Functionize MCP server vs Selenium

Functionize MCP server

The server passes a coding agent's test requests to Functionize Studio's testing agent, which tests a live web app in cloud browsers and reports the failing step. It uses OAuth with read and write scopes and has a no-card free plan. Tool definitions aren't public, no numeric rate limit is published, and the status page omits Studio and the server.

Selenium

Selenium is stable, Apache-2.0 software on 4.51.0 with bindings in five languages, CI passing on trunk, an llms.txt and an agent guide added in September 2026. It has no MCP server of its own, Selenium Manager sends usage statistics by default, and Grid accepts unauthenticated sessions unless a username and password are set.

Functionize MCP server

1. Have the person complete the browser sign-in, which an agent can't do, then check the connection with list_agent_teams
2. Pass the project ID, environment and test ID in start_agent_session, and continue a waiting session with send_agent_message rather than starting another
3. Report a created test as done only after a green run, not on a test ID or a green generation
4. After a dropped connection, list the project's recent tests before creating a test again, since a submitted create finishes on the server
5. Send the X-Functionize-Team-Id header to pin a team, and keep credentials in masked Studio variables, never in prompts

Selenium

1. Install with pip install selenium (Python 3.10 or later) and let Selenium Manager fetch drivers. Do not set driver paths
2. Use WebDriverWait with expected conditions, never fixed sleeps, and do not mix implicit and explicit waits
3. Set SE_AVOID_STATS=true to stop Selenium Manager sending usage statistics
4. Point coding agents at https://www.selenium.dev/llms.txt. Most Selenium 2 and 3 era examples use removed APIs
5. Set --username and --password before exposing a Grid beyond localhost. Check http://localhost:4444/status before creating sessions