# Interface: TRPCConnectionParamsMessage

> 

Defined in: [packages/server/src/unstable-core-do-not-import/rpc/envelopes.ts:187](https://github.com/trpc/trpc/blob/7c907acfd8b31929214792e3b8c2ad7a8ac72563/packages/server/src/unstable-core-do-not-import/rpc/envelopes.ts#L187)

The connection params a WebSocket client sends as its first message.

## See

https://trpc.io/docs/server/websockets#connection-params

## Extends

- [`BaseRequest`](https://trpc.io/docs/typedoc/server/rpc/namespaces/JSONRPC2/interfaces/BaseRequest.md)\<`"connectionParams"`\>

## Properties

### data

> **data**: `null` \| [`Dict`](https://trpc.io/docs/typedoc/server/index/type-aliases/Dict.md)\<`string`\>

Defined in: [packages/server/src/unstable-core-do-not-import/rpc/envelopes.ts:188](https://github.com/trpc/trpc/blob/7c907acfd8b31929214792e3b8c2ad7a8ac72563/packages/server/src/unstable-core-do-not-import/rpc/envelopes.ts#L188)

***

### id?

> `optional` **id**: [`RequestId`](https://trpc.io/docs/typedoc/server/rpc/namespaces/JSONRPC2/type-aliases/RequestId.md)

Defined in: [packages/server/src/unstable-core-do-not-import/rpc/envelopes.ts:29](https://github.com/trpc/trpc/blob/7c907acfd8b31929214792e3b8c2ad7a8ac72563/packages/server/src/unstable-core-do-not-import/rpc/envelopes.ts#L29)

#### Inherited from

[`BaseRequest`](https://trpc.io/docs/typedoc/server/rpc/namespaces/JSONRPC2/interfaces/BaseRequest.md).[`id`](https://trpc.io/docs/typedoc/server/rpc/namespaces/JSONRPC2/interfaces/BaseRequest.md#id)

***

### jsonrpc?

> `optional` **jsonrpc**: `"2.0"`

Defined in: [packages/server/src/unstable-core-do-not-import/rpc/envelopes.ts:30](https://github.com/trpc/trpc/blob/7c907acfd8b31929214792e3b8c2ad7a8ac72563/packages/server/src/unstable-core-do-not-import/rpc/envelopes.ts#L30)

#### Inherited from

[`BaseRequest`](https://trpc.io/docs/typedoc/server/rpc/namespaces/JSONRPC2/interfaces/BaseRequest.md).[`jsonrpc`](https://trpc.io/docs/typedoc/server/rpc/namespaces/JSONRPC2/interfaces/BaseRequest.md#jsonrpc)

***

### method

> **method**: `"connectionParams"`

Defined in: [packages/server/src/unstable-core-do-not-import/rpc/envelopes.ts:36](https://github.com/trpc/trpc/blob/7c907acfd8b31929214792e3b8c2ad7a8ac72563/packages/server/src/unstable-core-do-not-import/rpc/envelopes.ts#L36)

#### Inherited from

[`BaseRequest`](https://trpc.io/docs/typedoc/server/rpc/namespaces/JSONRPC2/interfaces/BaseRequest.md).[`method`](https://trpc.io/docs/typedoc/server/rpc/namespaces/JSONRPC2/interfaces/BaseRequest.md#method)