Protocol overview

Tessium Streaming API v1 uses JSON messages over one WebSocket connection. One connection can carry multiple independent subscriptions.

Endpoint

wss://api.tessium.dev/stream?key=YOUR_API_KEY

You can also authenticate with the first WebSocket message when keeping the key out of the URL is more convenient:

{ "op": "auth", "key": "tsk_live_..." }

Frame kinds

op	Direction	Purpose
auth	client → server	Authenticate when the key is not in the URL
subscribe	client → server	Open a stream subscription
unsubscribe	client → server	Stop a subscription
ping	client → server	Application-level connection check
ack	server → client	Confirm a command and return the subscription id
pong	server → client	Reply to an application-level ping
event	server → client	Deliver a stream event
error	server → client	Reject a command or report a failure
notice	server → client	Report non-fatal stream state

See Frames for complete command envelopes, Cursor & replay for reconnect behavior, Detail levels for payload tiers, and Errors & notices for every machine-readable code.

Delivery model

• Only successful Solana transactions are streamed.
• Every non-candle event has a common transaction envelope.
• blockTime can be null while block time is not yet available; Tessium does not hold the event back while waiting for it.
• A token subscription and a wallet subscription can both emit an event for the same trade. They are separate subscriptions, not duplicates.
• Client messages are limited to 64 KB.
• Frames are sent uncompressed, so the size you see in an event is the size on the connection.

Keeping the connection alive

The server sends a WebSocket ping every 20 seconds. Most client libraries answer it for you, and as long as something arrives from your side — a pong or any command — the connection stays open.

If nothing arrives for 60 seconds, the connection closes with a ping_timeout notice. The usual cause is not a broken network but a proxy between you and us that swallows protocol-level pings. There is an application-level ping for exactly that case, and it refreshes the same timer:

{ "op": "ping", "id": 3 }

Send it every 30 seconds or so if your library does not answer pings on its own, or if you have seen disconnects you could not explain.

Protocol version: v1. Reference snapshot: 31 July 2026.