Parsed Streams Reference

API reference for Parsed Streams JSON-RPC methods over WebSocket. Subscribe to decoded Solana transactions with server-side filtering.

Parsed Streams is generally available on all plans. Authenticate with your project’s API key. Each delivered event costs 1 credit; see Credits.

Parsed Streams uses JSON-RPC 2.0 over a single WebSocket connection. Each request receives a response with the same id. A subscription then pushes parsedTransactionNotification messages until you unsubscribe or disconnect.

Method	Purpose
parsedTransactionSubscribe	Start a subscription with a filter
parsedTransactionUnsubscribe	Stop a subscription
describeProgram	List a program’s instructions, events, and account roles

parsedTransactionSubscribe

Subscribe to decoded transactions matching a program, account, and instruction filter.

parsedTransactionUnsubscribe

Stop a subscription by its id.

describeProgram

Discover the exact instruction and role names the matcher compares against.

Connection

Parsed Streams is served on the Gatekeeper endpoint at wss://beta.helius-rpc.com, the same host as Helius RPC and WebSocket traffic. Get your API key from the Helius Dashboard and pass it as the api-key query parameter (or the x-api-key header):

wscat

wscat -c "wss://beta.helius-rpc.com/?api-key=YOUR_API_KEY"

describeProgram is the exception: it is currently only available on wss://fs-beta.helius-rpc.com/?api-key=YOUR_API_KEY.

A missing or invalid key is rejected with HTTP 401. A project at its connection cap gets HTTP 429.

Limits

Limit	Value
Concurrent connections per project	5 (Free), 10 (Developer), 50 (Business and Professional)
Subscriptions per connection	25
Client messages	10 per second, burst of 20
Client message size	64 KiB
programs per filter	10
instructionNames per filter	50, each up to 64 chars
accounts.include per filter	100
accounts.roles per filter	20, each name up to 64 chars
Outbound buffer per connection	2048 notifications, then the connection is closed

Errors

Errors follow JSON-RPC 2.0: { "error": { "code": <int>, "message": "<text>" }, "id": <id> }. Messages say exactly what was wrong and where.

Code	Meaning
-32700	Parse error (invalid JSON)
-32600	Invalid request
-32601	Method not found
-32602	Invalid params: bad pubkey, unknown field, unsupported commitment or details value
-32000	Filter limit exceeded
-32001	Server not ready; retry with backoff
-32002	Rate limited (10 messages per second)
-32006	Too many subscriptions (25 per connection)

Connections can also close with a WebSocket close code — see Handling Reconnects for what each one means and how to recover.

Learn more

Parsed Streams Overview

What Parsed Streams is and the mental model behind filters.

Quickstart

Connect, send your first filter, and read a decoded notification.

Parsed Events Reference

Query the same decoded transactions on demand through REST.

Handling Reconnects

Survive idle timeouts and deploys, then backfill exactly what you missed.