# Postgres

> Tag 0: the server announces a database connection the container’s driver opened, under a connection id it minted; the client answers with everything the database says, which the server writes to the driver, and its channel response finish closes the driver’s socket.

Canonical: https://protocol.diverge.network/2.3.0/container-proxy-endpoints/agents-begin/server/postgres/
Specification revision: 2.3.0

The server opens this channel when a program in the container opens a
connection to the server's database listener. It is the server's half
of the connection; the client's half is a
[postgres](/2.3.0/container-proxy-endpoints/agents-begin/client/postgres/) channel the client opens,
quoting the same id.

- **The request.** The tag byte `0` followed by a connection id, four
  bytes, that the server minted. [Request](/2.3.0/container-proxy-endpoints/agents-begin/server/postgres/request/)
  states its form.
- **The response.** What the database says, as channel responses,
  and the channel response finish, which closes the driver's socket.
  [Response](/2.3.0/container-proxy-endpoints/agents-begin/server/postgres/response/) states the sequence.
- **The id.** The server chooses the id and keeps it unique among the
  connections it has announced and the client has not finished. The
  proxy does not reuse an id while either half of its connection is
  open.
- **Before the other half.** The server reads nothing from the driver
  until the client has opened its half. The server writes what arrives
  on this channel to the driver in order, and does not read it.