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The local (alias Chrome-Local) backend launches a Chromium controlled by Playwright on the same machine running bubench. It’s the default for development, low-volume runs, and any case where you don’t need a cloud session.
The local browser does NOT inherit your operating-system or shell proxy. If you have clash/v2ray/Surge running and you can browse bloomberg.com in your everyday Chrome, the bench’s launched Chromium still bypasses the tunnel by default — until you set local_proxy_server below. Failing to do so silently produces net::ERR_CONNECTION_RESET / ERR_CONNECTION_TIMED_OUT on sites that need a tunnel, and the agent will look like it failed for “model” reasons.

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Configuration

Under any agent that supports browser_id: local, add the proxy fields: 
# config.yaml
agents:
  skyvern:
    browser:
      browser_id: local
      headless: false
      # Optional proxy. Empty server == no proxy (direct connection).
      local_proxy_server: "http://127.0.0.1:7890"   # clash default; v2ray often 1087/10809; SOCKS scheme socks5://...
      # local_proxy_username: ""                    # optional auth
      # local_proxy_password: ""
      # local_proxy_bypass: "127.0.0.1,localhost,*.local"
FieldTypeDefaultNotes
local_proxy_serverstring"" (no proxy)Full URL: http(s)://host:port or socks5://host:port
local_proxy_usernamestring—Optional auth username
local_proxy_passwordstring—Optional auth password
local_proxy_bypassstring—Comma-separated hosts/patterns to bypass the proxy

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Agent Support Matrix

Agentlocal_proxy_* honoured?How
skyvern✅ YesPasses --proxy-server=... (and --proxy-bypass-list=... if set) directly via args to Skyvern.launch_local_browser(). Note: bench uses Skyvern’s library-mode launch which bypasses Skyvern’s own setup_proxy() / HOSTED_PROXY_POOL env vars, so the Chrome flag is the working path
browser-use✅ YesConstructs browser_use.browser.profile.ProxySettings and passes it to the SDK’s Browser(...)
Agent-TARS❌ No (warns)The agent-tars CLI launches Chromium itself and exposes no proxy flag. Bench logs a one-time WARNING when configured
claude-code❌ No (warns)Delegates to @playwright/mcp; no proxy passthrough today. Same WARNING
openai-cua❌ No (warns)Same WARNING
deepbrowse❌ No (warns)Same WARNING
For the unsupported agents, the recommendation is to switch to the cloud backend — see Lexmount Cloud Browser. Lexmount sessions egress from outside mainland China (international region) so most “GFW-blocked” sites are reachable without any local proxy on your side.

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Security Note: Credentials in Chrome Process Args

For the skyvern agent, local_proxy_username / local_proxy_password are URL-encoded into the proxy URL and passed to Chrome via --proxy-server=http://user:pass@host:port. Chrome process args are visible to anyone running ps -ef (Linux) or ps auxe (macOS) on the box. If your proxy password is sensitive (e.g. shared corporate credentials), prefer one of:
  • Run a local unauthenticated forwarder — most clash / v2ray clients can listen on 127.0.0.1:7890 and handle upstream auth themselves. Then leave local_proxy_username / _password unset; only local_proxy_server: http://127.0.0.1:7890 reaches Chrome.
  • Use the browser-use agent — credentials go directly to Playwright via in-process ProxySettings(...) and never appear in the Chrome command line.

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Verifying the Proxy Is Active

Run a single task that needs the tunnel and inspect runtime.log: 
bubench run --agent skyvern --benchmark LexBench-Browser --mode by_id --id 89
If local_proxy_server is set, you should see Skyvern log Connected to proxy http://... and the navigation succeed. If you see net::ERR_CONNECTION_RESET or ERR_CONNECTION_TIMED_OUT on a site you can otherwise reach in your daily browser, the proxy is not wired — double-check the config block and that your tunnel client is actually listening on the configured port.