AsyncAPI channel · Optimism · Optimism (OP Stack) WebSocket JSON-RPC API

eth_subscribe.newHeads

Subscription that pushes a notification each time a new block header is added to the chain. Standard op-geth (upstream go-ethereum) behaviour; the OP Stack does not add custom fields to the header itself, though consumers should expect L2-specific block production cadence (~2s on OP Mainnet, faster with Flashblocks preconfirmations).

Open source AsyncAPI → All Optimism channels Optimism provider profile
Provider: Optimism AsyncAPI: v2.6.0 Spec: Optimism (OP Stack) WebSocket JSON-RPC API Operations: 2 Messages: 3

Channel address

eth_subscribe.newHeads

Operations

publish
subscribeNewHeads
Subscribe to new block headers (`eth_subscribe("newHeads")`).
onNewHead
Receive a notification for each new block header.

Messages

SubscribeNewHeadsRequest
JSON-RPC request to subscribe to new block headers.
Content-Type: application/json
SubscribeResponse
JSON-RPC response containing the subscription id.
Content-Type: application/json
NewHeadNotification
Notification carrying a new block header.
Content-Type: application/json

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The AsyncAPI specification describes event-driven APIs the way OpenAPI describes request/response APIs. A channel is the named pipe — a webhook URL, a Kafka topic, a WebSocket route, an MQTT subject — that producers and consumers publish or subscribe to. Each channel carries one or more messages with structured payloads, and an operation declares whether a given party sends or receives on that channel.

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