Hit this today and it was destroying my laptop. After tracing it down, the culprit was expect-cli mcp leaving behind a stale Playwright/browser-mcp process tree with a bunch of orphaned Chromium GPU processes and ffmpeg recorders. This was being spawned by codex cli processes. All of the codex processes had been shut down, but these expect processes were left behind.
What I found on macOS:
- multiple
chrome-headless-shell --type=gpu-process processes sitting around for 1h+ at roughly 150-400% CPU each
- several
ffmpeg-mac processes also still running
- parent process was
.../expect-cli/dist/browser-mcp.js
- one stale
browser-mcp.js process had become orphaned under launchd, while a fresh expect-cli helper had already restarted separately
This is the kind of tree I was seeing:
npm exec expect-cli@latest mcpnode .../.bin/expect-cli mcpnode .../expect-cli/dist/browser-mcp.jschrome-headless-shellchrome-headless-shell --type=gpu-processffmpeg-mac
Before cleanup the machine was basically pinned:
- load avg spiked over 80
- CPU idle was effectively 0%
- after killing the orphaned
browser-mcp parent and its Chromium/ffmpeg children, CPU went back to ~81% idle and the machine cooled off right away
Feels like the MCP/browser layer is not reliably cleaning up Playwright browser/video processes when a session exits, restarts, or gets detached.
If it helps, the hot Chromium processes were all running with flags like --headless --use-gl=angle --use-angle=swiftshader --enable-webgl.
Happy to grab more info if there’s a specific log or repro path you want.
Hit this today and it was destroying my laptop. After tracing it down, the culprit was
expect-cli mcpleaving behind a stale Playwright/browser-mcp process tree with a bunch of orphaned Chromium GPU processes and ffmpeg recorders. This was being spawned by codex cli processes. All of the codex processes had been shut down, but these expect processes were left behind.What I found on macOS:
chrome-headless-shell --type=gpu-processprocesses sitting around for 1h+ at roughly 150-400% CPU eachffmpeg-macprocesses also still running.../expect-cli/dist/browser-mcp.jsbrowser-mcp.jsprocess had become orphaned underlaunchd, while a freshexpect-clihelper had already restarted separatelyThis is the kind of tree I was seeing:
npm exec expect-cli@latest mcpnode .../.bin/expect-cli mcpnode .../expect-cli/dist/browser-mcp.jschrome-headless-shellchrome-headless-shell --type=gpu-processffmpeg-macBefore cleanup the machine was basically pinned:
browser-mcpparent and its Chromium/ffmpeg children, CPU went back to ~81% idle and the machine cooled off right awayFeels like the MCP/browser layer is not reliably cleaning up Playwright browser/video processes when a session exits, restarts, or gets detached.
If it helps, the hot Chromium processes were all running with flags like
--headless --use-gl=angle --use-angle=swiftshader --enable-webgl.Happy to grab more info if there’s a specific log or repro path you want.