[Bug]: Antigravity installation, Google sign-in, and usage limits fail behind HTTP proxy #33032

Before submitting#

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area#

apps/server

Steps to reproduce#

Run T3 Code on Windows with a Fedora WSL2 backend.

Configure HTTP_PROXY and HTTPS_PROXY to use a local HTTP proxy.

Attempt to install Antigravity or fetch usage limits without NODE_USE_ENV_PROXY=1. Both fail due to connection timeouts, while curl works.

Enable NODE_USE_ENV_PROXY=1 and restart the backend. Downloads and usage-limit queries now work.

Retry Antigravity installation or Google sign-in. Browser suppression verification fails because Node.js emits an UNDICI-EHPA warning.

Set NODE_NO_WARNINGS=1. Installation and Google sign-in succeed.

Expected behavior#

Antigravity installation, Google sign-in, and usage-limit queries should work with an HTTP proxy without requiring global Node.js warning suppression.

Actual behavior#

Without NODE_USE_ENV_PROXY=1, Google requests fail with connection timeouts.

With it enabled, Node.js emits an experimental Undici warning to stderr. T3 Code's browser helper rejects the additional output, causing installation validation and Google sign-in to fail.

The helper itself exits successfully with code 0 and produces the expected authentication marker.

Impact#

Major degradation or frequent failure

Version or commit#

T3 Code 0.1.7

Environment#

Windows + FedoraLinux-43 (WSL2, x86_64), Node.js v22.22.0, Antigravity ACP, HTTP proxy at 127.0.0.1:7897

Logs or stack traces#

ConnectTimeoutError: Connect Timeout Error (attempted address: dl.google.com:443, timeout: 10000ms)

AntigravityInstallationError: The downloaded Antigravity runtime could not start in this environment.
AcpTransportError: ACP transport operation failed: Antigravity browser suppression could not be verified.

Exit: 0
Stdout: b''
Stderr: expected auth URL marker followed by:
[UNDICI-EHPA] Warning: EnvHttpProxyAgent is experimental
Exact match: False

Confirmed findings#

1. Without NODE_USE_ENV_PROXY=1:

• Antigravity download fails with ConnectTimeoutError.
• Usage-limit queries fail.
• The same Google download URL works through curl.

2. With NODE_USE_ENV_PROXY=1:

• Downloads and usage-limit queries work.
• Antigravity browser suppression verification fails.

3. Browser helper reproduction:

• Exit code: 0
• stdout: empty
• stderr: expected authentication marker followed by: [UNDICI-EHPA] Warning: EnvHttpProxyAgent is experimental
• Exact stderr match: False

4. With NODE_NO_WARNINGS=1 additionally enabled:

• Antigravity installation succeeds.
• Google sign-in succeeds.

The browser helper's actual behavior matches the expected output except for the additional Node.js warning. This strongly suggests that strict stderr comparison is causing the preflight failure.

The Google sign-in behavior was verified experimentally, but a separate authentication failure stack trace was not captured.

Screenshots, recordings, or supporting files#

No response

Workaround#

Setting both environment variables fixes the observed issues:

• NODE_USE_ENV_PROXY=1 — enables proxy support for downloads and usage-limit queries.
• NODE_NO_WARNINGS=1 — prevents Node.js warnings from breaking installation verification and Google sign-in.

However, NODE_NO_WARNINGS=1 suppresses all Node.js warnings.

A better fix would be to isolate the browser-helper environment from unnecessary proxy settings, while keeping proxy support for network requests.