{"id":"mozilla-firefox-devtools-mcp","name":"firefox-devtools-mcp","af_score":64.2,"security_score":43.2,"reliability_score":33.8,"what_it_does":"Provides an MCP server that automates Mozilla Firefox via WebDriver BiDi using Selenium/WebDriver. Exposes MCP tools for navigating pages, interacting with elements by UID, capturing screenshots, handling network/console events, and optionally using privileged contexts (requires extra system access).","best_when":"You have a local machine with Firefox installed, want MCP-compatible browser control for agentic browsing/testing, and can accept running an automation browser session with optional privileged capabilities.","avoid_when":"You cannot run locally (no Firefox binary available), you need to avoid any form of JavaScript execution/privileged context access, or you require strict security governance over browser automation capabilities.","last_evaluated":"2026-03-30T13:48:53.224811+00:00","has_mcp":true,"has_api":false,"auth_methods":["None (local process transport via MCP client connection)","Environment-flag based capability enabling for privileged context/tools (e.g., MOZ_REMOTE_ALLOW_SYSTEM_ACCESS=1)"],"has_free_tier":false,"known_gotchas":["UID-based element actions can become stale after navigation; README recommends taking a fresh snapshot (take_snapshot) before UID tools.","In connect-existing mode, BiDi-dependent features (console/network events) are not available.","Privileged context tools require MOZ_REMOTE_ALLOW_SYSTEM_ACCESS=1; enabling them increases risk and may fail if not set correctly.","Windows sometimes requires invoking npx via cmd / appropriate command wrapper due to connection-closed errors.","Marionette must be enabled for connect-existing automation; leaving it enabled can alter fingerprint signals (bot detection risk)."],"error_quality":0.0}