ai.stream.ContentSeen

Non-empty content that is not assistant text: a reasoning or tool-input delta, or a complete tool-call or file part. There is nothing to deliver to the caller, but the model is producing output, which is what `first_token_timeout` and `stream_token_timeout` measure. A decoder yields it for every content-bearing event that produces no TextDelta; events that carry no content (`message_start`, `response.created`, pings, usage-only frames, empty deltas) yield nothing.

Reference version

Signature

class ai.stream.ContentSeen

Non-empty content that is not assistant text: a reasoning or tool-input delta, or a complete tool-call or file part. There is nothing to deliver to the caller, but the model is producing output, which is what first_token_timeout and stream_token_timeout measure. A decoder yields it for every content-bearing event that produces no TextDelta; events that carry no content (message_start, response.created, pings, usage-only frames, empty deltas) yield nothing.

Source:<builtin>/ai/ns_stream/stream.bamlbytes 5616–5637