[sonichi]

Summary

Companion to PR #719 (merged as 429de3d). #719 fixed the core-agent / CLAUDE.md path so mcp__claude-in-chrome__navigate reuses same-origin tabs. This PR fixes the voice-agent path: open_url (the inline tool Gemini Live calls for "open X" / "go to that link") previously always spawned a new Chrome tab.

Change

src/browser-tools.ts:openUrlTool:

• Queries active tab URL via osascript before opening.
• Parses both URLs to origins (scheme + host + port, matching PR docs(claude-md): default browser automation to reuse the active tab #719's terminology).
• Reuses active tab if origins match; spawns new tab if cross-origin.
• Any failure falls back to new-tab behavior — callers never silently lose the open.
• Tool description updated so Gemini's prompt sees the new behavior.

Why now

Same root cause as the CLAUDE.md fix (PR #719) but on a different surface. Together they cover both navigation paths into Chrome:

Path	Tool	Fix
Core agent (Claude Code)	mcp__claude-in-chrome__navigate	PR #719 (CLAUDE.md guidance)
Voice agent (Gemini Live)	open_url inline tool	This PR (in-tool behavior change)

Per Chi: "for voice what's the solution" (2026-05-15 09:31 PT).

Test plan

• Voice says "open github.com" → new tab.
• With github.com active, voice says "open github.com/sonichi/sutando" → same tab reused, tab count unchanged.
• Voice says "open example.com" with github active → new tab (cross-origin).
• CI: tsc + tests (clean install) — should pass; only browser-tools.ts changed.

🤖 Generated with Claude Code

[sonichi]

LGTM (cannot --approve own PR).

Logic trace (src/browser-tools.ts:openUrlTool):

• Target URL parsed via new URL(url).origin with try/catch → falls through to new-tab on bad input (about:blank, chrome:// schemes) ✓
• Active tab URL queried with 3s timeout; if same-origin, AppleScript set URL of active tab reuses it ✓
• Any failure on either osascript call falls through to new-tab — caller never silently loses the open ✓
• Logging + return-status distinguish reused vs opened paths ✓

Security: safeUrl escaping unchanged — still backslash → quote → double-quote sequence for the shell-+-AppleScript double envelope. The new osascript read takes no user input. No new injection vector.

Tool description: description grew from 65 → ~280 chars. That's longer than peers but justified — Gemini's tool-selection reads this; baking the new behavior into the description avoids needing a separate Gemini system-prompt update. Good call.

Edge cases verified by inspection:

• about:blank / chrome://settings/ → unparseable origin → new-tab fall-through ✓
• No front window → read errors → new-tab fall-through ✓
• Origin mismatch (cross-origin nav) → new-tab ✓

CI green, mergeable. Companion to merged PR #719 — both navigation paths into Chrome now respect same-origin tab reuse. Safe to land.