# Fan-In

> A measure of how many parties' claims rest on one surface, read from who authored each claim, whom it addressed and which surfaces it cites.

Record: `lexicon:fan-in`
Kind: metric
Layer: [Execution Core](https://banes-lab.com/records/layer/execution-core.md)
Canonical: https://banes-lab.com/ontology/lexicon#lexicon-fan-in

Listed in [Lexicon terms](https://banes-lab.com/api/records/lexicon.md), after [Concern Partition](https://banes-lab.com/records/lexicon/concern-partition.md) and before [Acknowledger](https://banes-lab.com/records/lexicon/acknowledger.md).

## Category

- [Coordination Surfaces](https://banes-lab.com/records/lexicon-category/coordination-surfaces.md)

## Required by

- [Fan-In Ceiling](https://banes-lab.com/records/architecture/fan-in-ceiling.md)

## Linked from

- [Anti-patterns](https://banes-lab.com/ontology/principles/architecture-category-anti-patterns.md)
- [Coordination Surfaces](https://banes-lab.com/ontology/principles/architecture-category-coordination-surfaces.md)

## Evidence in the code

- [models/coupling.model.md](https://banes-lab.com/source/coordination/models/coupling.model.md.md)