String Web Access API
API Reference

GET /wss

Upgrade to a WebSocket CDP browser session.

Opens a WebSocket connection to a remote Chrome DevTools Protocol (CDP) browser. The HTTP connection is upgraded to a WebSocket, providing a CDP interface for automation libraries like Puppeteer and Playwright.

wss://request.usestring.ai/v1/wss

Authentication

Pass your API key as an Authorization: Bearer header when establishing the connection.

Query parameters

Both parameters are optional and are passed on the connect URL:

wss://request.usestring.ai/v1/wss?proxy=standard&countryCode=DE
ParameterDefaultDescription
proxypremiumProxy tier for the session's traffic: premium (residential) or standard (datacenter, billed at half the premium bandwidth rate — see Browser pricing).
countryCodeUSISO 3166-1 alpha-2 country code the session's traffic exits from. Validated against the same country list as /fetch and normalized to uppercase.

An invalid value — or an unrecognized parameter — rejects the connection after the upgrade with WebSocket close code 1008 and the validation error as the close reason; no session is opened and nothing is billed.

Status codes

StatusMeaning
101WebSocket connection established; the HTTP connection is upgraded to CDP.
401Missing or invalid API key.
402Insufficient account balance.
404WebSocket upgrade attempted on an invalid path.

Session limits

A session is forcefully closed 30 minutes after it opens, or after 5 minutes of inactivity, whichever comes first — reconnect to continue. A bandwidth cap also applies. See Session limits.

Usage

See Connect with Puppeteer and Connect with Playwright for full examples, and Browser pricing for how sessions are billed.