> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-fix-nav-issues.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

> Documentation for the native TCP interface in ClickHouse

# Native interface (TCP)

The native protocol is used in the [command-line client](/concepts/features/interfaces/cli), for inter-server communication during distributed query processing, and also in some language clients (e.g. [clickhouse-go](/integrations/language-clients/go/index#connection-details)).

ClickHouse provides official specifications for the native protocol and the columnar format it carries:

* [Native Protocol](/reference/interfaces/specs/NativeProtocol) — packet framing, the connection state machine, version negotiation, and the body of every non-`Block` message.
* [Native Format](/reference/interfaces/specs/NativeFormat) — the `Block` and column structure, the per-type encodings, and the compression frame. This format also appears outside the TCP protocol, for example with `FORMAT Native` over HTTP.