.. _overview:


Overview
============
`Arch <https://github.com/katanemo/arch>`_ is a smart edge and AI gateway for AI-native apps - one that is natively designed to handle and process prompts, not just network traffic.

Built by contributors to the widely adopted `Envoy Proxy <https://www.envoyproxy.io/>`_, Arch handles the *pesky low-level work* in building agentic apps — like applying guardrails, clarifying vague user input, routing prompts to the right agent, and unifying access to any LLM. It’s a language and framework friendly infrastructure layer designed to help you build and ship agentic apps faster.


In this documentation, you will learn how to quickly set up Arch to trigger API calls via prompts, apply prompt guardrails without writing any application-level logic,
simplify the interaction with upstream LLMs, and improve observability all while simplifying your application development process.

.. figure:: /_static/img/arch_network_diagram_high_level.png
   :width: 100%
   :align: center

   High-level network flow of where Arch Gateway sits in your agentic stack. Designed for both ingress and egress prompt traffic.


Get Started
-----------

This section introduces you to Arch and helps you get set up quickly:

.. grid:: 3

    .. grid-item-card:: :octicon:`apps` Overview
        :link: overview.html

        Overview of Arch and Doc navigation

    .. grid-item-card:: :octicon:`book` Intro to Arch
        :link: intro_to_arch.html

        Explore Arch's features and developer workflow

    .. grid-item-card:: :octicon:`rocket` Quickstart
        :link: quickstart.html

        Learn how to quickly set up and integrate


Concepts
--------

Deep dive into essential ideas and mechanisms behind Arch:

.. grid:: 3

    .. grid-item-card:: :octicon:`package` Tech Overview
        :link: ../concepts/tech_overview/tech_overview.html

        Learn about the technology stack

    .. grid-item-card:: :octicon:`webhook` LLM Provider
        :link: ../concepts/llm_provider.html

        Explore Arch’s LLM integration options

    .. grid-item-card:: :octicon:`workflow` Prompt Target
        :link: ../concepts/prompt_target.html

        Understand how Arch handles prompts


Guides
------
Step-by-step tutorials for practical Arch use cases and scenarios:

.. grid:: 3

    .. grid-item-card:: :octicon:`shield-check` Prompt Guard
        :link: ../guides/prompt_guard.html

        Instructions on securing and validating prompts

    .. grid-item-card:: :octicon:`code-square` Function Calling
        :link: ../guides/function_calling.html

        A guide to effective function calling

    .. grid-item-card:: :octicon:`issue-opened` Observability
        :link: ../guides/observability/observability.html

        Learn to monitor and troubleshoot Arch


Build with Arch
---------------

For developers extending and customizing Arch for specialized needs:

.. grid:: 2

    .. grid-item-card:: :octicon:`dependabot` Agentic Workflow
        :link: ../build_with_arch/agent.html

        Discover how to create and manage custom agents within Arch

    .. grid-item-card:: :octicon:`stack` RAG Application
        :link: ../build_with_arch/rag.html

        Integrate RAG for knowledge-driven responses