> ## 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. # Get a decision > Reads only. The decision's version count and its newest version (the most recently registered, the highest number). It belongs to the whole organization, so test and production keys read the same one. 404 DECISION_UNKNOWN when no version was ever registered under the id. ## OpenAPI ````yaml /openapi.json get /v1/decisions/{decision_id} openapi: 3.1.0 info: title: Moonbounce Decisions API version: 0.0.0 description: >- Moonbounce decisions: evaluate an item's state against a decision structure (System One questions, attributes you supply and aggregations over both), record feedback and import labeled examples, review a ranked queue, and improve the structure 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/validate`. 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/validate` and `POST /v1/review/items/fill`, whose retry is another fill within the day's budget). 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/decisions/{decision_id}: get: tags: - decisions summary: Get a decision description: >- Reads only. The decision's version count and its newest version (the most recently registered, the highest number). It belongs to the whole organization, so test and production keys read the same one. 404 DECISION_UNKNOWN when no version was ever registered under the id. operationId: getDecision parameters: - schema: $ref: '#/components/schemas/DecisionId' required: true description: >- A name you choose for this decision, such as `refund-exception`: a lowercase letter, then up to 127 of `a-z 0-9 _ . -`. Unique in your organization and shared by its test and production keys. The first registration or evaluation under a new one creates the decision. name: decision_id in: path responses: '200': description: The decision content: application/json: examples: refund_exception: summary: The refund decision after its second version value: decision_id: refund-exception created_at: '2026-11-06T09:00:00.000Z' version_count: 2 newest_version: structure_hash: >- sha256:08bdcc48471e664be5515a00666df06323ddd306ed41f7c7315dfc85d98e628f number: 2 created_at: '2026-11-06T15:30:00.000Z' schema: $ref: '#/components/schemas/Decision' '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' '404': description: Not found, or not in this key's organization and environment 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) 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: $ref: '#/components/schemas/ErrorBody' security: - bearerAuth: - decisions:evaluate - bearerAuth: - decisions:develop components: schemas: DecisionId: type: string pattern: ^[a-z][a-z0-9_.-]{0,127}$ description: >- A name you choose for this decision, such as `refund-exception`: a lowercase letter, then up to 127 of `a-z 0-9 _ . -`. Unique in your organization and shared by its test and production keys. The first registration or evaluation under a new one creates the decision. Decision: type: object properties: decision_id: $ref: '#/components/schemas/DecisionIdOutput' created_at: type: string format: date-time description: When the decision's first version was registered. version_count: type: integer minimum: 1 description: How many versions are registered under the decision. newest_version: type: object properties: structure_hash: $ref: '#/components/schemas/StructureHashOutput' number: $ref: '#/components/schemas/VersionNumber' created_at: type: string format: date-time description: When the version was first registered. required: - structure_hash - number - created_at additionalProperties: true description: The most recently registered version (the highest number). x-moonbounce-sdk-known-fields: true required: - decision_id - created_at - version_count - newest_version additionalProperties: true description: >- A decision and its registered versions. It belongs to the whole organization: test and production keys see the same one. x-moonbounce-sdk-known-fields: true 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 (`attribute_values.region`, `claims.1.value`). details: type: object properties: issues: type: array items: $ref: '#/components/schemas/ErrorIssue' additionalProperties: {} required: - type - message additionalProperties: true x-moonbounce-sdk-known-fields: true required: - error additionalProperties: true x-moonbounce-sdk-known-fields: true DecisionIdOutput: type: string pattern: ^[a-z][a-z0-9_.-]{0,127}$ description: >- A name you choose for this decision, such as `refund-exception`: a lowercase letter, then up to 127 of `a-z 0-9 _ . -`. Unique in your organization and shared by its test and production keys. The first registration or evaluation under a new one creates the decision. StructureHashOutput: type: string pattern: ^sha256:[0-9a-f]{64}$ VersionNumber: type: integer minimum: 1 description: >- The version's number under its decision: 1 for the first structure registered, then 2, 3... in the order the organization registered them. For people; the hash is the version's identity. ErrorType: type: string enum: - invalid_request - authentication - permission_denied - not_found - conflict - rate_limited - engine_failed - unavailable - internal ErrorIssue: type: object properties: param: type: string code: type: string pattern: ^[A-Z][A-Z0-9_]+$ description: >- Stable, extensible issue code; unknown codes still have a parameter and human-readable message. message: type: string required: - param - code - message additionalProperties: true x-moonbounce-sdk-known-fields: true 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.