Run with Browser AI · Chapter 04
Run Chapter 04: Instrument the Application
Send valid and malformed application events across the page boundary and inspect exactly what the debugger can know.
← Read From Prompt Demo to AI Debugger
Execution
Not inspected
Observed state machine
What “built-in” means in this browser
No capability call has been made in this page yet.
- 01Not inspected
- 02Unsupported
- 03Unavailable
- 04Downloadable
- 05Downloading
- 06Available
- 07Session ready
- 08Running
- 09Completed
- 10Failed
Derived from events
Observatory measurements
Missing evidence stays missing. The dashboard never estimates an absent measurement.
Application instrumentation
Cross the boundary without erasing it
The page can validate what it sends. Extension receipt is confirmed only in the attached DevTools panel.
- 01Application SDKBuild a sanitized envelope
- 02Same-origin bridgeValidate schema and size
- 03Extension transportRoute by inspected tab
- 04DevTools panelConfirm receipt and correlate
To test end to end, load the Observatory extension, attach DevTools to this tab and enable instrumentation for this origin.
Shared lifecycle · distinct contracts
Browser AI capability switchboard
No interface has been inspected. Each check will use that interface's declared creation options.
| Interface | Global | Exposed | Availability | Options |
|---|
Canonical fixture · live task API
Summarization contract
Exposed Not inspected
Availability —
Session None
Load the canonical fixture, then inspect the current browser.
Generated artifact
No summary yet.
Contract evaluation
- No evaluation yet.
Ranked evidence · explicit routing policy
Language routing laboratory
Choose a fixture, then inspect Language Detector.
Ranked detector evidence
| Rank | Language | Confidence | Use |
|---|---|---|---|
| No ranked candidates yet. | |||
Translated artifact
No translation yet.
Translation evaluation
- No translation evaluation yet.
Resource state · measured lineage
Session lineage laboratory
Prompt API Not inspected
Availability —
Inspect the current browser before creating a session.
Original session
Not created- ID
- —
- Parent
- None
- Usage
- —
- Quota
- —
- Remaining
- —
- Clone / destroy
- —
No output yet.
Cloned session
Not created- ID
- —
- Parent
- —
- Usage
- —
- Quota
- —
- Remaining
- —
- Clone / destroy
- —
No output yet.
Shared-history acknowledgement
No shared-history run yet.
Lifecycle invariants
- No invariants evaluated yet.
Chapter experiment
From Prompt Demo to AI Debugger
Loading the chapter experiment…
No model output yet.
Inspect the context supplied by this chapter
What this experience knows
This experience is grounded in Chapter 04 and its explicit application-to-debugger contract.
Four planes
- the application plane performs browser-AI work and emits sanitized semantic events;
- the transport plane validates and moves envelopes across the extension boundary;
- the observability plane stores, correlates, filters and displays events;
- the control plane manages consent, capture mode, retention and destructive actions.
Trust boundary
A page-originated event is application-supplied evidence. It is not browser-attested merely because an extension accepted it. The source origin, SDK version, correlation identifiers and capture mode remain part of the envelope.
Default capture
Metrics-only mode records sizes, timings, state and outcomes without retaining prompt or response bodies. Content capture requires a separate, explicit decision.
End-to-end limit
This page can prove that it created an envelope and that the local validator accepted or rejected it. It cannot prove that an installed extension received the event. That receipt must be observed in the DevTools panel attached to the same tab.
This experience exercises the contract that turns an extension-owned prompt console into an application-aware debugger. Emit a metrics-only application event through window.postMessage, watch the local contract validator accept it, and try a malformed envelope to see it rejected.
When the Browser AI Observatory extension is loaded and instrumentation is enabled for this origin, the same valid event can continue through the installed bridge into the DevTools panel. The page deliberately cannot claim that the extension received it; confirmation belongs in DevTools.