> ## Documentation Index > Fetch the complete documentation index at: https://doc.lucidworks.com/llms.txt > Use this file to discover all available pages before exploring further. # Retrieve an index stage > Fetch an index stage by type. The response is the index stage schema in JSON format. ## OpenAPI ````yaml /api-reference/5.9/fusion-api-indexing.json get /index-stages/schema/{type} openapi: 3.0.1 info: title: Fusion Indexing API description: |- The Lucidworks Fusion Indexing API manages parsers, index pipelines, index stages, index profiles, and subscriptions. contact: name: Lucidworks url: https://www.lucidworks.com email: support@lucidworks.com license: name: License of API url: https://lucidworks.com/legal/developer-license-agreement/ version: '5.9' servers: - url: https://{FUSION HOST}/api description: Fusion variables: FUSION HOST: default: FUSION_HOST description: 'Your environment host. ' - url: https://{FUSION HOST}/api/apps/{APP_NAME} description: Fusion app variables: FUSION HOST: default: FUSION_HOST description: 'Your environment host. ' APP_NAME: default: APP_NAME description: The name of your Fusion application. security: - Basic auth: [] - API key: [] tags: - name: Index Pipelines API description: >- Use these endpoints to view and manage your index pipelines. You can also index documents using this API, though the Index Profiles API is recommended instead. - name: Index Profiles API description: >- The Index Profiles API provides static endpoints that you can consistently point to when indexing your documents. Index profiles allow you to change the index pipelines, parsers, or collections behind them without changing the endpoint you use for indexing. See the Index Profiles CRUD API for endpoints that create and modify index profiles. - name: Index Profiles CRUD API description: >- Use these endpoints to create and modify index profiles. Index profiles allow you to change the index pipelines, parsers, or collections behind them without changing the endpoint you use for indexing. See the Index Profiles API for the indexing endpoints. - name: Index Stage API description: >- Use these endpoints to view the available index pipeline stages and their configuration parameters. - name: Index Stage Plugins API description: >- Use these endpoints to view, install, and manage custom index stages developed with the Index Stage SDK. - name: Parsers CRUD API description: >- Endpoints to perform Create-Read-Update-Delete operations on Parsers, Deprecated: use async-parsing endpoint instead. - name: Parsers Schema API description: >- Endpoints to get the Schema of Parsers. Deprecated: use async-parsing endpoint instead. - name: Subscriptions API description: The Subscriptions API externalDocs: description: Lucidworks Documentation url: https://doc.lucidworks.com/ paths: /index-stages/schema/{type}: get: tags: - Index Stage API summary: Retrieve an index stage description: >- Fetch an index stage by type. The response is the index stage schema in JSON format. operationId: getStageSchema parameters: - name: type description: The name of the index stage. in: path required: true schema: type: string example: regex-extractor responses: '200': description: OK content: application/json: schema: $ref: '#/components/schemas/ObjectType' example: type: object title: Regex Field Extraction description: >- This stage allows you to extract entities using regular expressions properties: rules: type: array title: Regex Rules items: type: object required: - pattern properties: source: type: array title: Source Fields items: type: string target: type: string title: Target Field pattern: type: string title: Regex Pattern format: regex annotateAs: type: string title: Annotation Name components: schemas: ObjectType: description: Configuration properties. type: object properties: type: type: string enum: - string - number - integer - boolean - object - array - 'null' - ref title: type: string description: type: string required: uniqueItems: true type: array items: type: string properties: type: object additionalProperties: $ref: '#/components/schemas/AnyType' additionalProperties: type: object minProperties: type: integer format: int32 maxProperties: type: integer format: int32 definitions: type: object additionalProperties: $ref: '#/components/schemas/AnyType' category: type: string categoryPriority: type: integer format: int32 hints: uniqueItems: true type: array items: type: string unsafe: type: boolean default: type: object oneOf: type: array items: $ref: '#/components/schemas/AnyTypeObjectObject' propertyGroups: type: array items: $ref: '#/components/schemas/PropertyGroup' AnyType: description: Configuration properties. type: object properties: type: type: string enum: - string - number - integer - boolean - object - array - 'null' - ref title: type: string description: type: string default: type: object category: type: string categoryPriority: type: integer format: int32 hints: uniqueItems: true type: array items: type: string unsafe: type: boolean oneOf: type: array items: $ref: '#/components/schemas/AnyTypeObjectObject' AnyTypeObjectObject: description: Configuration properties. type: object properties: type: type: string enum: - string - number - integer - boolean - object - array - 'null' - ref title: type: string description: type: string default: type: object category: type: string categoryPriority: type: integer format: int32 hints: uniqueItems: true type: array items: type: string unsafe: type: boolean PropertyGroup: type: object properties: label: type: string properties: type: array items: type: string securitySchemes: Basic auth: type: http scheme: basic API key: name: x-api-key type: apiKey in: header ````