privacy

Gasoline v5.1.0: Single-Tab Tracking Isolation

Jan 28, 2026

Brenn Hill

Gasoline v5.1.0 is a security-focused release that fixes a critical privacy vulnerability in how the extension captures browser telemetry. If you’re running any previous version, upgrade immediately.

The Problem: All Tabs Were Captured

Prior to v5.1.0, the extension captured console logs, network requests, and other telemetry from every open browser tab — regardless of whether tracking was enabled for that tab. If you had 40 tabs open and clicked “Track This Page” on one of them, data from all 40 tabs was forwarded to the MCP server.

This was a privacy vulnerability. Tabs containing banking sites, personal email, or other sensitive sessions would leak telemetry into the AI assistant’s context.

The Fix: Single-Tab Tracking Isolation

v5.1.0 introduces tab-scoped filtering in the content script. The extension now:

Only captures from the explicitly tracked tab. All other tabs are completely isolated.
Attaches a tabId to every forwarded message for data attribution.
Blocks Chrome internal pages (chrome://, about://, devtools://) from being tracked.
Clears tracking state on browser restart — no stale tab references.

The button has been renamed from “Track This Page” to “Track This Tab” to reflect the actual behavior.

”No Tracking” Mode

When no tab is tracked, the MCP server now prepends a warning to all observe() responses:

WARNING: No tab is being tracked. Data capture is disabled. Ask the user to click ‘Track This Tab’ in the Gasoline extension popup.

This prevents the AI assistant from silently operating on stale or missing data.

Network Schema Improvements

API responses from network_waterfall and network_bodies now include:

Unit suffixes: durationMs, transferSizeBytes instead of ambiguous duration, size
compressionRatio: Computed field showing transfer efficiency
capturedAt timestamps on all entries
limitations array explaining what the data can and can’t tell you

These changes help LLMs interpret network data without guessing units.

PyPI Distribution

Gasoline is now available on PyPI alongside NPM:

pip install gasoline-mcp
gasoline-mcp

Same binary, same behavior. Platform-specific wheels for macOS (arm64, x64), Linux (arm64, x64), and Windows (x64).

Known Issues

Five issues are deferred to v5.2. See KNOWN-ISSUES.md for details:

query_dom not yet implemented
Accessibility audit runtime error
network_bodies returns no data in some cases
Extension timeouts after several operations
observe() responses missing tabId metadata

Upgrade

npx gasoline-mcp@5.1.0

Or update your .mcp.json:

{
  "mcpServers": {
    "gasoline": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "gasoline-mcp@5.1.0", "--port", "7890", "--persist"]
    }
  }
}

Full Changelog

GitHub Release · CHANGELOG.md