---
meta:
  title: "The type you provided for 'RoomInfo' does not match its requirements"
  parentTitle: "Error"
  description: "Your 'RoomInfo' type is incorrect and needs to be updated"
---

## Why this error occurred

You have provided a custom `RoomInfo` type for your application, but the type
you provided isn’t a (completely) valid definition.

```ts highlight="4-10"
declare global {
  interface Liveblocks {
    RoomInfo: {
      // Your custom fields go here...
      name: string;
      url: URL; // ❌ The issue is here
      geo: {
        city: string;
        country: string;
      };
    };
  }
}
```

In the example above, the problem is the `URL` field. Values like `Date`, `Map`,
`Set`, functions, classes (including `URL`), or `unknown` aren’t valid JSON.

## The rules of the RoomInfo type

The following rules apply if you want to specify a custom `RoomInfo` type:

- You can provide any keys and values here, as long as the values are valid
  JSON.
- Two small constraints:
  - _If_ you specify `name`, it _must_ be assignable to `string | undefined`.
  - _If_ you specify `url`, then it _must_ be assignable to
    `string | undefined`.

The reason for these two restrictions is that some of our higher-level
components will pick these values up and use them to provide default UIs.

## How to fix it

You’ll need to figure out what part of your provided `RoomInfo` type definition
isn’t valid. The example above can be fixed as follows:

```tsx
declare global {
  interface Liveblocks {
    RoomInfo: {
      // Your custom fields go here...
      name: string;
      url: string; // ✅ Valid
      geo: {
        city: string;
        country: string;
      };
    };
  }
}
```

## If you cannot find the root cause

Sometimes types can be complex and the root cause is still unclear. In those
cases, there is a small trick you can use. Try to assign your type to the
required base type, with this line:

```ts highlight="9-10"
import type { BaseRoomInfo } from "@liveblocks/client";

declare global {
  interface Liveblocks {
    RoomInfo: MyRoomInfo;
  }
}

// Quick debugging snippet to find root cause
const xxx: BaseRoomInfo = {} as MyRoomInfo;
//    ^?
//    The error will appear here
```

Now TypeScript will explain why it thinks your type isn’t valid room info:

```error showLineNumbers={false}
Type 'MyRoomInfo' is not assignable to type 'BaseRoomInfo'.
  Types of property 'url' are incompatible.
    Type 'URL' is not assignable to type 'string'.
```

---

For an overview of all available documentation, see [/llms.txt](/llms.txt).