`. |
| `ReintersectTokenInvalidError` | The tagged error behind a rejected token, with a `reason`. |
| Types | `McpAuth`, `McpHandler`, `McpFetchHandler`, `McpRequestExtra`, `ReintersectAuthInfo`, `ReintersectCaller`, `ReintersectTokenVerifier`, `VerifyReintersectTokenOptions` |
To mount an MCP server on your app, call `.addMcp` on the app. See [MCP servers](/mcp/servers).
### `@reintersect/sdk/testing` and `@reintersect/sdk/effect/testing`
`createTestHost(app, options?)` on the Promise entry; `makeTestHost(app, options?)` and
`ReintersectTestHost` (a service with `ReintersectTestHost.layer(app, options?)`) on the Effect entry.
Both export `textOf`, `findNodes`, `buttonsOf`, `buttonOf`, `treeFor`, `checkTree`, `expectTree`,
`testViewer`, `TEST_SIGNING_SECRET`, `TREE_LIMITS` and the test error classes. See
[Testing](/testing).
### `@reintersect/sdk/effect` and `@reintersect/sdk/effect/app`
`/effect` exports the Effect member API client (`Reintersect`, `ReintersectClient`), the app client
`ReintersectAppClient.make(app, options)`, `renderPayload` and `ReintersectStream`.
`/effect/app` exports `createReintersectApp`, `defineBlock`, `defineAction`, `defineReference`,
`defineEvent`, `defineCommand`, `defineMessageAction`, `defineRoute`, `choice`, `secret`, `provide`, `manifestOf`,
`toNodeHandler`, the `ReintersectApp` namespace (`ReintersectApp.layer`) and the app error classes.
See the [Effect guide](/effect).
## JSX configuration
Blocks and documents use the automatic JSX transform with the SDK as the import source. Set it once
in `tsconfig.json`:
```json tsconfig.json theme={null}
{
"compilerOptions": {
"jsx": "react-jsx",
"jsxImportSource": "@reintersect/sdk",
"strict": true
}
}
```
Effect apps use the same setting, which already accepts components that return an `Effect`. You can
also set the import source per file:
```tsx theme={null}
/** @jsxImportSource @reintersect/sdk */
```
There are no intrinsic elements: `` is a type error, because blocks are built only from the
catalog. Components may return JSX, a `Promise` of JSX, or, on the Effect entry, an `Effect` of JSX.
## Schemas
Props, state, action args, action input, install config and environment values all take a schema.
On the non-Effect entry points, a schema must implement both
[Standard Schema V1](https://standardschema.dev) and Standard JSON Schema V1. Reintersect validates
values, and it also needs JSON Schema for forms, agent tools and the manifest.
| Library | Minimum version | Notes |
| - | - | - |
| Zod | 4.2 | The default in templates and these docs. |
| ArkType | 2.1.28 | Object schemas sort their keys. See [Order](/commands#order). |
| Valibot | 1.x | Wrap each schema with `toStandardJsonSchema()` from `@valibot/to-json-schema`. |
| Effect Schema | Effect 3.x | Only on `@reintersect/sdk/effect/app`. |
```ts theme={null}
import { toStandardJsonSchema } from "@valibot/to-json-schema";
import * as v from "valibot";
const props = toStandardJsonSchema(v.object({ title: v.string() }));
```
Passing an unsupported schema is a type error with one of these messages:
| Schema | Message |
| - | - |
| Effect Schema on a non-Effect entry | `Effect Schema values belong to the Effect entry: import from @reintersect/sdk/effect/app` |
| Valibot without the adapter | `Valibot schemas need JSON Schema support: wrap it with toStandardJsonSchema() from @valibot/to-json-schema` |
| A Standard Schema with no JSON Schema support | `This schema cannot produce JSON Schema (StandardJSONSchemaV1). Use zod >= 4.2, arktype >= 2.1.28, or valibot with toStandardJsonSchema()` |
| Anything else | `Expected a Standard Schema (zod, arktype, or valibot)` |
### State schemas must not transform
Reintersect stores block state as JSON and Standard Schema has no encode step, so a state schema's
input and output types must be the same. A transform such as parsing a string into a `Date` is a
type error:
```text theme={null}
Block state is stored as JSON and Standard Schema has no encode step: the state schema must not transform values (its input and output types differ)
```
Keep dates as ISO strings in state and parse them where you use them. Effect Schema can transform
state, because it encodes back to JSON before Reintersect stores it.
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