> ## Documentation Index > Fetch the complete documentation index at: https://docs.gp.scale.com/llms.txt > Use this file to discover all available pages before exploring further. # Dry-run a custom-function evaluation task > Dry-run a custom-function evaluation task against sample rows to validate it before creating an evaluation. Runs the task's Python scoring function over each row in ``sample_data`` (1-10 rows) and returns a per-row result — ``success`` with the returned ``result`` or an ``error`` — plus the resolved function name and parameters, so a broken function or misconfigured task is caught before it is used in a real evaluation. Nothing is persisted and no evaluation is created; results are returned inline. Only the ``custom_function`` task type is supported; any other ``task_type`` returns 400. The ``configuration`` must be a valid custom-function config: a Python ``function_source`` (up to 10,000 characters), an optional ``arg_mapping`` of function parameters to ``item.`` locators (auto-derived from the function signature when omitted), and optional literal ``config_args``. An invalid configuration or a function that fails to load returns 400; exceeding the dry-run's total time budget returns 408 with whatever rows completed. When two-plane evaluations are enabled for the account the request is proxied to the eval service's control plane. ## OpenAPI ````yaml https://api.sgp.scale.com/openapi-versions/v5/openapi.json post /v5/evaluations/tasks/dry-run openapi: 3.1.0 info: title: EGP API V5 description: >- This is the parent API for all EGP APIs. If you are looking for the EGP API, please go to https://api.egp.scale.com/docs. contact: name: Scale Generative AI Platform url: https://scale.com/genai-platform version: 0.1.0 servers: - url: https://api.egp.scale.com security: [] paths: /v5/evaluations/tasks/dry-run: post: tags: - Evaluations summary: Dry-run a custom-function evaluation task description: >- Dry-run a custom-function evaluation task against sample rows to validate it before creating an evaluation. Runs the task's Python scoring function over each row in ``sample_data`` (1-10 rows) and returns a per-row result — ``success`` with the returned ``result`` or an ``error`` — plus the resolved function name and parameters, so a broken function or misconfigured task is caught before it is used in a real evaluation. Nothing is persisted and no evaluation is created; results are returned inline. Only the ``custom_function`` task type is supported; any other ``task_type`` returns 400. The ``configuration`` must be a valid custom-function config: a Python ``function_source`` (up to 10,000 characters), an optional ``arg_mapping`` of function parameters to ``item.`` locators (auto-derived from the function signature when omitted), and optional literal ``config_args``. An invalid configuration or a function that fails to load returns 400; exceeding the dry-run's total time budget returns 408 with whatever rows completed. When two-plane evaluations are enabled for the account the request is proxied to the eval service's control plane. operationId: POST-V5-/v5/evaluations/tasks/dry-run parameters: - name: x-selected-account-id in: header required: false schema: anyOf: - type: string - type: 'null' title: Account ID Header requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/TaskDryRunRequest' responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/TaskDryRunResponse' '408': content: application/json: schema: $ref: '#/components/schemas/TaskDryRunTimeoutResponse' description: Request Timeout '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' security: - APIKeyHeader: [] components: schemas: TaskDryRunRequest: properties: task_type: $ref: '#/components/schemas/EvaluationTaskType' description: The type of evaluation task to dry-run. configuration: additionalProperties: true type: object title: Configuration description: Task-type-specific configuration. Validated per task_type. sample_data: items: additionalProperties: true type: object type: array maxItems: 10 minItems: 1 title: Sample Data description: Sample data rows to test the task against. type: object required: - task_type - configuration - sample_data title: TaskDryRunRequest TaskDryRunResponse: properties: task_type: $ref: '#/components/schemas/EvaluationTaskType' info: additionalProperties: true type: object title: Info description: Task-type-specific metadata (e.g. function_name, parameters). results: items: $ref: '#/components/schemas/TaskDryRunRowResult' type: array title: Results type: object required: - task_type - results title: TaskDryRunResponse TaskDryRunTimeoutResponse: properties: message: type: string title: Message completed_results: items: $ref: '#/components/schemas/TaskDryRunRowResult' type: array title: Completed Results type: object required: - message - completed_results title: TaskDryRunTimeoutResponse HTTPValidationError: properties: detail: items: $ref: '#/components/schemas/ValidationError' type: array title: Detail type: object title: HTTPValidationError EvaluationTaskType: type: string enum: - chat_completion - inference - application_variant - agentex_output - metric - auto_evaluation.question - auto_evaluation.guided_decoding - auto_evaluation.agent - contributor_evaluation.question - contributor_audit - custom_function title: EvaluationTaskType TaskDryRunRowResult: properties: row_index: type: integer title: Row Index success: type: boolean title: Success result: title: Result error: title: Error type: string type: object required: - row_index - success title: TaskDryRunRowResult ValidationError: properties: loc: items: anyOf: - type: string - type: integer type: array title: Location msg: type: string title: Message type: title: Error Type type: string input: title: Input ctx: type: object title: Context additionalProperties: true type: object required: - loc - msg - type title: ValidationError securitySchemes: APIKeyHeader: type: apiKey in: header name: x-api-key ````