Runtime overview
Asymptote supports browser chat on Claude.ai and ChatGPT through an optional Chrome MV3 extension that relays conversation telemetry into the same local pipeline as agent activity. The extension is in beta. It is not published on the Chrome Web Store and installs unpacked. It also reads the chat streams of two sites whose APIs are private and undocumented, so a change on either site can interrupt capture until the adapter is updated. Browser chat resolves to two harness names,claude_web and chatgpt_web, so browser activity is attributed separately from CLI agents in the runtime log and the dashboard.
Prerequisites
Before enabling browser chat telemetry, make sure:- The Beacon endpoint is installed and running. The extension posts to the local collector on
http://127.0.0.1:4318/v1/logs, which a default endpoint install already listens on, so no collector configuration is needed. - Chrome, or another Chromium browser that can load an unpacked MV3 extension. Firefox and Safari are not supported.
- Node 22 or newer, if you are building from source rather than using a release archive.
- You have reviewed what the extension retains. It captures full prompt and response text by default.
- The people whose browsers it runs in know it is there, since it reads their Claude.ai and ChatGPT conversations.
Collection path
A content script running in the page’s main world tees the streamed chat response, a per-site adapter parses it into a normalized turn, and the extension’s service worker posts OTLP GenAI logs to the local collector. Thebeaconjson exporter converts those into endpoint events and writes them to the runtime JSONL log, alongside every other source.
The extension never writes files and never contacts a remote endpoint. Delivery is queued in local extension storage and retried with backoff, so a turn survives the service worker being suspended mid-stream.
Events collected this way carry harness.collection_method of otlp.
Discovery and status
Asymptote treats the browser extension as a user-installed source. It is not configured bybeacon endpoint install, has no hook or plugin file on disk, and does not appear in beacon endpoint status, which reports on the endpoint service rather than on browser extensions.
Its presence is therefore observed rather than declared: the evidence that it is working is claude_web or chatgpt_web events arriving in the runtime log. See Confirm it is working.
Install or configuration support
The browser extension is in beta and is not published on the Chrome Web Store. It installs unpacked through Chrome’s developer mode, so Chrome will not auto-update it: to move to a new version, download it again and reload. The published archive is unsigned, and its
.sha256 is the only integrity check it has.Build it
No prebuilt archive is published yet, so building from source is currently the only way to get the extension. It needs Node 22 or newer and takes a few seconds:browser-extension/dist. Note the full path, because Chrome asks for it in the next step:
From a release archive
Once anext-v* release is published, you will be able to skip the build and download agent-beacon-browser-extension-<version>-chrome.zip with its .sha256 from the releases page, then verify and unzip it:
dist.
Load it in Chrome
- Open
chrome://extensions. - Turn on Developer mode, top right.
- Choose Load unpacked, then select the
distfolder you built (or the unzipped release folder). - Confirm “Agent Beacon — Browser Collector” now appears in the list and is enabled.
- Click the extension’s toolbar icon to check its status and, if you want, change the retention mode before capturing anything.
Configuration
The extension is configured in its own UI, not bybeacon. There is no CLI command and no config file on disk. Settings are split across two surfaces:
Review the retention mode in the popup before capturing anything on a machine where the same browser profile is used for personal conversations. The default retains full chat text.
Confirm it is working
Send one message on claude.ai or chatgpt.com, then look for the event:/var/log/beacon-agent/runtime.jsonl instead, and reading it needs sudo.
Or browse them in the local dashboard:
- The extension’s toolbar popup shows the queue depth and active streams. A growing queue means it captured the turn but cannot deliver it, which points at the collector rather than the adapter.
beacon endpoint statusconfirms the collector is running and listening on4318.- The service worker console, reachable from
chrome://extensionsby clicking “service worker” under the extension, shows delivery errors. - A hard reload of the chat tab. The interceptor installs at document start, so a tab opened before the extension was loaded is not instrumented until it reloads.
- Capture may be off, or off for that site. Check the popup and the options page.
chrome://extensions.
Retained content
Retention defaults tofull. Browser chat telemetry has little investigative value without content, so the default keeps it, and the tradeoff is documented rather than defaulted away.
Retention is enforced in the browser before anything is sent, so under
metadata the text never leaves the page. Endpoint-side redaction, sanitization, truncation, and event-size limits apply to whatever is sent.
Change the mode in the extension’s popup before enabling it on a machine where the same browser profile is used for personal conversations.

