# Native TCP interface

The native interface provides a stateful CoordinatorDB connection. Its default listener is `127.0.0.1:7400`.

Use the supplied client. ClickHouse, PostgreSQL and SQLite wire clients are not compatible with the native protocol.

## Authentication and state

Every connection authenticates a configured username and password before SQL is accepted. It retains the selected database, transaction state and temporary objects until disconnection.

The native API can also carry positional values beside the SQL text. Those values are excluded from the logged SQL text.

## Transport and limits

Native transport has no TLS. Use trusted connectivity or an external secure tunnel for credentials in transit.

Ordinary SQL/control requests and responses are limited to 16 MiB. Client stdin and INFILE uploads have no total input-size ceiling; admission, response and request-processing limits still apply.

## Client

Use [the native client](https://coordinatordb.com/docs/concepts/features/interfaces/client) for interactive SQL, exact-byte output and file input. See [network settings](https://coordinatordb.com/docs/concepts/features/security/network-ports) for listener overrides and [transactions](https://coordinatordb.com/docs/concepts/features/operations/insert/transactions) for connection lifetime.