X9 Browser Session

Browser session

Use this skill in OpenCode, Claude Code, and Codex. It owns shared route selection, the verified Edge adapter, runtime-specific extension and in-app surfaces, CDP fallbacks, task-tab isolation, and focus safety. Re-check installed tool instructions and live schemas when a named surface is absent.

chrome-devtools MCP allowlist

Targets in this list bypass the browser extension in every route that offers one. An entry matches the exact hostname and its subdomains; do not infer sibling or look-alike domains.

• avito.ru

Avito traffic discipline

Treat one account, browser profile, and public IP as one browsing lane for the whole parent task. Avito work is sequential even when the rest of the research is delegated:

• appoint one Avito operator; subagents may analyze captured data but must not browse avito.ru concurrently;
• keep only one Avito navigation, search, or listing load in flight. Prefer one task tab; extra tabs may hold queued pages, but interact with only one at a time;
• let the current page finish loading and inspect it before requesting the next page; shortlist from search results and reuse captured data instead of repeatedly reopening or refreshing listings;
• do not bulk-load listings, paginate rapidly, poll availability, or run retry loops;
• when Avito shows an IP or security-check interstitial that requires no user action, keep the same page, controller, and profile. Wait five seconds once without reloading, navigating, or initiating another request, then inspect the same page again. Continue serial browsing if the requested content is visible;
• if the same interstitial remains on the second inspection, or Avito returns a CAPTCHA requiring user action, 429, timeout, access-denied, or an error page, treat it as site throttling rather than a controller failure. Stop Avito requests across the parent task, preserve collected results, and return DEGRADED; do not switch controllers, profiles, agents, or IP addresses to continue;
• resume only when the user requests another check or ordinary access is already visibly restored. Perform that check serially through the same browser profile.

Choose the surface

1. Prefer a purpose-built connector, API, or CLI when it can perform the semantic operation. An explicit request to open, inspect, or operate a browser UI overrides this preference.
2. When the target hostname matches the chrome-devtools MCP allowlist, use the runtime's MCP route: OpenCode uses the live chrome-devtools target in its current tool catalog without inferring a profile; Claude Code and Codex use MCP against the verified Edge profile. This route overrides the runtime default and an explicit in-app selection. If MCP cannot attach or complete the operation, continue directly to the agent-edge fallback under the shared unattended-Edge condition.
3. In Claude Code or Codex, use the runtime's in-app browser immediately when the user explicitly requests it. That explicit choice is sticky: do not substitute Edge or another browser after an authentication or connection failure unless the user approves the switch.
4. In Claude Code or Codex, use the runtime's in-app browser for local web development and previews unless the user explicitly requests Edge:
   • Codex: its in-app browser;
   • Claude Code: its Browser pane.
5. For every other browser-control task, use the runtime-specific default:
   • OpenCode: the live chrome-devtools MCP exposed in the current tool catalog;
   • Codex: its browser extension in the verified Edge profile;
   • Claude Code: chrome-devtools MCP against that Edge profile. Do not use the Claude browser extension unless the user explicitly requests it.
6. In Codex, if the extension is unavailable, disconnected, or lacks a required DevTools capability, retry its documented recovery once and then use chrome-devtools MCP against the same Edge profile.
7. If MCP cannot attach or cannot perform the required operation, use agent-edge, which connects agent-browser to the same Edge profile. Because the current agent-browser brings newly created and selected tabs to the foreground, use this fallback only when the user is not simultaneously working in Edge. If that condition is unknown and the fallback would require creating or switching tabs, ask one short question instead of taking over the window.
8. Once a controller works, keep it through ordinary stale-reference, redraw, and timeout errors. Do not alternate controllers on the same task tab.

Outside the allowlist route above, the in-app browser remains the isolated route in Claude Code and Codex for an explicit request and local web development. It has a separate profile and does not carry the user's Edge extensions. Use Edge when exact account state, region, cart, saved data, personalized content, ad blocking, or another installed extension matters.

Shared Edge safety

Treat the executable, profile, extensions, localhost CDP endpoint, launcher, and controllers as adapter parameters. On another machine, substitute and verify them instead of copying the Edge-specific values below.

• use the dedicated, continuously used automation profile rather than the browser's default profile;
• attach every controller to that same existing Edge profile rather than launching a clean browser;
• before authenticated or private work, verify that the CDP discovery endpoint returns success and belongs to the browser process using the expected automation profile; controller availability alone does not establish profile identity;
• create a task-owned background tab; never assume the user's active tab is the task tab;
• when the task depends on the existing authenticated profile, never pass isolatedContext or an equivalent new-context option; a task-owned tab provides isolation without discarding that profile's cookies and storage;
• with an extension, use its session-owned logical task tab and leave it inactive;
• with chrome-devtools, create the page with background: true, select it with bringToFront: false, and never invoke Page.bringToFront or Target.activateTarget;
• never control one tab through the extension and CDP at the same time;
• keep credentials, cookies, tokens, and local storage in the dedicated browser profile rather than copying them into prompts or repository files;
• assume the controller and model can receive inspected page contents and network data; avoid opening unrelated private surfaces, do not capture network headers unless the task requires them, and never echo secret header values into chat, logs, or files.

Do not run browser-wide HAR or broad network capture in the personal Edge profile. Use a clean standalone agent-browser session for that work.

Verified Edge adapter

• Profile: ~/Library/Application Support/Microsoft Edge Automation.
• Launcher: ~/Applications/Edge (Agent).app with remote-debugging port 9223.
• Codex primary outside the exceptions in Choose the surface: the ChatGPT browser extension installed in this Edge.
• Claude Code primary outside the local-development exception: chrome-devtools MCP.
• Codex MCP route: chrome-devtools MCP configured with --browserUrl http://127.0.0.1:9223.
• Last fallback: agent-edge, which wraps agent-browser --cdp 9223 against the same profile.
• Leave pre-existing tabs, windows, downloads, bookmarks, and settings untouched.
• Re-snapshot after navigation, filtering, modal changes, and redraws because element references become stale.
• If an Edge route cannot attach, confirm that Edge (Agent).app is running before declaring that controller unavailable.

Read before mutating. Posting, purchasing, sending, deleting, or changing account data still requires authority from the user's request.

OpenCode

• Use the live chrome-devtools MCP in the current tool catalog as the primary browser-control surface. Do not infer configuration paths, flags, or a separate in-app browser from another runtime.
• Create a task-owned page with background: true, select it with bringToFront: false, and keep one controller on that task page. Apply the shared private-surface safety and Avito traffic rules.
• If the MCP is absent, use agent-edge only under the shared unattended-Edge condition. A restart conclusion is permitted only when safe evidence shows that the MCP is configured but not visible in the live catalog; otherwise return DEGRADED or BLOCKED with the missing prerequisite.

Claude Code

• For local web development, previews, and an explicit request for the built-in browser, use the Claude Code Browser pane. Read its current tool instructions before acting; this exception remains primary for that scope.
• For other browser work, use the chrome-devtools MCP from ~/.claude.json with the shared focus-safe rules. Do not initialize or fall back to the Claude browser extension unless the user explicitly requests that extension.
• If MCP tools are absent after Edge is running, restart Claude Code once. Use agent-edge only under the shared unattended-Edge condition.

Codex

• For local web development, previews, and an explicit request for the in-app browser, read and follow browser:control-in-app-browser and select its distinct in-app binding immediately. This exception remains primary for that scope.
• Except for the allowlist route in Choose the surface, select the Edge extension directly for other browser work. Do not let getDefault() or getForUrl() silently choose the in-app browser. Read and follow the installed chrome:control-chrome skill; it owns the current setup and extension APIs.
• The Codex MCP route uses ~/.codex/config.toml and the shared focus-safe rules. Outside the earlier exceptions, enter it only after the Edge extension remains unavailable following its documented troubleshooting.
• If MCP tools are absent after Edge is running, restart Codex once. Use agent-edge only under the shared unattended-Edge condition.

Install an adapter

Read references/setup.md for the portable adapter contract and the verified Edge example. Never commit browser profile contents or credentials.

Failure behavior

For the Avito signals defined in Avito traffic discipline, follow that section's stop rule instead of entering the controller fallback chain.

Report cancelled or failed browser calls as failures. For an implicit/default browser selection, use the runtime-specific chain: Codex extension → MCP → agent-edge; OpenCode MCP → agent-edge; Claude Code MCP → agent-edge; use the allowlist route defined in Choose the surface instead of the Codex default. For an allowed explicit in-app choice, do not enter an Edge chain without approval. If an implicitly selected local-development browser is unavailable, use the runtime's Edge chain and report the fallback. Do not substitute remembered data or a public page when the task required the authenticated source. Return DEGRADED or BLOCKED with the failed route and missing prerequisite when the permitted chain is exhausted.

Done

Report the runtime, browser surface, controller, task-owned tab or page, requested result, and any checks that could not be completed. For mutating work, verify the resulting UI state or server response before claiming completion.

The onboarding declaration is the machine-readable onboarding contract.