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

# Hub, links, and viewers

> Where canvases live, how they travel, and where they are consumed.

The Hub is the registry, storage layer, and event log for canvases. Links are scoped capabilities. Viewers render canvases for humans.

## Hub

The Hub owns:

* Canvas registry
* Version history
* Patch and event streams
* Permissioned links
* Forking
* API access

The Hub is infrastructure. It lets agent output survive beyond a chat thread, shell session, or agent VM.

## Links

A Knify link is more than a URL. It is a permissioned capability.

| Link type         | Permission           | Example use                                |
| ----------------- | -------------------- | ------------------------------------------ |
| Public view link  | View only            | Share a client report                      |
| Private view link | View with auth       | Internal dashboard                         |
| Live view link    | View and subscribe   | Agent run monitor                          |
| Fork link         | View and fork        | Template distribution                      |
| Agent update link | Patch/write only     | Agent can update a canvas but not admin it |
| Owner link        | Full control         | Creator/admin                              |
| Embed link        | Restricted rendering | Website or dashboard embed                 |
| API link          | Read exported data   | Downstream integration                     |

The safe model:

```text theme={null}
Canvas ID != permission
Link token = scoped capability
Hub enforces permissions
Canvas JSON contains no secrets
```

## Viewers

Viewers render the same canvas contract across surfaces:

* Web viewer
* iPad/mobile viewer
* Embedded viewer
* Custom branded viewer

Viewers can change without changing the agent runtime. Agents can change without replacing the UI, links, dashboards, reports, or API consumers.