> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.nvidia.com/nemo/relay/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.nvidia.com/nemo/relay/_mcp/server.

# Function event

> Emit a standalone mark event under the current or provided scope.

Generated from `cargo doc --no-deps -p nemo-relay -p nemo-relay-adaptive -p nemo-relay-ffi`.

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Emit a standalone mark event under the current or provided scope.

This creates a point-in-time lifecycle event without pushing or popping a new scope.

## Parameters

* `name`: Event name to emit.
* `parent`: Optional explicit parent scope. When `None`, the current top of stack is used.
* `data`: Optional JSON payload recorded on the emitted event.
* `metadata`: Optional JSON metadata recorded on the emitted event.
* `timestamp`: Optional timestamp recorded on the emitted mark event. When `None`, the current UTC time is used.

## Returns

A [`Result`](/reference/api/rust-library-reference/nemo-relay/error/type-result) that is `Ok(())` after the event has been emitted.

## Errors

Returns an error when the runtime owner check fails or when internal state cannot be read safely.

## Notes

Scope-local subscribers attached to ancestor scopes observe the emitted mark event just like scope, tool, and LLM lifecycle events.