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

# Auth And Bindings

> How Meerkat separates provider selection from credential resolution and binding identity.

Meerkat separates **what model/backend you want** from **which credentials or account should be used**.

The core pieces are:

* realms
* auth profiles
* backend profiles
* bindings
* `auth_binding`

This model matters because the same app/session/mob can:

* switch providers without changing its overall structure
* run different mob members under different tenants/accounts
* use env-var fallback for fast paths and explicit bindings for controlled paths

## Mental model

```text theme={null}
realm
  -> backend profiles
  -> auth profiles
  -> bindings

session / turn / mob member
  -> auth_binding
  -> provider runtime resolution
```

## What this concept owns

* binding identity
* credential resolution path
* per-session / per-turn / per-member provider identity choice

## What it does not own

* the general model catalog (`Providers`)
* session lifecycle (`Sessions`)
* config write/CAS mechanics (`Configuration`)

## See also

* [Realms](/concepts/realms)
* [Providers](/concepts/providers)
* [Auth guide](/guides/auth)