Summary
Add a HarnessBench adapter for microsoft/playwright-mcp. Surfaced by the 2026-04-16 scout pass as one of three frameworks that cleanly clear the bar (>20k stars, Apache-2.0, active <90d, Chromium-driving, LLM-backed).
Scout snapshot
- stars: 30,927
- license: Apache-2.0
- language: TypeScript
- last_commit: 2026-04-16
- shape: MCP bridge exposing Chrome via accessibility snapshots; structurally close to
stagehand/.
Work to do
src/harnessbench/harnesses/playwright_mcp/spec.py — declare HarnessSpec (runtime: node, requires_credentials: none, container_isolation: dedicated).src/harnessbench/harnesses/playwright_mcp/Dockerfile — FROM clawbench/base:<ver> + RUN npm install -g @playwright/mcp@<pinned>.src/harnessbench/harnesses/playwright_mcp/setup.sh + run.sh — MCP stdio bridge wired to an LLM host inside the container.- Register in
pyproject.toml under [project.entry-points."clawbench.harnesses"].
- Smoke run on the bundled fixture case.
Notes
MCP stdio bridge means we need an MCP-capable LLM host inside the harness. Pattern mirrors stagehand's wrapper.
Summary
Add a HarnessBench adapter for microsoft/playwright-mcp. Surfaced by the 2026-04-16 scout pass as one of three frameworks that cleanly clear the bar (>20k stars, Apache-2.0, active <90d, Chromium-driving, LLM-backed).
Scout snapshot
stagehand/.Work to do
src/harnessbench/harnesses/playwright_mcp/spec.py— declareHarnessSpec(runtime: node, requires_credentials: none, container_isolation: dedicated).src/harnessbench/harnesses/playwright_mcp/Dockerfile—FROM clawbench/base:<ver>+RUN npm install -g @playwright/mcp@<pinned>.src/harnessbench/harnesses/playwright_mcp/setup.sh+run.sh— MCP stdio bridge wired to an LLM host inside the container.pyproject.tomlunder[project.entry-points."clawbench.harnesses"].Notes
MCP stdio bridge means we need an MCP-capable LLM host inside the harness. Pattern mirrors stagehand's wrapper.