Description

The web_fetch tool's custom http.Transport was missing the Proxy field, causing it to silently ignore HTTP_PROXY/HTTPS_PROXY/NO_PROXY environment variables. This is a one-line fix.

Type of change

• Bug fix (non-breaking change which fixes an issue)

AI-Generated Code Disclosure

• Mostly Human (Human draft, AI assisted)

Related Issue

Closes #413

Root Cause

When constructing an http.Transport{} manually, the Proxy field defaults to nil (no proxy). This is different from http.DefaultTransport, which sets Proxy: http.ProxyFromEnvironment.

The search providers (Brave, DuckDuckGo, Perplexity) use &http.Client{Timeout: ...} with a nil Transport, so they correctly inherit http.DefaultTransport and respect proxy env vars. But WebFetchTool.Execute() constructs a custom transport (for connection pooling and TLS tuning) that was missing the proxy field.

// Before — no proxy support:
Transport: &http.Transport{
    MaxIdleConns:        10,
    IdleConnTimeout:     30 * time.Second,
    DisableCompression:  false,
    TLSHandshakeTimeout: 15 * time.Second,
},

// After — respects HTTP_PROXY/HTTPS_PROXY:
Transport: &http.Transport{
    Proxy:               http.ProxyFromEnvironment,
    MaxIdleConns:        10,
    IdleConnTimeout:     30 * time.Second,
    DisableCompression:  false,
    TLSHandshakeTimeout: 15 * time.Second,
},

Note on PR #422

PR #422 attempts to fix this same issue but targets the wrong code path — it adds Transport: http.DefaultTransport to the Brave search provider, which is a no-op since nil Transport already uses DefaultTransport. See my review on #422 for details.

Test Environment

• Hardware: MacBook Air M4
• OS: macOS 15.4
• Go version: 1.25.7

Evidence

All existing web tool tests pass:

--- PASS: TestWebTool_WebFetch_Success
--- PASS: TestWebTool_WebFetch_JSON
--- PASS: TestWebTool_WebFetch_HTMLExtraction
--- PASS: TestWebTool_WebFetch_Truncation
(10 tests total, all passing)

Self-review checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• My changes generate no new warnings
• New and existing unit tests pass locally with my changes