#FAQ

#Is ferridriver production-ready?

It is pre-1.0. The browser API mirrors Playwright closely and the test suite is comprehensive across all four backends, but breaking changes between minor versions are expected until 1.0. Read the CHANGELOG before upgrading.

#Why "ferridriver"?

Ferris (the Rust mascot) + driver (browser driver). One word, no hyphen.

#Why not just use Playwright via NAPI / FFI?

Two reasons:

1. Playwright's core is TypeScript running in Node. Calling it from Rust still requires Node and an IPC hop. ferridriver runs the protocol in Rust directly — no second runtime.
2. The hot paths (auto-wait polling, selector compilation, retry loops) stay in Rust. From JavaScript via @ferridriver/node, you pay one NAPI call per assertion, not one per poll iteration.

#How does ferridriver compare to thirtyfour / fantoccini?

thirtyfour and fantoccini are W3C WebDriver clients in Rust. ferridriver speaks CDP, BiDi, and Playwright's WebKit Inspector protocol directly — no WebDriver server in between. Different layer of the stack, more features (auto-wait, network mocking, traces, video, strict locators), more browsers (Playwright WebKit), more shapes (test runner, BDD, MCP, NAPI binding).

If you're integrating with an existing Selenium Grid, use thirtyfour. If you're building a new browser-test setup, use ferridriver.

#Can I use ferridriver from Python / Java / Go?

Not directly. There is no Python or Java binding today. The Rust library is documented at docs.rs — a binding shouldn't be hard to write, but it's not on our roadmap.

For Node and Bun: @ferridriver/node exists.

#How do I run the test suite for multiple browsers in parallel?

Define one project per browser (see Configuration → Projects) and shard each project in CI. --project chromium --shard 1/4 on one job, --project firefox --shard 1/4 on another, etc.

#Does ferridriver work in Docker?

Yes. The official base images are not yet published, but anything that runs Chromium headless works. Make sure to install browser system dependencies in the image:

FROM rust:1.91-slim
RUN apt-get update && apt-get install -y \
    libnss3 libnspr4 libatk1.0-0 libatk-bridge2.0-0 libcups2 \
    libdrm2 libxkbcommon0 libxcomposite1 libxdamage1 libxfixes3 \
    libxrandr2 libgbm1 libpango-1.0-0 libcairo2 libasound2 \
    && rm -rf /var/lib/apt/lists/*

RUN cargo install ferridriver-cli --locked
RUN ferridriver install chromium

(ferridriver install --with-deps chromium does the same.)

#Can I drive an existing Chrome window?

Yes, with the cdp-raw backend:

# Start Chrome with remote debugging
google-chrome --remote-debugging-port=9222

# Connect
ferridriver mcp --connect ws://localhost:9222/devtools/browser/...

Or programmatically:

use ferridriver::browser_type::chromium;

let browser = chromium()
    .connect("ws://localhost:9222/devtools/browser/...", Default::default())
    .await?;

#How do I capture network traffic for a test?

Set the HAR record option on the context:

[test.browser.useOptions.recordHar]
path    = "test-results/network.har"
content = "embed"

The HAR file is written when the context closes. Inspect it with any HAR viewer (Chrome DevTools "Import HAR…", har tool, etc.).

Note: the BiDi backend does not support HAR.

#Does the MCP server work with Claude Code?

Yes:

claude mcp add ferridriver -- ferridriver mcp

Then ask Claude to navigate, take a screenshot, or run a script. See MCP setup for Claude Desktop, Cursor, and HTTP transport.

#Can I write BDD steps in Rust and JavaScript in the same suite?

Yes. Rust step macros and the JS / TS step bundle register into one registry. A single .feature file can mix steps defined in either — the runner picks the matching step regardless of source language.

#Is the API stable across minor versions?

Not yet. 0.x → 0.x+1 may include breaking changes. The CHANGELOG calls them out. We will commit to semver compatibility starting at 1.0.0.

#Where do I report bugs?

https://github.com/salamaashoush/ferridriver/issues

Include:

• ferridriver --version
• rustc --version
• OS and architecture
• Output of ferridriver -vv ... reproducing the failure
• A minimal repro (a single .feature file or a 10-line Rust test)

#How do I contribute?

See CONTRIBUTING. PRs welcome — start with a draft that explains the problem before you write much code.