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

# Adding lenses

> Browse the lens marketplace, try a lens, and keep it open on every session

A lens is a focused view of one session: the files it changed, what it cost, what a reviewer should
look at. Beacon Cloud ships built-in lenses, and anyone can publish more to the marketplace. Add a
lens once and it is available on every session you open.

## Built-in lenses

Every session already has these. Select **+** on a session's tab bar to open one.

| Lens | What it shows |
| - | - |
| **Activity** | Actions, commands, failures and findings |
| **Files Changed** | Created, edited and deleted files |
| **Token Usage** | Usage and cost signals by model |
| **Security Review** | Sensitive and consequential activity |
| **Approvals & Policy** | Operator and policy decisions |
| **Skills** | Skills loaded during the session |
| **MCP Calls** | Calls grouped by server and tool |

## Browse the marketplace

The marketplace at [beacon.sh/lenses](https://beacon.sh/lenses) lists every public lens. Each card
shows the lens's author, how many people installed it and its current version. You can browse
without signing in.

## Try a lens before adding it

Select a card to open the lens's page at `/lenses/<key>`. It shows the description, the author and
the current version, and a **Live preview** that runs the lens against a sample session, so you can
see what it does before it touches your own data.

## Add a lens

Select **Add lens** on the lens's page. You need to be signed in.

> [!WARNING]
>
> A lens written by someone else can read every session you open it on, including prompts, code
> and tool output. Beacon blocks lenses from sending anything out, but only add lenses from
> authors you trust.

Added lenses belong to your account, not to a session. To remove one, select **Remove lens** on the
same page, or **Remove** on the [Lenses](https://beacon.sh/dashboard/lenses) page in the dashboard.

## Lenses on the session page

On a session, select **+** to open the lens menu. Built-in lenses come first, then the lenses you
added under **Installed**. Each lens you open becomes a tab next to **Full session**; select **×**
to close it. Beacon remembers your open tabs in this browser.

The selected lens is kept in the URL as `?lens=<key>`, so you can share a link that opens straight
to it. The person you share it with sees the lens only if they have added it too; otherwise Beacon
asks them to add it from the marketplace.

## Related

> **[Creating lenses](/cloud/lenses/creating-lenses)**
>
> Build a lens with your coding agent or upload one.

> **[Managing lenses](/cloud/lenses/managing-lenses)**
>
> Release new versions and choose who can find a lens.


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