Seamless Onboarding for Postgres Binary Protocol Proxying

The first connection request hit the server, and nothing could be left to chance. The onboarding process for Postgres binary protocol proxying must be exact, fast, and secure, or the entire stack risks instability before the first query runs.

Postgres speaks its own binary protocol. It is efficient and precise, but also unforgiving. When building a proxy that handles this protocol, onboarding is more than just opening a socket and forwarding bytes. It is about capturing the handshake, parsing the startup packet, and ensuring proper negotiation before any command or data exchange. A solid onboarding process sets the stage for reliable, low-latency communication between clients and the backend database.

The first step is intercepting the incoming TCP connection at the proxy layer. Here, the proxy must read the client’s startup message, which includes parameters like user, database, and optional settings. This packet is binary-encoded, so exact parsing according to the Postgres protocol specification is mandatory. Any deviation—a malformed length field, an unsupported parameter—should trigger an immediate, clean shutdown to prevent protocol drift.

Next, the proxy must establish its own backend connection to Postgres, mirroring the initial handshake. This backend connection must pass through authentication. Depending on server configuration, this may involve clear-text passwords, MD5, or SASL mechanisms like SCRAM-SHA-256. The onboarding process should handle these methods transparently, forwarding challenge and response messages without altering payload semantics.

Once authentication completes, parameter status messages and ReadyForQuery must be handled precisely. At this point, the onboarding process transitions from setup to steady-state proxying. This stage locks in the connection’s context, including session defaults, transaction isolation level, and any protocol extensions negotiated during startup.

Performance considerations begin here. The proxy should pre-allocate buffers sized for typical Postgres message frames to reduce allocation overhead. Compression and encryption layers, if applied, must be negotiated as part of onboarding, with clear separation from query-stream forwarding. Logging during onboarding should be verbose for debugging, but switch to minimal overhead mode once the connection is live.

A robust onboarding process for Postgres binary protocol proxying ensures that client expectations match server behavior. It prevents subtle bugs, authentication failures, and race conditions from leaking into production traffic. The payoff is stability: once onboarded cleanly, connections can handle high-throughput workloads without unpredictable breakage.

If you want to see seamless onboarding for Postgres binary protocol proxying in action, try it on hoop.dev and spin up a working proxy in minutes.