---
title: "ProjectionDefinitionSpecification | JavaScript maps SDK"
description: "Documentation for MapTiler SDK"
---

> For AI agents: a documentation index is available at [/llms.txt](https://docs.maptiler.com/llms.txt). Markdown versions of all pages are available by appending .md to any URL.

# Type Alias ProjectionDefinitionSpecification

ProjectionDefinitionSpecification:  
    | string  
    | [ProjectionDefinitionT](https://docs.maptiler.com/sdk-js/api-reference/types/ProjectionDefinitionT/)  
    | [PropertyValueSpecification](https://docs.maptiler.com/sdk-js/api-reference/types/PropertyValueSpecification/)<[ProjectionDefinitionT](https://docs.maptiler.com/sdk-js/api-reference/types/ProjectionDefinitionT/)\>