SDK event-stream HTTP handler

hastekit.NewHTTPHandler accepts SDK AgentInput JSON and emits SDK response chunks as server-sent events. Use AG-UI for the embedded UI, thread APIs, namespace resolution, and reconnect support.

Register and mount

Given an initialized agent and mux:

registry := hastekit.NewRegistry()
if err := registry.Register(agent); err != nil { return err }
mux.Handle("POST /agent", hastekit.NewHTTPHandler(registry))

The method restriction is on your mux. The handler selects the agent from the agent query parameter:

curl -N http://localhost:8080/agent?agent=assistant   -H 'Content-Type: application/json'   -d '{"namespace":"default","thread_id":"thread-1","messages":{"messages":[{"role":"user","content":"Hello"}]}}'

messages is a message bundle containing an inner message list. This body is not the AG-UI RunAgentInput shape.

Stream handling

Each event has an event name from the SDK chunk type and a JSON data payload. Handle error events even after HTTP 200. A closed stream alone does not prove the model completed successfully. The adapter uses detached agent.Execute execution. Losing the HTTP connection disconnects the subscriber; it does not automatically stop the run. Use an application stop endpoint or the AG-UI handler when clients need run controls.

Application boundary

Wrap this handler with authentication, authorization, request-body limits, and appropriate server timeouts. In particular, the SDK-native input accepts namespace and run-context fields: a public caller must not be allowed to choose privileged values unchecked. This minimal handler does not implement the AG-UI namespace resolver. Registry names are unique within one registry. Registration does not start an HTTP server or durable worker, and does not make the agent discoverable in other processes.

Getting started

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Durable execution

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Testing and operations

SDK event-stream HTTP handler

Register and mount

Stream handling

Application boundary

​Register and mount

​Stream handling

​Application boundary

Register and mount

Stream handling

Application boundary