event-streaming.md

Event Streaming

stream_prompt returns a Ruby Enumerator. Events are string-keyed hashes that mirror JSON-RPC payloads and include snake-case aliases for common camel-case fields.

sdk.stream_prompt("Run the tests and summarize failures").each do |event|
  case event["type"]
  when "message_update"
    print event["delta"]
  when "tool_start"
    warn "Running #{event["tool_name"]}"
  when "permission_request"
    sdk.allow_permission(event["request_id"], scope: :once)
  end
end

Common event types:

• agent_start
• agent_end
• turn_start
• turn_end
• message_start
• message_update
• message_end
• tool_start
• tool_update
• tool_end
• permission_request
• directory_access_request
• file_modified
• changes_batch_start
• changes_batch_update
• changes_batch_end
• error

The SDK emits an agent_end event after turn_end so stream consumers have a stable completion marker.