> ## Documentation Index > Fetch the complete documentation index at: https://impossibl.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Evaluate state against typed questions (TypeSafe System One) > Mirrors TypeSafe AI's native `POST /v1/systemone` exactly, so the official TypeSafe SDKs work by pointing `TYPESAFE_BASE_URL` at this API. Send a `state` plus a map of typed `questions` (noul, choice, score) and receive one typed `answer` per question with probabilities and confidence. Requires a model whose `output_modality` is `evaluation` (typesafe-ai/jev); text models return 400. Billed on `usage.input_tokens` only; output tokens are reported but free. State and questions share a budget of roughly 32,000 tokens. ## OpenAPI ````yaml /openapi.yaml post /v1/systemone openapi: 3.1.0 info: title: Impossibl AI API version: 0.0.1 description: > The Impossibl AI API is one API for all AI providers, OpenAI-compatible across OpenAI, Anthropic, Google, xAI, and more (`GET /v1/models` lists the full catalog), billed from a prepaid credit balance. Usage is billed at the model rates published by GET /v1/models with no usage markup. Prepaid credit purchases charge a separate fixed 5% platform fee before tax. **Get started** Create a workspace key at https://impossibl.com/dashboard, then call a model with `Authorization: Bearer ` and a full model ID from `GET /v1/models`. The walkthrough is at https://impossibl.com/docs/quickstart. Agents can create a funded account and initial key with `POST /v1/accounts`. The current API continues to use `/v1`; there is no `/v2` base URL. Conversation history is managed by your application. Provider-specific SDK endpoints and fields outside this specification are not guaranteed compatible. servers: - url: https://api.impossibl.com description: Production - url: http://localhost:8787 description: Local dev security: - BearerKey: [] paths: /v1/systemone: post: summary: Evaluate state against typed questions (TypeSafe System One) description: >- Mirrors TypeSafe AI's native `POST /v1/systemone` exactly, so the official TypeSafe SDKs work by pointing `TYPESAFE_BASE_URL` at this API. Send a `state` plus a map of typed `questions` (noul, choice, score) and receive one typed `answer` per question with probabilities and confidence. Requires a model whose `output_modality` is `evaluation` (typesafe-ai/jev); text models return 400. Billed on `usage.input_tokens` only; output tokens are reported but free. State and questions share a budget of roughly 32,000 tokens. operationId: evaluateSystemOne requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/SystemOneRequest' responses: '200': description: >- One answer per question, keyed by the ids you chose, plus the concrete model version and token usage. content: application/json: schema: $ref: '#/components/schemas/SystemOneResponse' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '402': $ref: '#/components/responses/InsufficientCredits' '404': $ref: '#/components/responses/UnknownModel' '502': $ref: '#/components/responses/UpstreamError' '503': $ref: '#/components/responses/ProviderNotConfigured' components: schemas: SystemOneRequest: type: object required: - model - state - questions properties: model: type: string example: typesafe-ai/jev state: description: >- The content to evaluate — a plain string, or structured data such as a record or chat log. oneOf: - type: string - type: object additionalProperties: true - type: array items: {} questions: type: object minProperties: 1 description: Question ids you choose; answers come back under the same ids. additionalProperties: $ref: '#/components/schemas/SystemOneQuestion' SystemOneResponse: type: object required: - model - answers - usage properties: model: type: string example: jev-1.13.0 description: The concrete model version that answered. answers: type: object additionalProperties: $ref: '#/components/schemas/SystemOneAnswer' usage: type: object required: - input_tokens - output_tokens properties: input_tokens: type: integer minimum: 0 description: The billed count. output_tokens: type: integer minimum: 0 description: Reported by TypeSafe; not billed. request_id: type: string SystemOneQuestion: type: object required: - type - instructions description: >- A typed question. `noul` is yes/no (criteria optional, `{true, false}` descriptions); `choice` picks one option (criteria required, option -> description or null); `score` rates along an ordered rubric (criteria required, array of at least 2 levels, low to high). properties: type: type: string enum: - noul - choice - score instructions: $ref: '#/components/schemas/SystemOneEntry' criteria: description: Shape depends on `type` — see the description above. oneOf: - type: object additionalProperties: $ref: '#/components/schemas/SystemOneEntry' - type: array minItems: 2 items: $ref: '#/components/schemas/SystemOneEntry' SystemOneAnswer: type: object required: - type description: >- Matches its question's `type`. `noul` carries `noul` (0..1, probability of yes) and no confidence. `choice` carries `choice`, `confidence` and `probabilities`. `score` carries `score`, `confidence`, `legend` (level index -> description) and `probabilities`. properties: type: type: string enum: - noul - choice - score noul: type: number minimum: 0 maximum: 1 choice: type: string score: type: number confidence: type: number minimum: 0 maximum: 1 legend: type: object additionalProperties: type: string probabilities: type: object additionalProperties: type: number Error: type: object properties: error: type: object properties: message: type: string type: type: string description: >- Common types include authentication_error, invalid_request_error, insufficient_quota, billing_required, permission_error, upstream_error, and provider_not_configured. SystemOneEntry: description: >- Free-form content the model reads. A string, or JSON structure (object/array) when the content is already structured. oneOf: - type: string - type: object additionalProperties: true - type: array items: {} - type: 'null' responses: BadRequest: description: Malformed request (bad JSON, or missing required fields). content: application/json: schema: $ref: '#/components/schemas/Error' example: error: message: '`model` and `messages` are required' type: invalid_request_error Unauthorized: description: Missing or invalid API key. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: message: Invalid API key type: authentication_error InsufficientCredits: description: >- Available credits or postpaid headroom cannot cover the request's balance check, which can include estimated input cost. Top up or reduce the request size. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: message: Insufficient credits. Top up to continue. type: insufficient_quota UnknownModel: description: The requested `model` id is not in the registry (see GET /v1/models). content: application/json: schema: $ref: '#/components/schemas/Error' example: error: message: 'Unknown model: foo/bar' type: invalid_request_error UpstreamError: description: The upstream provider returned an error. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: message: 'permission-denied: ...' type: upstream_error ProviderNotConfigured: description: The provider for this model has no API key configured on the gateway. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: message: 'Provider not configured: missing OPENAI_API_KEY' type: provider_not_configured securitySchemes: BearerKey: type: http scheme: bearer description: Gateway API key (`imp-rt-...`) from POST /v1/accounts or /v1/keys. ````