> **Building with AI coding agents?** If you're using an AI coding agent, install the official Scalekit plugin. It gives your agent full awareness of the Scalekit API — reducing hallucinations and enabling faster, more accurate code generation.
>
> - **Claude Code**: `/plugin marketplace add scalekit-inc/claude-code-authstack` then `/plugin install <auth-type>@scalekit-auth-stack`
> - **GitHub Copilot CLI**: `copilot plugin marketplace add scalekit-inc/github-copilot-authstack` then `copilot plugin install <auth-type>@scalekit-auth-stack`
> - **Codex**: run the bash installer, restart, then open Plugin Directory and enable `<auth-type>`
> - **Skills CLI** (Windsurf, Cline, 40+ agents): `npx skills add scalekit-inc/skills --list` then `--skill <skill-name>`
>
> `<auth-type>` / `<skill-name>`: `agent-auth`, `full-stack-auth`, `mcp-auth`, `modular-sso`, `modular-scim` — [Full setup guide](https://docs.scalekit.com/dev-kit/build-with-ai/)

---

# Bring your own provider

Bring your own provider lets you add custom providers to Agent Auth when the API you need is not available as a built-in provider.

Use bring your own provider to support unsupported SaaS APIs, partner systems, and internal APIs while keeping authentication, authorization, and secure API access in Scalekit.

Once the provider is created, you use the same Agent Auth flow as other providers: create a connection, create or fetch a connected account, authorize the user, and call the upstream API through Tool Proxy.

Custom providers appear alongside built-in providers when you create a connection in Scalekit:

![Custom provider shown alongside built-in providers in the provider selection view](@/assets/docs/agent-auth/bring-your-own-provider/custom-provider-in-catalog.png)

## Why use bring your own provider

Bring your own provider lets you:

- Extend Agent Auth beyond the built-in provider catalog without inventing a separate auth stack
- Bring unsupported SaaS APIs, partner systems, and internal APIs into the same secure access model
- Reuse connections, connected accounts, and user authorization instead of building one-off auth plumbing
- Keep credential handling, authorization, and governed API access centralized in Scalekit
- Move from provider definition to live upstream API calls through Tool Proxy using the same runtime model as other integrations
**Note:** Bring your own provider is for proxy-only connectors.

## How bring your own provider works

Bring your own provider uses the same Agent Auth model as built-in providers:

1. Create a provider definition
2. Create a connection in Scalekit Dashboard
3. Create a connected account and authorize the user
4. Use Tool Proxy to call the upstream API

Creating the provider defines how Scalekit should authenticate to the upstream API. After that, connections, connected accounts, user authorization, and Tool Proxy work the same way as they do for built-in providers.

---

## More Scalekit documentation

| Resource | What it contains | When to use it |
|----------|-----------------|----------------|
| [/llms.txt](/llms.txt) | Structured index with routing hints per product area | Start here — find which documentation set covers your topic before loading full content |
| [/llms-full.txt](/llms-full.txt) | Complete documentation for all Scalekit products in one file | Use when you need exhaustive context across multiple products or when the topic spans several areas |
| [sitemap-0.xml](https://docs.scalekit.com/sitemap-0.xml) | Full URL list of every documentation page | Use to discover specific page URLs you can fetch for targeted, page-level answers |