> ## Documentation Index > Fetch the complete documentation index at: https://docs.omneo.io/llms.txt > Use this file to discover all available pages before exploring further. # Preview a Target Template > A `POST` to the `/targets/preview` endpoint processes a Twig template against a chosen resource and returns the rendered payload. The template is rendered, then parsed as JSON, so `data.result` is the decoded JSON object (not a string) and `data.context` is the resource context the template was rendered against. Provide either an inline `template` or a `target_id` (one is required). If both are sent, the inline `template` takes precedence. If the Twig fails to render, or its output is not valid JSON, the request returns `422` with a captured `error` object (`stage`, `message`, `line`). When the failure is a JSON-parse error (`stage` is `json`), the raw rendered output is also returned as `rendered_raw` so you can see what the template produced. ## OpenAPI ````yaml post /v3/targets/preview openapi: 3.1.0 info: title: Omneo version: 0.0.1 servers: - url: https://api.{tenant}.getomneo.com/api variables: tenant: default: example security: [] paths: /v3/targets/preview: post: tags: - Target summary: Preview a Target Template description: >- A `POST` to the `/targets/preview` endpoint processes a Twig template against a chosen resource and returns the rendered payload. The template is rendered, then parsed as JSON, so `data.result` is the decoded JSON object (not a string) and `data.context` is the resource context the template was rendered against. Provide either an inline `template` or a `target_id` (one is required). If both are sent, the inline `template` takes precedence. If the Twig fails to render, or its output is not valid JSON, the request returns `422` with a captured `error` object (`stage`, `message`, `line`). When the failure is a JSON-parse error (`stage` is `json`), the raw rendered output is also returned as `rendered_raw` so you can see what the template produced. operationId: target.preview requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/PreviewTarget' responses: '200': description: >- The rendered, JSON-decoded template and the context it was rendered against. content: application/json: schema: type: object properties: data: type: object properties: result: type: object additionalProperties: {} description: The rendered template output, parsed as a JSON object. context: type: object additionalProperties: {} description: >- The resource context the template was rendered against. required: - result - context required: - data '401': $ref: '#/components/responses/AuthenticationException' '403': $ref: '#/components/responses/AuthorizationException' '404': description: The requested resource could not be found. content: application/json: schema: type: object properties: error: type: object properties: stage: type: string enum: - resource description: Always `resource` for this error. message: type: string description: The captured failure message. line: type: integer nullable: true description: Always null for this error. required: - stage - message - line required: - error '422': description: >- Either request validation failed, or the template failed to render or did not produce valid JSON. content: application/json: schema: oneOf: - type: object title: Render or JSON error description: >- Returned when the Twig template fails to render, or its output is not valid JSON. properties: error: type: object properties: stage: type: string enum: - render - json description: >- Where the failure occurred: `render` for a Twig error, `json` when the output could not be parsed as JSON. message: type: string description: The captured failure message. line: type: integer nullable: true description: >- The template line that failed, when available. Null for JSON errors. required: - stage - message - line rendered_raw: type: string nullable: true description: >- The raw rendered template output. Populated when `stage` is `json`, otherwise null. required: - error - rendered_raw - type: object title: Validation error description: >- Returned when the request body fails validation, for example when neither `template` nor `target_id` is supplied. properties: message: type: string description: Errors overview. errors: type: object description: >- A detailed description of each field that failed validation. additionalProperties: type: array items: type: string required: - message - errors components: schemas: PreviewTarget: type: object description: >- Provide either an inline `template` or a `target_id`. One of the two is required; if both are sent, the inline `template` takes precedence. properties: resource: type: string description: The resource type to render the template against. enum: - profile - transaction - transaction_item - order - order_item - reward resource_id: type: string description: The ID of the resource record to render against. template: type: string description: >- An inline Twig template to render. Required when `target_id` is omitted. target_id: type: integer description: >- The ID of an existing Target whose template to render. Required when `template` is omitted. required: - resource - resource_id anyOf: - required: - template - required: - target_id title: PreviewTarget responses: AuthenticationException: description: Unauthenticated content: application/json: schema: type: object properties: message: type: string description: Error overview. required: - message AuthorizationException: description: Authorization error content: application/json: schema: type: object properties: message: type: string description: Error overview. required: - message ````