> ## Documentation Index
> Fetch the complete documentation index at: https://docs.celerflow.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Browser extension

> Capture paywalled PDFs in your own browser session so BioMed workflows can continue.

The CelerFlow browser extension powers **browser handoff** — the mechanism that lets a [BioMed](https://docs.celerflow.ai/concepts/biomed.md) workflow obtain a PDF that sits behind a paywall or institutional login, without CelerFlow ever bypassing the publisher's access controls.

## Why it exists

When a BioMed run reaches a paper whose PDF isn't openly available, the `institutional_access_agent` creates a handoff session and pauses the run. Rather than scraping around the paywall, CelerFlow asks *you* to fetch the file in a browser where you're already authenticated — through your library proxy or institutional login. The capture happens on your authority, in your session.

## How a handoff works

**1. A run pauses**

A BioMed workflow hits a paywalled paper and opens a handoff session. The workflow waits.

**2. You capture the PDF**

With the extension installed, open the paper in your authenticated browser. The extension captures the PDF and sends it back to the workflow.

**3. The run resumes**

CelerFlow attaches the captured PDF and the workflow continues automatically — on to triage, citation resolution, and Zotero export.

## Install and configure

Open the **Browser extension** settings page (`/{slug}/settings/extension`) for the install link and setup steps. Once installed, the extension links to your workspace so handoff sessions route to the right account.

## Availability

The browser handoff extension is available on **all plans**, including Free. The BioMed agents that create handoff sessions, however, require a paid plan — see [Billing](https://docs.celerflow.ai/platform/billing.md).

## See also

* [BioMed research pack](https://docs.celerflow.ai/concepts/biomed.md) — where browser handoff fits in the pipeline.
* [Approvals](https://docs.celerflow.ai/concepts/approvals.md) — handoff is the one run-time human-in-the-loop pause.


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