# Coordination Surface

> A formal definition of a file that parties read and write to coordinate work, carrying a declared key and scope in its header and records each owned by one writer.

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

Listed in [Lexicon terms](https://banes-lab.com/api/records/lexicon.md), after [Shared Technical Concerns](https://banes-lab.com/records/lexicon/shared-technical-concerns.md) and before [Coordination Record](https://banes-lab.com/records/lexicon/coordination-record.md).

## Category

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

## Required by

- [Stated Invariant](https://banes-lab.com/records/architecture/stated-invariant.md)
- [Write Barrier](https://banes-lab.com/records/architecture/write-barrier.md)
- [Two-Direction Index](https://banes-lab.com/records/architecture/two-direction-index.md)
- [State-Arity Limit](https://banes-lab.com/records/architecture/state-arity-limit.md)

## Linked from

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

## Evidence in the code

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