# `Runic.Workflow.FanIn`
[🔗](https://github.com/zblanco/runic/blob/main/lib/workflow/fan_in.ex#L1)

FanIn steps are part of a reduce operator that combines multiple facts into a single fact
by applying the reducer function to return the accumulator with the parent.

## Options

- `:mergeable` - When `true`, indicates this fan-in's reducer has CRDT-like
  properties (commutative, idempotent, associative) and is safe for parallel merge
  without ordering guarantees. Defaults to `false`.

## Runtime Context

FanIn supports `meta_refs` for `context/1` when used as part of a reduce
operation. The `has_meta_refs?/1` function indicates whether context
references are present.

# `has_meta_refs?`

Returns whether this FanIn has meta references (e.g., `context/1`)
that need to be resolved during the prepare phase.

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*Consult [api-reference.md](api-reference.md) for complete listing*