# Shared Invocation

> The ability for several callers to share one run of a measurement, each either joining a live run that covers its question or starting one that no live run covers.

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

Listed in [Lexicon terms](https://banes-lab.com/api/records/lexicon.md), after [Governed Removal](https://banes-lab.com/records/lexicon/governed-removal.md) and before [Concern Tag](https://banes-lab.com/records/lexicon/concern-tag.md).

## Category

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

## Enabled by

- [Write Scope and Read Population](https://banes-lab.com/records/architecture/write-scope-and-read-population.md)
- [Read-Time Join](https://banes-lab.com/records/architecture/read-time-join.md)
- [One-Sided Liveness](https://banes-lab.com/records/architecture/one-sided-liveness.md)
- [Declare-Before-Read Order](https://banes-lab.com/records/architecture/declare-before-read-order.md)

## Linked from

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

## Evidence in the code

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