# SDK

> @fastyoke/sdk — build extensions, page designer blocks, and host integrations.

# SDK

`@fastyoke/sdk` is the public TypeScript SDK on npm (mirrored as
`versacomp/fastyoke-sdk` for the GitHub Package Registry). Use it to
build:

- **Extensions** — React bundles that mount inside the admin shell
  and receive a scoped JWT with the current user's context.
- **Page designer blocks** — custom block types that show up in the
  Page Designer palette alongside the built-ins.
- **Host integrations** — Node or browser callers that hit the
  tenant-scoped API with a proper session token.

## Stability

The SDK follows the deployed platform version. Breaking changes are
documented with a `
> **Note**
>
> ` block on the
> affected API, plus an entry in the changelog. Most changes are
> additive.
>
> ## Module shape
>
> ```ts
import {
  FastYokeProvider,
  useFastYoke,
  useCurrentUser,
  ApiError,
  // ...plus block and extension registration helpers
} from '@fastyoke/sdk';
```
>
> The SDK's types ship as TypeScript declarations in the same
> package — no `@types/fastyoke-sdk` needed.
>
> ## Two environments
>
> - **Inside the admin shell** — extensions receive the platform's
>   React + SDK instances via the import map. State (React context,
>   including `FastYokeContext`) crosses the boundary cleanly.
> - **Outside the shell** — Node scripts or your own frontend import
>   the SDK normally. You're responsible for minting a user JWT or
>   using a static API key (see [Authentication](/docs/auth)).
>
> 
>   <code>vite serve</code> routes the host's React through the dep
>   optimizer while extensions still resolve via the import map —
>   that's two React instances, which breaks hooks. Always test
>   extensions against <code>npm run build && npm run preview</code>,
>   or deploy to Fly.