extension_assert

Run a test stage against a live dev session: state expectations and read one verdict for each, instead of reading a blob and hand-rolling the judgement.

Quick start

Check that the worker booted, the popup rendered and the console is clean

Asked whether the extension works, the agent states expectations and reads one verdict each.

Asked whether the extension works, the agent states expectations and reads one verdict each.

How the agent uses it

Every expectation comes back pass, fail or inconclusive, where inconclusive means this platform cannot cover the question today and the verdict says what would settle it. An inconclusive check is never a pass. Start the session with extension_dev; use extension_inspect or extension_logs when you want the raw reading instead of a verdict.

Page text in the answer

Part of this tool's answer is text a web page or the extension wrote. The server fences it between <untrusted-data-ID> and </untrusted-data-ID> with a fresh random ID per call, named in untrusted.boundary. A fence is a signal to the model, not a gate: pair it with --no-ship when the agent reads pages you do not trust. See Server flags and telemetry.

Reference

Group	local, on by default
Tier	Test
Needs	a live dev or start session
Read only	no
Destructive	no
Idempotent	yes
Reaches the open web	no

Inputs

Input	Type	Required	Default	What it does
projectPath	string	yes		Extension project root (needs a live dev session)
expect	array of object	yes		One object per expectation, each { assert: <check id>, ...args }. background-worker-booted: no args. surface-rendered: surface (popup, options, sidebar, newtab, history, bookmarks), optional selector and minNodes. content-script-injected: url. storage-key-present: key, optional area (default local), equals, context. console-errors-empty: optional context (array), since (seq cursor), ignore (substrings).
browser	string	no		Session browser; defaults to this project's live session
timeout	number	no		Command timeout in ms. When omitted, the default depends on the route: 30000 through the dev session's control channel, 10000 over the Firefox debugger protocol, and 15000 per command over the Chromium debug port.

When it fails

• The call is refused because no session is live. Start one with extension_dev or extension_start and call again.

Next

• MCP server: install, the two groups and the session gates
• Install in your client