> ## Documentation Index > Fetch the complete documentation index at: https://docs.opper.ai/llms.txt > Use this file to discover all available pages before exploring further. # System One evaluation > TypeSafe-compatible synchronous evaluation. Send `model`, `state` and named typed `questions` (`noul`, `choice`, `score`). Native model names such as `jev-latest` resolve to the TypeSafe catalog endpoint; fully-qualified `typesafe/...` IDs pin that endpoint. Returns TypeSafe's native `model`, `answers` and token `usage`, preserving probabilities, confidence and score legends. Uses a project-scoped Opper API key, Comply policies and provider entitlements. Cost and generation ID are returned in headers. Streaming, chat generation and tool calling are unsupported. See the [classification and scoring guide](/build/gateway/evaluations) for working examples, model discovery, and usage and billing behavior. ## OpenAPI ````yaml post /v3/compat/v1/systemone openapi: 3.1.0 info: description: Schema-driven generative API that orchestrates LLM-powered workflows. title: Task API version: 3.0.0 servers: - description: Production url: https://api.opper.ai - description: Local development url: http://localhost:8080 security: - BearerAuth: [] tags: - description: Schema-driven function management and execution name: Functions - description: OpenAI-compatible chat completions name: Chat - description: OpenAI Responses API compatible endpoint name: Responses - description: Google-compatible interactions endpoint name: Interactions - description: Model registry and capabilities name: Models - description: Synchronous image generation name: Images - description: Text-to-speech and speech-to-text name: Audio - description: Asynchronous video generation name: Videos - description: Reusable file storage for media inputs and generated outputs name: Files - description: Async generation status and downloads name: Artifacts - description: OpenAI-compatible embeddings name: Embeddings - description: Recorded HTTP request/response generations name: Generations - description: System health and status name: System - description: Roundtable endpoint — fan out a query to multiple LLMs and combine results name: Roundtable - description: Web search, fetch, and other utility tools name: Tools - description: Caller identity, credits, and usage name: Account - description: >- Programmatic project and API-key management. Authenticates with an `op-mak-…` management token; available on the control_plane and enterprise plans. name: Management paths: /v3/compat/v1/systemone: post: tags: - Compatibility summary: System One evaluation API description: >- TypeSafe-compatible synchronous evaluation. Send `model`, `state` and named typed `questions` (`noul`, `choice`, `score`). Native model names such as `jev-latest` resolve to the TypeSafe catalog endpoint; fully-qualified `typesafe/...` IDs pin that endpoint. Returns TypeSafe's native `model`, `answers` and token `usage`, preserving probabilities, confidence and score legends. Uses a project-scoped Opper API key, Comply policies and provider entitlements. Cost and generation ID are returned in headers. Streaming, chat generation and tool calling are unsupported. operationId: evaluateSystemOne parameters: - description: >- Function name for tracing and project-level guardrail function-scope filtering. in: header name: X-Opper-Name schema: type: string - description: Parent span ID for distributed tracing context. in: header name: X-Opper-Parent-Span-Id schema: format: uuid type: string - description: >- Comma-separated `key:value` usage-attribution tags (e.g. `tenant:acme,project:demo`, max 8). Recorded on the generation's billing/metrics rows; group spend by any key via GET /v2/analytics/usage?group_by=. Header-borne twin of the /v3/session URL prefix tags (which win per key when both are present); `opper.`-prefixed keys and `session_id` are reserved. Malformed values return 400. in: header name: X-Opper-Tags schema: type: string requestBody: content: application/json: schema: $ref: '#/components/schemas/EvaluationRequest' required: true responses: '200': content: application/json: schema: $ref: '#/components/schemas/EvaluationResponse' description: Successful response headers: X-Generation-Cost: description: Execution cost in USD, matching X-Opper-Cost. schema: format: double type: number X-Generation-Id: description: Opper generation ID for this evaluation. schema: type: string X-Opper-Cost: description: Execution cost of the request as a floating-point number. schema: format: double type: number X-Opper-Trace-Id: description: Trace UUID for this evaluation. schema: format: uuid type: string '400': content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' description: Bad request '401': description: Unauthorized - missing or invalid API key '500': content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' description: Internal server error '529': description: TypeSafe is temporarily overloaded components: schemas: EvaluationRequest: additionalProperties: false properties: model: minLength: 1 type: string questions: additionalProperties: $ref: '#/components/schemas/EvaluationQuestion' minProperties: 1 type: object state: oneOf: - type: string - type: object - items: {} type: array required: - model - state - questions type: object EvaluationResponse: properties: answers: additionalProperties: $ref: '#/components/schemas/EvaluationAnswer' type: object model: type: string usage: $ref: '#/components/schemas/EvaluationUsage' required: - model - answers - usage type: object ErrorResponse: properties: error: properties: code: type: string details: description: Any value message: type: string required: - code - message type: object meta: type: object required: - error type: object EvaluationQuestion: oneOf: - additionalProperties: false properties: criteria: additionalProperties: false properties: 'false': oneOf: - type: string - type: object - items: {} type: array 'true': oneOf: - type: string - type: object - items: {} type: array type: object instructions: oneOf: - type: string - type: object - items: {} type: array type: enum: - noul type: string required: - type - instructions type: object - additionalProperties: false properties: criteria: additionalProperties: oneOf: - type: - string - 'null' - type: object - items: {} type: array maxProperties: 255 minProperties: 1 type: object instructions: oneOf: - type: string - type: object - items: {} type: array type: enum: - choice type: string required: - type - instructions - criteria type: object - additionalProperties: false properties: criteria: items: oneOf: - type: string - type: object - items: {} type: array maxItems: 10 minItems: 2 type: array instructions: oneOf: - type: string - type: object - items: {} type: array type: enum: - score type: string required: - type - instructions - criteria type: object EvaluationAnswer: oneOf: - additionalProperties: true properties: noul: maximum: 1 minimum: 0 type: number type: enum: - noul type: string required: - type - noul type: object - additionalProperties: true properties: choice: type: string confidence: maximum: 1 minimum: 0 type: number probabilities: additionalProperties: maximum: 1 minimum: 0 type: number type: object type: enum: - choice type: string required: - type - choice - confidence - probabilities type: object - additionalProperties: true properties: confidence: maximum: 1 minimum: 0 type: number legend: additionalProperties: oneOf: - type: string - type: object - items: {} type: array type: object probabilities: additionalProperties: maximum: 1 minimum: 0 type: number type: object score: maximum: 9 minimum: 0 type: number type: enum: - score type: string required: - type - score - confidence - probabilities - legend type: object EvaluationUsage: properties: input_tokens: minimum: 0 type: integer output_tokens: minimum: 0 type: integer required: - input_tokens - output_tokens type: object securitySchemes: BearerAuth: bearerFormat: API Key description: API key authentication. Pass your API key as a Bearer token. scheme: bearer type: http ````