> ## Documentation Index > Fetch the complete documentation index at: https://docs.moonbounce.ai/llms.txt > Use this file to discover all available pages before exploring further. # List the engines a decision can run on > The engines this deployment offers, their models and what each model reports: the resolved model, whether it is pinned, the node types and content it reads, and its list price. Choose one for a decision with `POST /v1/decisions/{decision_id}/binding/revisions`. ## OpenAPI ````yaml /openapi.json get /v1/engines openapi: 3.1.0 info: title: Moonbounce Decisions API version: 0.0.0 description: >- Moonbounce decisions: evaluate items against a decision spec (features combined by aggregators), record feedback and seed examples, review a ranked queue, and improve the spec through suggestions that ship as code diffs, each with a preview (backtest) and an evidence label. **Authentication.** Send an API key as `Authorization: Bearer ` on every operation except `GET /health` and `POST /v1/specs/hash`. Call the API from a server, never a browser: a key must not reach one, and the API sends no CORS headers. A key belongs to one organization and one environment: production, or test for a key with the `env:test` permission. Test traffic never counts as production traffic. **Requests.** JSON bodies (`Content-Type: application/json`) of at most 1 MB, parsed strictly: duplicate keys, lone surrogates, integers outside ±(2^53 - 1), `__proto__` keys, U+0000 and nesting deeper than 64 are a 400. **Retries.** Send an `Idempotency-Key` on every POST under /v1 that takes one (all but `POST /v1/specs/hash`). Keep it for the request's retries. The same key with the same request returns the first stored result, marked `Idempotent-Replayed: true`, for 24 hours (410 if that result was since deleted); with another request it is 422 IDEMPOTENCY_KEY_REUSED. Keys are scoped to the organization and environment across every operation, so use a fresh key per request. A request that failed before its result was stored runs again when retried. 429 and 503 under /v1 may carry `Retry-After` (seconds); a daily QUOTA_EXCEEDED cap instead names its reset time. **Errors.** Every error under /v1 is `{"error": {"type", "message", "reason"?, "param"?, "details"?}}` (ErrorBody); `GET /health` answers its own shape. Every response carries a `Request-Id` header. Rate limits apply per key, and per client IP for requests without a valid key; a 429 RATE_LIMITED carries `Retry-After`. servers: - url: https://api.moonbounce.ai description: Production security: [] paths: /v1/engines: get: tags: - engines summary: List the engines a decision can run on description: >- The engines this deployment offers, their models and what each model reports: the resolved model, whether it is pinned, the node types and content it reads, and its list price. Choose one for a decision with `POST /v1/decisions/{decision_id}/binding/revisions`. operationId: listEngines responses: '200': description: The offered engines content: application/json: schema: $ref: '#/components/schemas/EngineList' '400': description: 'Invalid request: `param` names the field at fault when one applies' content: application/json: schema: $ref: '#/components/schemas/ErrorBody' '401': description: Missing or invalid API key (reason KEY_INVALID) content: application/json: schema: $ref: '#/components/schemas/ErrorBody' '403': description: The key may not do this content: application/json: schema: $ref: '#/components/schemas/ErrorBody' '429': description: >- RATE_LIMITED: retry after Retry-After seconds; QUOTA_EXCEEDED: details.reset_at gives the daily reset time (no Retry-After), or details.too_large asks for a smaller request headers: Retry-After: schema: type: string description: Seconds to wait before retrying, when waiting helps. required: false description: Seconds to wait before retrying, when waiting helps. content: application/json: schema: $ref: '#/components/schemas/ErrorBody' '503': description: >- Temporarily unavailable, with Retry-After (for example reason AUTH_UNAVAILABLE, ENGINE_UNAVAILABLE or STORE_UNAVAILABLE): retry with the same Idempotency-Key headers: Retry-After: schema: type: string description: Seconds to wait before retrying, when waiting helps. required: true description: Seconds to wait before retrying, when waiting helps. content: application/json: schema: $ref: '#/components/schemas/ErrorBody' security: - bearerAuth: [] components: schemas: EngineList: type: object properties: default: type: object properties: engine: type: string minLength: 1 maxLength: 64 description: >- An engine id from `GET /v1/engines`, e.g. `jev` or `clef`. Open: new engines are added without a contract change. example: clef model: type: string minLength: 1 maxLength: 128 description: >- A model id the engine lists in `GET /v1/engines`. `*-latest` and `*-preview` aliases are refused; whether an id fixes the model's behavior is its `pinned` flag. example: '@cf/cloudflare/clef' required: - engine - model description: >- What a decision's first structure registration binds it to in this deployment. Absent when that engine is not offered (its key or binding is missing): new decisions then cannot evaluate until it is fixed or they are moved. engines: type: array items: $ref: '#/components/schemas/Engine' required: - engines ErrorBody: type: object properties: error: type: object properties: type: $ref: '#/components/schemas/ErrorType' reason: type: string pattern: ^[A-Z][A-Z0-9_]+$ description: >- Set where a caller can act on it, one of the reasons in the ErrorReason schema. New reasons may be added: treat an unknown one by the status and `type`. message: type: string description: For people; don't parse it. param: type: string description: >- The request field at fault, as a dotted path (`subject.0.text`, `claims.1.value`). details: type: object additionalProperties: {} required: - type - message additionalProperties: false required: - error additionalProperties: false Engine: type: object properties: engine: type: string minLength: 1 maxLength: 64 description: >- An engine id from `GET /v1/engines`, e.g. `jev` or `clef`. Open: new engines are added without a contract change. example: clef adapter: type: string description: The adapter and its version; part of the engine profile. default_model: type: string minLength: 1 maxLength: 128 description: >- A model id the engine lists in `GET /v1/engines`. `*-latest` and `*-preview` aliases are refused; whether an id fixes the model's behavior is its `pinned` flag. example: '@cf/cloudflare/clef' models: type: array items: $ref: '#/components/schemas/EngineModel' required: - engine - adapter - default_model - models ErrorType: type: string enum: - invalid_request - authentication - permission_denied - not_found - conflict - rate_limited - engine_failed - unavailable - internal EngineModel: type: object properties: model: type: string minLength: 1 maxLength: 128 description: >- A model id the engine lists in `GET /v1/engines`. `*-latest` and `*-preview` aliases are refused; whether an id fixes the model's behavior is its `pinned` flag. example: '@cf/cloudflare/clef' resolved_model: type: string description: >- What evaluations report as the model that answered, and part of the engine profile weights are fit for. pinned: type: boolean description: >- Whether the id fixes the model's behavior. `false` means the provider can change what the id serves (an alias), so answers and fitted weights can drift without the profile changing. feature_types: type: array items: type: string description: Node types the engine answers, e.g. `boolean`. modalities: type: object additionalProperties: type: string enum: - ga - preview description: >- Content part types the engine reads. `preview` ones are not used by evaluate yet. pricing: type: object properties: input_per_mtok_usd: type: number minimum: 0 output_per_mtok_usd: type: number minimum: 0 source: type: string required: - source description: The list price the adapter bills usage at, and where it comes from. required: - model - resolved_model - pinned - feature_types - modalities securitySchemes: bearerAuth: type: http scheme: bearer description: >- An API key, sent as `Authorization: Bearer `. Each operation lists the scope its key needs: `decisions:evaluate` (evaluate and read evaluations), `decisions:feedback` (your app's feedback) or `decisions:develop` (everything else, including owner feedback and the review queue). An operation listing no scope takes any scoped key. A key with no scope, or without the operation's, gets 403 INSUFFICIENT_SCOPE. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.