> ## Documentation Index > Fetch the complete documentation index at: https://docs.lerian.studio/llms.txt > Use this file to discover all available pages before exploring further. # Preview a template > Renders template markup against caller-supplied sample data and returns the output, without creating a template or generating a report. A Pdf template previews as the HTML stage that would feed the PDF engine. The whole request body is capped at 3211264 bytes and a larger one is refused with 413 before it is parsed; content and sampleData carry their own ceilings. ## OpenAPI ````yaml /pt/openapi/v3-current/reporter.yaml post /v1/templates/preview openapi: 3.1.0 info: contact: name: Discord community url: https://discord.gg/DnhqKwkGv3 description: >- This is OpenAPI documentation for Reporter. The unified reporter binary serves the REST API (RUN_MODE=api) and/or the RabbitMQ report-generation worker (RUN_MODE=worker); RUN_MODE=all runs both in one process for local development. All REST endpoints documented here serve only when RUN_MODE=api or all (port :4005); the worker (port :4006) exposes health/readyz/version only. license: name: Lerian Studio General License title: Midaz Reporter API version: 4.0.0 servers: - url: http://localhost:4005 - url: https://localhost:4005 security: - BearerAuth: [] tags: - description: Generated report instances and their lifecycle. name: Reports - description: Reusable report definitions. name: Templates - description: Interactive construction of report templates. name: Template Builder - description: Scheduled report due-date tracking. name: Deadlines - description: Configured inputs that feed report data. name: Data Sources - description: Aggregated reporting metrics. name: Metrics - description: Published business event catalog and delivery policies. name: Streaming paths: /v1/templates/preview: post: tags: - Templates summary: Preview a template description: >- Renders template markup against caller-supplied sample data and returns the output, without creating a template or generating a report. A Pdf template previews as the HTML stage that would feed the PDF engine. The whole request body is capped at 3211264 bytes and a larger one is refused with 413 before it is parsed; content and sampleData carry their own ceilings. operationId: previewTemplate requestBody: content: application/json: schema: $ref: '#/components/schemas/PreviewTemplateInput' description: Template markup and the sample data to render it against. required: true responses: '200': content: application/json: schema: $ref: '#/components/schemas/PreviewTemplateResult' description: OK '400': content: application/problem+json: schema: $ref: '#/components/schemas/Detail' description: Bad Request '401': content: application/problem+json: schema: $ref: '#/components/schemas/Detail' description: Unauthorized '403': content: application/problem+json: schema: $ref: '#/components/schemas/Detail' description: Forbidden '413': content: application/problem+json: schema: $ref: '#/components/schemas/Detail' description: Request Entity Too Large '429': content: application/problem+json: schema: $ref: '#/components/schemas/Detail' description: Too Many Requests '500': content: application/problem+json: schema: $ref: '#/components/schemas/Detail' description: Internal Server Error components: schemas: PreviewTemplateInput: additionalProperties: false properties: content: description: >- Raw pongo2 template markup to render. At most 512 KiB, measured on the decoded bytes. examples: - 'Total: {{ ledger.accounts.0.balance }}' maxLength: 524288 type: string outputFormat: description: >- One of Html, Csv, Txt, Xml or Pdf, matched case-insensitively. Decides the response content type only; defaults to Html when omitted or empty. examples: - Html pattern: >- ^([Hh][Tt][Mm][Ll]|[Cc][Ss][Vv]|[Tt][Xx][Tt]|[Xx][Mm][Ll]|[Pp][Dd][Ff])?$ type: string sampleData: additionalProperties: additionalProperties: items: additionalProperties: {} type: object type: - array - 'null' type: object description: >- Render context shaped as data source, then table, then rows. At most 1 MiB, measured on the raw JSON bytes sent for this member. type: object required: - content type: object PreviewTemplateResult: additionalProperties: false properties: contentType: description: Content type the rendered output should be displayed as. examples: - text/html type: string durationMs: description: How long the preview took, in milliseconds. examples: - 12 format: int64 type: integer rendered: description: >- Rendered output. For a Pdf template this is the HTML stage that would feed the PDF engine. examples: - 'Total: 1500.00' type: string warnings: description: Non-fatal render notes, such as output having been truncated. items: type: string type: array required: - rendered - contentType - warnings - durationMs type: object Detail: properties: code: description: >- Stable, machine-readable domain error code scoped to the emitting service (format: -NNNN). type: string detail: description: >- A human-readable explanation specific to this occurrence of the problem. examples: - Property foo is required but is missing. type: string errors: description: Optional list of individual error details examples: - - location: body.templateId message: expected string to match 'uuid' format value: not-a-uuid items: $ref: '#/components/schemas/ErrorDetail' type: - array - 'null' instance: description: >- A URI reference that identifies the specific occurrence of the problem. examples: - https://example.com/error-log/abc123 format: uri type: string status: description: HTTP status code examples: - 400 format: int64 type: integer title: description: >- A short, human-readable summary of the problem type. This value should not change between occurrences of the error. examples: - Bad Request type: string type: default: about:blank description: A URI reference to human-readable documentation for the error. examples: - https://example.com/errors/example format: uri type: string upstream: $ref: '#/components/schemas/Upstream' description: >- RFC 9457 extension member: the error a proxied third-party provider reported. Absent unless the emitting service explicitly surfaced one. type: object ErrorDetail: properties: location: description: >- Where the error occurred, e.g. 'body.items[3].tags' or 'path.thing-id' examples: - body.templateId type: string message: description: Error message text examples: - expected string to match 'uuid' format type: string value: description: The value at the given location examples: - not-a-uuid type: object Upstream: additionalProperties: false properties: code: description: The upstream provider's own error code, verbatim. examples: - E4001 type: string message: description: >- The upstream provider's own error message, verbatim (bounded, never its raw response body). examples: - account not found at provider type: string type: object securitySchemes: BearerAuth: bearerFormat: JWT description: JWT bearer token issued by the identity provider. scheme: bearer type: http ````