> ## 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.

# Composability

> Why Meerkat is both a composable library and a practical product layer.

Composability is the core idea that explains almost everything else in Meerkat.

Meerkat is:

* a **library-first runtime**
* with a **practical product layer**
* exposed through **multiple peer surfaces**

That means the same underlying system can be used as:

* a Rust crate embedded in your app
* a Python or TypeScript SDK backend
* a CLI for hands-on work
* a REST / JSON-RPC / MCP integration surface
* a multi-agent runtime

## Why this matters

Because Meerkat is composable:

* the surfaces are not separate products with separate semantics
* examples should usually treat the major surfaces as peers
* concepts such as realms, sessions, tools, and mobs should make sense across surfaces
* advanced builder/developer docs can still be part of the public docs set, because the “developer” and “operator” roles often overlap

## The Practical Consequence

Composability means the same decisions show up across surfaces:

* model and provider choice is resolved through one model registry
* tools, skills, hooks, and memory are composed into one agent build path
* persistent state is scoped by realm rather than by one CLI invocation
* mobs coordinate multiple sessions without inventing a second agent runtime
* release and deployment choices affect real users because SDKs and binaries
  share the same runtime surfaces

## See also

* [Concepts overview](/concepts/overview)
* [Tools](/concepts/tools)
* [Mobs](/concepts/mobs)
* [Architecture](/reference/architecture)