> For the complete documentation index, see [llms.txt](/llms.txt)

# SDK Maintainers

Migration guide for SDK maintainers and library authors upgrading to 2.0



# Upgrading SDKs to @mysten/sui\@2.0.0 [#upgrading-sdks-to-mystensui200]

This guide covers the key breaking changes for SDK maintainers building on top of `@mysten/sui`.

For comprehensive SDK development patterns, see the [Building SDKs guide](/sui/sdk-building).

## Use `ClientWithCoreApi` [#use-clientwithcoreapi]

Accept `ClientWithCoreApi` instead of `SuiClient` so applications can pass a `SuiGrpcClient`,
`SuiGraphQLClient`, or a legacy `SuiJsonRpcClient` during migration:

```diff
- import { SuiClient } from '@mysten/sui/client';
+ import type { ClientWithCoreApi } from '@mysten/sui/client';

export class MySDKClient {
-   client: SuiClient;
+   client: ClientWithCoreApi;
}
```

## Access data through `client.core` methods [#access-data-through-clientcore-methods]

SDKs should access shared client methods through `client.core`. Application code can use the same
methods at the top level of its concrete client, but `client.core` is the stable contract for
libraries that should work across transports:

```diff
- const result = await this.client.getObject({ objectId });
+ const result = await this.client.core.getObject({ objectId });

- const result = await this.client.getOwnedObjects({ owner });
+ const result = await this.client.core.listOwnedObjects({ owner });
```

| v1.x Method                      | v2.0 Method                                                              |
| -------------------------------- | ------------------------------------------------------------------------ |
| `client.getObject()`             | `client.core.getObject()`                                                |
| `client.getOwnedObjects()`       | `client.core.listOwnedObjects()`                                         |
| `client.getDynamicFieldObject()` | `client.core.getDynamicField()` or `client.core.getDynamicObjectField()` |
| `client.getDynamicFields()`      | `client.core.listDynamicFields()`                                        |
| `client.multiGetObjects()`       | `client.core.getObjects()`                                               |

Use `getDynamicField()` for regular dynamic fields and when you need the field entry or BCS-encoded
value. Use `getDynamicObjectField()` only for dynamic object fields when you want the referenced
child object returned directly.

See the [Core API documentation](/sui/clients/core) for all available methods.

## Use peer dependencies [#use-peer-dependencies]

Declare `@mysten/*` packages as peer dependencies:

```json
{
	"peerDependencies": {
		"@mysten/sui": "^2.0.0"
	},
	"devDependencies": {
		"@mysten/sui": "^2.0.0"
	}
}
```

## Client extensions [#client-extensions]

v2.0 introduces client extensions that let users add your SDK to any Sui client:

```typescript
import type { ClientWithCoreApi } from '@mysten/sui/client';

export function mySDK() {
	return {
		name: 'mySDK',
		register: (client: ClientWithCoreApi) => {
			return new MySDKClient({ client });
		},
	};
}

// Users can then extend any client
const client = new SuiGrpcClient({ ... }).$extend(mySDK());
await client.mySDK.doSomething();
```

See the [Building SDKs guide](/sui/sdk-building#client-extensions) for the complete extension
pattern.

## Code generation [#code-generation]

Use [`@mysten/codegen`](/codegen) to generate type-safe TypeScript bindings from your Move packages.
See the [codegen documentation](/codegen) for setup instructions.

For complete SDK development patterns including client extensions, transaction thunks, and best
practices, see the [Building SDKs guide](/sui/sdk-building).