Before this change, the main skill served by the CLI (`agent-browser
skills get agent-browser`) was a ~40-line discovery stub whose content
was essentially "run `agent-browser skills get <name>` before doing
anything." Agents already inside the CLI got no signal from it — the
content they needed to actually use the tool lived only in the `--full`
references.
Split the two jobs apart:
- **`skill-data/core/`** (new) — the runtime usage guide. 420-line
`SKILL.md` covering the snapshot-and-ref loop, common workflows
(login, extract, screenshot, multi-tab, sessions, iframes, dialogs),
waiting strategies, element selection strategies, troubleshooting,
and when to load a specialized skill. Supplementary `references/` and
`templates/` (moved from `skills/agent-browser/`) provide the full
command reference under `--full`.
- **`skills/agent-browser/SKILL.md`** — still the discovery stub that
`npx skills add` installs, now marked `hidden: true` so it stays out
of `skills list` inside the CLI. Body is a clean pointer to
`agent-browser skills get core` and the specialized skills.
The `hidden: true` frontmatter flag is a new, general mechanism: skills
marked hidden are omitted from `skills list` and `skills get --all` but
can still be fetched by explicit name. This keeps the stub reachable
for anyone who installed via `npx skills add` without polluting the
CLI-side skill listing.
## Behavior
```
$ agent-browser skills list
agentcore Run agent-browser on AWS Bedrock AgentCore cloud browsers...
core Core agent-browser usage guide. Read this before running...
dogfood Systematically explore and test a web application...
electron Automate Electron desktop apps (VS Code, Slack, Discord...)
slack Interact with Slack workspaces using browser automation...
vercel-sandbox Run agent-browser + Chrome inside Vercel Sandbox microVMs...
$ agent-browser skills get core # the actual usage guide
# ~420 lines of workflows, patterns, troubleshooting
$ agent-browser skills get agent-browser # still works if called explicitly
# the thin stub, now pointing at `core`
```
External `npx skills add vercel-labs/agent-browser` behavior is
unchanged: it finds and installs the thin `agent-browser` stub, which
tells the agent to run `agent-browser skills get core` for real
content. Version drift protection is preserved — the stub is the only
thing that gets copied; the real content is always runtime-fetched.
## Updated
- `cli/src/skills.rs` — `SkillInfo.hidden: bool`, parsed from
frontmatter; `run_list` and `run_get --all` filter it. 3 new unit
tests for the frontmatter parser.
- `cli/src/output.rs` — top-level `--help` and `skills` subcommand help
reference `skills get core` / `skills get core --full`.
- `AGENTS.md` — "update these files for user-facing features" now
points at `skill-data/core/` instead of the stub, with a note that
the stub is not the right place for feature content.
- `README.md`, `docs/src/app/skills/page.mdx` — describe the new
split and `skills get core --full` as the recommended entry point.
- `evals/cases/{command-usage,skill-selection}.ts` — expect
`skills get core` in agent output instead of `skills get
agent-browser`. Eval lib still reads `skills/agent-browser/SKILL.md`
(simulating what an agent sees after `npx skills add`).
All 11 skills unit tests pass. `cargo clippy -- -D warnings` and
`cargo fmt --check` clean. Verified end-to-end: `skills list` shows
`core` + specialized (no stub), `skills get core` returns the new
content, `skills get agent-browser` still returns the stub on explicit
request.
3.3 KiB
3.3 KiB
Profiling
Capture Chrome DevTools performance profiles during browser automation for performance analysis.
Related: commands.md for full command reference, SKILL.md for quick start.
Contents
Basic Profiling
# Start profiling
agent-browser profiler start
# Perform actions
agent-browser navigate https://example.com
agent-browser click "#button"
agent-browser wait 1000
# Stop and save
agent-browser profiler stop ./trace.json
Profiler Commands
# Start profiling with default categories
agent-browser profiler start
# Start with custom trace categories
agent-browser profiler start --categories "devtools.timeline,v8.execute,blink.user_timing"
# Stop profiling and save to file
agent-browser profiler stop ./trace.json
Categories
The --categories flag accepts a comma-separated list of Chrome trace categories. Default categories include:
devtools.timeline-- standard DevTools performance tracesv8.execute-- time spent running JavaScriptblink-- renderer eventsblink.user_timing--performance.mark()/performance.measure()callslatencyInfo-- input-to-latency trackingrenderer.scheduler-- task scheduling and executiontoplevel-- broad-spectrum basic events
Several disabled-by-default-* categories are also included for detailed timeline, call stack, and V8 CPU profiling data.
Use Cases
Diagnosing Slow Page Loads
agent-browser profiler start
agent-browser navigate https://app.example.com
agent-browser wait --load networkidle
agent-browser profiler stop ./page-load-profile.json
Profiling User Interactions
agent-browser navigate https://app.example.com
agent-browser profiler start
agent-browser click "#submit"
agent-browser wait 2000
agent-browser profiler stop ./interaction-profile.json
CI Performance Regression Checks
#!/bin/bash
agent-browser profiler start
agent-browser navigate https://app.example.com
agent-browser wait --load networkidle
agent-browser profiler stop "./profiles/build-${BUILD_ID}.json"
Output Format
The output is a JSON file in Chrome Trace Event format:
{
"traceEvents": [
{ "cat": "devtools.timeline", "name": "RunTask", "ph": "X", "ts": 12345, "dur": 100, ... },
...
],
"metadata": {
"clock-domain": "LINUX_CLOCK_MONOTONIC"
}
}
The metadata.clock-domain field is set based on the host platform (Linux or macOS). On Windows it is omitted.
Viewing Profiles
Load the output JSON file in any of these tools:
- Chrome DevTools: Performance panel > Load profile (Ctrl+Shift+I > Performance)
- Perfetto UI: https://ui.perfetto.dev/ -- drag and drop the JSON file
- Trace Viewer:
chrome://tracingin any Chromium browser
Limitations
- Only works with Chromium-based browsers (Chrome, Edge). Not supported on Firefox or WebKit.
- Trace data accumulates in memory while profiling is active (capped at 5 million events). Stop profiling promptly after the area of interest.
- Data collection on stop has a 30-second timeout. If the browser is unresponsive, the stop command may fail.