SlyBrowser for Python

The default launch() backend is SlyBrowser's project-built W3C WebDriver. Place chromedriver.exe (chromedriver on Unix) beside the browser, pass driver_executable=..., or set SLYBROWSER_WEBDRIVER_PATH.

from slybrowser import launch

with launch(browser_executable, short_lived_lease, humanize=True) as browser:
    browser.get("https://example.test")
    print(browser.title)

The SDK never downloads or selects another driver. Install the optional Playwright adapter with pip install slybrowser[playwright] and call launch_playwright(...) only when that transport is explicitly required. Production packages require the exact hash-matched browser and driver as sibling files, and each process consumes a separate temporary copy of the short-lived signed lease. Humanize for the default path executes natively in Sly WebDriver.

Playwright adapter

from playwright.sync_api import sync_playwright
from slybrowser import launch_playwright

with sync_playwright() as playwright:
    browser = launch_playwright(
        playwright,
        browser_executable,
        short_lived_lease,
        framework_version="1.62.0",
    )

The adapter forces the authorized SlyBrowser executable, rejects Playwright's own browser path, and validates the binding line. launch_playwright_async, launch_playwright_persistent and its async equivalent follow the same contract. When humanize=True is set, the SDK writes a short-lived --sly-humanize-config native control file for the browser process. The Python SDK does not install a Playwright-side movement substitute; unsupported browser builds must fail closed at the native capability gate.

Install and launch the latest authorized release

Current release archives use 7z. Install 7z (or 7zz on Unix-like systems), or set SLYBROWSER_7Z_PATH to the executable before using the automatic installer.

launch_latest() reserves one plan slot, verifies the signed short lease and latest compatible Stable manifest, downloads the protected ZIP, validates both runtime executables and maintains a heartbeat until the browser closes.

from playwright.sync_api import sync_playwright
from slybrowser import launch_latest, launch_latest_playwright

with launch_latest(
    "account.authorization.json",
    license_trusted_keys={"license-prod-v1": license_public_key},
    release_trusted_keys={"release-prod-v1": release_public_key},
    humanize=True,
) as browser:
    print(browser.license_runtime)
    browser.get("https://example.test")

with sync_playwright() as playwright:
    browser = launch_latest_playwright(
        playwright,
        "account.authorization.json",
        license_trusted_keys={"license-prod-v1": license_public_key},
        release_trusted_keys={"release-prod-v1": release_public_key},
        framework_version="1.62.0",
    )
    try:
        print(browser.license_runtime["versionAudit"])
    finally:
        browser.close()

The authorized Playwright launchers reserve and release the same concurrency slot as launch_latest(...), expose license_runtime["versionAudit"], and fail closed if Playwright reports a launched browser version that does not exactly match the signed selected release. Use launch_latest_playwright_persistent(...), launch_latest_playwright_async(...) or launch_latest_playwright_persistent_async(...) for the matching profile and runtime style.

For the CLI, provide base64url raw 32-byte Ed25519 keys through SLYBROWSER_LICENSE_PUBLIC_KEYS_JSON and SLYBROWSER_RELEASE_PUBLIC_KEYS_JSON, then run:

slybrowser install --authorization account.authorization.json [--cache DIR] [--kernel-major 150|latest] [--update-kernel]

Import a paid license file on Windows

After checkout, import the encrypted v2 license file once on the Windows machine that will run SlyBrowser:

set SLYBROWSER_LICENSE_FILE_PUBLIC_KEYS_JSON={"license-file-prod-v1":"BASE64URL_RAW_ED25519_PUBLIC_KEY"}
slybrowser license import --input account.slybrowser-license.json --output account.slybrowser-sealed-license.json --passphrase YOUR_PASSPHRASE

The sealed file uses Windows DPAPI current-user protection and can be used anywhere an authorization file is accepted, including launch_latest(...) and the authorized Playwright helpers. You do not need to pass the license-file passphrase again, but the sealed file is still a local credential and must not be committed, logged, or shared.

Redacted license diagnostics

Use license info when a customer needs support without exposing their credential:

slybrowser license info --authorization account.slybrowser-sealed-license.json [--kernel-major 150|latest] [--update-kernel]

The command contacts the authorization service through Authorization: License ... and prints only redacted diagnostics: plan, effective plan, paid-through time, feature set, active/available browser-process concurrency, selected release state, update availability and stableErrorCode. It does not print the license key, session tokens, download tickets, email, PayNow identifiers, profile paths or service access URL.

Without --update-kernel, the CLI keeps updates closed: it reuses the current authorized local candidate when one exists and asks the service for an exact grant. Use --update-kernel to actively move to the newest authorized Stable release in the selected major range.

The authorization file is a credential and must not be committed or logged. See docs/authorized-release-service.md for the public authorization and release flow.