network metadata, scores governance and quality signals, and turns useful sessions into repeatable local baselines and private eval suites.

Availability

Chrome Web Store approval pending. The extension beta package has been built and submitted preparation is underway while the publisher account is reviewed.

What it helps teams measure

• Agent run timeline, prompts, visible responses, and browser-observable events.
• Tool-like activity, possible MCP activity, network metadata, retries, and latency signals.
• Local governance findings for risky prompts, secrets, sensitive data, and unknown destinations.
• Quality score, insights, Markdown reports, portable JSON evidence, baselines, and private eval suites.

Beta install flow

1. Install from the Chrome Web Store once the beta listing is approved.
2. Open a browser-based agent page.
3. Open Chrome DevTools and select the Agent Lab panel.
4. Start recording, run the workflow, stop recording, then review Timeline, Tools, Network, Governance, Insights, Lab, Export, and Settings.

Privacy model

Agent Performance Lab is local-first. It stores recordings, reports, settings, baselines, and private eval suites locally in the browser. The extension does not send recorded sessions, prompts, responses, network metadata, or private evals to an external server.

Read the full AssertHive Privacy Policy for Chrome Web Store disclosure details.

Chrome Web Store privacy disclosure

Agent Performance Lab uses handled data only for browser-based AI agent observability, testing, governance, scoring, reporting, and repeatable local eval creation. Recording is opt-in and local-first.

The extension may handle browser-visible Website content, Personal communications, Web history, User activity, Authentication information, Personally identifiable information, and workflow-specific financial, health, or location information when users choose to record pages containing that data.

The extension does not upload, sell, transfer, or share recorded user data with external servers or third parties. Users can stop recording, clear local data, and disable DOM text or network metadata capture in settings.

Current beta limits

Browser mode sees what Chrome and the inspected page expose. Hidden backend model calls, server-side MCP calls, and exact token usage may be incomplete unless the agent platform exposes that data to the browser.