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    Pythonlanggraph.prebuilttool_nodeToolRuntimeemit_output_delta
    Method●Since v1.1

    emit_output_delta

    Stream a partial output chunk on the tools stream channel.

    Reads the per-tool-call writer that StreamToolCallHandler installs on a ContextVar at on_tool_start and forwards delta through it. Silent no-op when the graph was not run with "tools" in stream_mode (no writer is set), so tool authors can leave emit_output_delta calls in place without gating them on stream mode.

    Copy
    emit_output_delta(
        self,
        delta: Any,
    ) -> None

    Parameters

    NameTypeDescription
    delta*Any

    Partial output chunk. Any JSON-serializable value; surfaced as-is on the tools channel's tool-output-delta payload under "delta".

    View source on GitHub