> ## Documentation Index
> Fetch the complete documentation index at: https://docs.karta.sh/llms.txt
> Use this file to discover all available pages before exploring further.
# Chat widget
> Drop a hosted, themeable agent chat widget onto any site with one async script tag.
The Karta chat widget is a prebuilt launcher + chat panel you embed with a
single async `
```
That is the whole drop-in. The tag is `async`, so it never blocks your page; the
loader reads its own `data-*` attributes, lazily fetches the UI on demand, and
mounts a launcher in the corner.
## Expected result
A chat launcher appears in the bottom-right corner. Clicking it opens the panel
and starts a session against your agent; messages stream back token by token.
The look and copy (accent color, greeting, suggested prompts) are pulled from
the agent's Embed-tab config at runtime - so you can restyle the widget without
touching this tag. The displayed identity is the named Karta's name when the
key or URL selects one, and the underlying agent's name otherwise. See
[Theming & config](/sdks/widget/theming).
## Hosted surfaces
If you want an agent-bound URL instead of the generic CDN loader, use one of the
surfaces served from the agent host:
| Surface | Path or snippet | Use |
| ------------------ | ----------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Hosted chat page | `https://agent.karta.sh/coffeeco/support-bot` | Share a full-page chat for the deployed agent. Dashboard share links can append `?key=pk_live_xxx`; a bare hosted page mints its browser-safe token from the agent origin. |
| Chromeless iframe | `https://agent.karta.sh/coffeeco/support-bot/embed` | Put the full chat panel inside your own frame or app shell. |
| Agent-bound loader | `` | Inject the same widget loader with the agent reference and runtime origin already baked in. |
Use the generic CDN loader when you want all configuration on your own page. Use
the agent-bound loader when the agent coordinate should come from the URL itself.
## Customize inline
You can override any theme field on the tag with `data-theme-*`:
```html theme={null}
```
See the full attribute list in [Theming & config](/sdks/widget/theming).
## Where to go next
Open the widget from your own button, identify the user, and react to
events with `karta(...)`.
Anonymous, soft, and verified (HMAC) identity - and which one to use.
Server-side recipe for signed-in users and step-up.
The Embed-tab fields, runtime config, and the consent option.
CSP directives, the origin allowlist, and the data path.