> This page is for NeMo Relay, version dev.
> For other versions, use one of these documentation indexes:
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> - v0.11.1: https://docs.nvidia.com/nemo/relay/v0.11.1/llms.txt
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> - v0.9.4: https://docs.nvidia.com/nemo/relay/v0.9.4/llms.txt
> - v0.8.4: https://docs.nvidia.com/nemo/relay/v0.8.4/llms.txt
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# Function llm_stream_call_execute

> Execute a streaming LLM call through the managed middleware pipeline.

Generated from `cargo doc --no-deps -p nemo-relay-builtins -p nemo-relay-diagnostics -p nemo-relay-logging -p nemo-relay-plugin-host -p nemo-relay-codecs -p nemo-relay -p nemo-relay-runtime -p nemo-relay-model-pricing -p nemo-relay-resource-metrics -p nemo-relay-observability -p nemo-relay-adaptive -p nemo-relay-pii-redaction -p nemo-relay-ffi -p nemo-relay-types -p nemo-relay-plugin -p nemo-relay-worker-proto -p nemo-relay-worker`.

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Execute a streaming LLM call through the managed middleware pipeline.

This runs the same pre-execution middleware as [`llm_call_execute`](/reference/api/rust-library-reference/nemo-relay/llm/fn-llm-call-execute), emits the LLM-start event, and then wraps the provider stream so chunk callbacks and finalization can emit a single LLM-end event when streaming completes.

## Parameters

* `name`: Logical provider or model family name recorded on emitted events.
* `request`: Raw [`LlmRequest`](/reference/api/rust-library-reference/nemo-relay/struct-llmrequest) passed into the managed pipeline.
* `func`: Streaming provider callback or execution continuation.
* `collector`: Per-chunk collector callback used to accumulate stream state.
* `finalizer`: Finalizer callback used to construct the completed response.
* `parent`: Optional explicit parent scope for the emitted LLM span.
* `attributes`: LLM attribute bitflags applied to the managed span.
* `data`: Optional application payload stored on the managed LLM handle. It may be used on failure end events that have no output payload.
* `metadata`: Optional JSON metadata recorded on emitted events.
* `model_name`: Optional normalized model name for observability output.
* `codec`: Optional request codec used to produce annotated request data for intercepts and events.
* `response_codec`: Optional response codec used to attach annotated response data to the end event.

## Returns

A [`Result`](/reference/api/rust-library-reference/nemo-relay/type-result) containing a boxed stream of JSON chunks.

## Errors

Returns [`FlowError::GuardrailRejected`](/reference/api/rust-library-reference/nemo-relay/enum-flowerror) when conditional-execution guardrails block the call, or any error raised by request intercepts, execution intercepts, stream callbacks, codecs, or the provider callback.

## Notes

The LLM-start event is emitted before stream execution intercepts run. Before sanitize-request guardrails run, the runtime removes standard credential headers from the event-only request copy; the request passed to stream execution is unchanged.

The returned stream emits chunk-level results while the runtime defers the LLM-end event until the collector and finalizer complete.