Agent skill · software engineering · microsoft
chat-perf
Run chat perf benchmarks and memory leak checks against the local dev build or any published VS Code version. Use when investigating chat rendering regressions, validating perf-sensitive changes to chat UI, or checking for memory leaks in the chat response pipeline.
Why this skill is useful
Adds executable scripts for performance regression testing and memory leak checks that enhance the AI's capabilities in benchmarking chat UI.
What it needs
Requires npm installed locally. About 11k tokens when loaded. Last updated 2026-08-07. 188,455 stars on the source repository.
What this skill does
Chat Performance Testing When to use Before/after modifying chat rendering code (chatListRenderer.ts, chatInputPart.ts, markdown rendering) When changing the streaming response pipeline or SSE processing When modifying disposable/lifecycle patterns in chat components To compare performance between two VS Code releases In CI to gate PRs that touch chat UI code Quick start Perf regression test Script: scripts/chat-simulation/test-chat-perf-regression.js npm: pnpm run perf:chat Launches VS Code via Playwright Electron, opens the chat panel, sends a message with a mock LLM response, and measures timing, layout, and rendering metrics. By default, downloads VS Code 1.115.0 as a baseline, benchmarks it, then benchmarks the local dev build and compares. You don't always need a baseline. A baseline exists only for comparison (regression detection). If you just want the current build's numbers — profiling a single change, capturing traces/heap snapshots, or iterating on a scenario — pass --no-baseline to skip downloading and benchmarking the baseline entirely (roughly halves runtime). Baseline comparison is what turns raw measurements into a pass/fail verdict; without it you still get all the metrics, just no verdict. Key flags Flag Default Description --- --- --- --runs <n> 5 Runs per scenario. More = more stable. Use 5+ for CI. --scenario <id> / -s all Scenario to test (repeatable). See common/perf-scenarios.js. --build <path\ ver> / -b local dev Build to test. Accepts path or version (1.110.0, insiders, commit hash). --baseline <path> — Compare against a previously saved baseline JSON file. --baseline-build <path\ ver> 1.115.0 Version or local path to benchmark as baseline. --no-baseline — Skip the baseline entirely — just measure the test build (no download, no comparison, ~2× faster). Use when you only need raw numbers, not a regression verdict. --save-baseline — Save results as the new baseline (requires --baseline <path>). …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills microsoft/chat-perf