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

# Connections & Proxy

> Connected tools, model APIs, and the proxy that authenticates them.

A **connection** links a workspace agent to an external toolkit or provider — a SaaS integration, a data source, or a model vendor — so the agent can act through it with managed auth and billing.

## The proxy

The **proxy** is the single authenticated surface agents use to reach connected tools, model providers, and selected external data providers. It centralizes:

* Authentication (the `pak_` [API key](/concepts/workspace#api-keys)).
* Billing and credit preflight.
* Permission and access checks.
* Request attribution.
* Provider-specific request routing.

Because the proxy handles auth and billing uniformly, an agent uses one credential and one base URL rather than managing per-vendor secrets.

## What the proxy covers

* **Tools API** — search toolkits, authorize, inspect, and execute connected tools. See [Tools API](/proxy/tools-api).
* **App Connection API** — use source-agent connections from server-side App code. See [App Connection API](/proxy/app-connections).
* **Model APIs** — OpenAI-, Anthropic-, Gemini-, and other-compatible model routes. See [Model APIs](/proxy/model-apis).
* **Provider APIs** — non-model data providers. See [Provider APIs](/proxy/provider-apis).

Start at the [Proxy Overview](/proxy/overview).