> ## Documentation Index > Fetch the complete documentation index at: https://docs.e6data.com/llms.txt > Use this file to discover all available pages before exploring further. # Preview dashboard dataset > preview dashboard dataset. POST /api/v1/dashboards/preview. Execute a read-only dashboard dataset preview with parameters. Returns a session and operation identity; poll operation_ ReferenceApplies to: Unified engine deployments ## Related guidance [Addresses and access](https://docs.e6data.com/transformation/http/access.md) · [Request identity](https://docs.e6data.com/transformation/http/request-identity.md) · [Errors and recovery](https://docs.e6data.com/transformation/http/errors.md) · [Pagination and results](https://docs.e6data.com/transformation/http/results.md) ## OpenAPI ````yaml openapi/transformation.json POST /api/v1/dashboards/preview openapi: 3.1.0 info: description: >- HTTP contracts for the Unified engine. Requests use the connected deployment's access model and configured owner. Response examples are illustrative; inspect your engine response in your client. SQL-managed secrets, credentials, streaming pipelines and maintenance run through session operations. title: Laminar Unified HTTP API version: v1 servers: - url: https://engine.example.com description: >- Example engine origin. Replace it with your deployment URL and any API mount prefix. security: [] paths: /api/v1/dashboards/preview: post: tags: - Dashboards summary: preview dashboard dataset description: >- preview dashboard dataset. POST /api/v1/dashboards/preview. Execute a read-only dashboard dataset preview with parameters. Returns a session and operation identity; poll operation_status then operation_results. This starts engine work. operationId: preview_dashboard_dataset parameters: [] requestBody: content: application/json: schema: additionalProperties: false properties: dataset: additionalProperties: false properties: dataset_id: format: uuid type: string name: type: string settings: additionalProperties: false properties: ansi_enabled: type: boolean case_sensitive: type: boolean current_catalog: type: string namespace: items: type: string type: array time_zone: type: string required: - current_catalog - namespace - time_zone - case_sensitive - ansi_enabled type: object source_query_id: format: uuid type: - string - 'null' sql: type: string required: - dataset_id - name - sql - settings type: object options: additionalProperties: false properties: compute_requirements: anyOf: - additionalProperties: false properties: cpu_millicores: minimum: 1 type: integer memory_bytes: minimum: 1 type: integer tuning: anyOf: - additionalProperties: false properties: batch_rows: maximum: 1048576 minimum: 1 type: - integer - 'null' buffer_bytes: minimum: 1 type: - integer - 'null' file_read_concurrency: maximum: 32 minimum: 1 type: - integer - 'null' input_prefetch_batches: maximum: 32 minimum: 0 type: - integer - 'null' output_buffer_batches: maximum: 32 minimum: 1 type: - integer - 'null' query_memory_bytes: minimum: 1 type: - integer - 'null' spill_bytes: minimum: 0 type: - integer - 'null' threads: minimum: 1 type: - integer - 'null' write_batch_rows: description: >- Sink batch row limit. Defaults to 65536 independently of reader batches. maximum: 1048576 minimum: 1 type: - integer - 'null' write_parallelism: description: >- Concurrent worker-local file writers. Defaults to execution threads and cannot exceed them. minimum: 1 type: - integer - 'null' required: [] type: object - type: 'null' description: >- Optional resource-aware execution overrides; omitted fields scale with CPU and memory. required: - cpu_millicores - memory_bytes type: object - type: 'null' deployment_profile: description: >- Deployment compute pool. Omit to use its default. Cannot combine with provisioner, profile, or compute_requirements. type: - string - 'null' execution_target: enum: - DataFusion - DuckDb - null execution_timeout: anyOf: - additionalProperties: false properties: nanos: maximum: 999999999 minimum: 0 type: integer secs: minimum: 0 type: integer required: - secs - nanos type: object - type: 'null' max_attempts: minimum: 1 type: - integer - 'null' missed_run_policy: enum: - RunOnce - RunAll - Skip - null overlap_policy: enum: - Wait - Skip - Allow - null parallelism: description: >- Maximum concurrent tasks. Unset has no per-run limit. Workload scope reuses workers within the run. Compute requirements apply per worker. maximum: 4294967295 minimum: 1 type: - integer - 'null' profile: description: >- Named compute profile. Do not combine with custom compute_requirements. type: - string - 'null' provisioner: description: Named provisioner. Omit to inherit the instance default. type: - string - 'null' queue_timeout: anyOf: - additionalProperties: false properties: nanos: maximum: 999999999 minimum: 0 type: integer secs: minimum: 0 type: integer required: - secs - nanos type: object - type: 'null' description: >- Optional time to wait after a task enters the execution queue. worker_scope: description: >- Deployment shares startup pools. Workload reuses workers within a run. Task creates a worker for each attempt. enum: - Deployment - Workload - Task - null xray: description: >- Capture detailed performance for this session operation only. Default false. Requires the Xray feature flag. type: boolean required: [] type: object parameter_definitions: additionalProperties: additionalProperties: false properties: default: {} description: type: string enum: type: array nullable: type: boolean required: type: boolean type: enum: - string - integer - decimal - boolean - date - timestamp required: - type type: object type: object parameters: type: object scheduled_at_unix_millis: type: integer submission_id: format: uuid type: string required: - submission_id - dataset - scheduled_at_unix_millis type: object required: true responses: '202': content: application/json: schema: properties: {} type: object description: Successful response. default: content: application/json: example: error: code: invalid_request message: Check the request fields schema: $ref: '#/components/schemas/ApiError' description: A rejected or failed request. Inspect error.code before retrying. components: schemas: ApiError: properties: error: properties: code: type: string message: type: string required: - code - message type: object required: - error type: object ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.