> ## Documentation Index > Fetch the complete documentation index at: https://docs.mixpeek.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Get Stats > Get aggregate statistics for a retriever's learned fusion system. ## OpenAPI ````yaml get /v1/retrievers/{retriever_id}/learned-fusion/stats openapi: 3.1.0 info: title: Mixpeek API description: >- This is the Mixpeek API, providing access to various endpoints for data processing and retrieval. termsOfService: https://mixpeek.com/terms contact: name: Mixpeek Support url: https://mixpeek.com/contact email: info@mixpeek.com version: '0.82' servers: - url: https://api.mixpeek.com description: Production security: - BearerAuth: [] paths: /v1/retrievers/{retriever_id}/learned-fusion/stats: get: tags: - Retriever Learned Fusion summary: Get Stats description: Get aggregate statistics for a retriever's learned fusion system. operationId: get_stats_v1_retrievers__retriever_id__learned_fusion_stats_get parameters: - name: retriever_id in: path required: true schema: type: string title: Retriever Id responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/LearnedFusionStatsResponse' '400': description: Bad Request content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '401': description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '403': description: Forbidden content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '404': description: Not Found content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' '500': description: Internal Server Error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' security: - BearerAuth: [] NamespaceHeader: [] components: schemas: LearnedFusionStatsResponse: properties: total_learners: type: integer title: Total Learners description: Total number of unique users with learned weights. active_learners: type: integer title: Active Learners description: >- Unique users the system is actively learning for (alias of total_learners — backs the Studio Overview 'Active Learners' card). default: 0 avg_interactions_per_user: type: number title: Avg Interactions Per User description: Average number of interactions per user. weight_spread: type: number title: Weight Spread description: Maximum divergence of any feature weight from uniform. context_level_distribution: additionalProperties: type: integer type: object title: Context Level Distribution description: Count of users at each context level (personal/demographic/global). context_hit_rate: type: number title: Context Hit Rate description: >- Fraction of learners that have reached a personalized (non-global) context — enough interactions for personal weights (0-1). default: 0 enabled: type: boolean title: Enabled description: Whether learned fusion is currently enabled for this retriever. rollout_pct: type: number title: Rollout Pct description: >- Effective percentage of traffic receiving learned fusion weights (a live override takes precedence over the configured value). rollout_override: type: boolean title: Rollout Override description: Whether a live rollout override is active (vs the config value). default: false config_rollout_pct: type: number title: Config Rollout Pct description: The retriever's configured rollout_pct (ignoring any live override). default: 100 shadow_mode: type: boolean title: Shadow Mode description: Whether learned fusion is running in shadow mode (logging only). source: anyOf: - type: string - type: 'null' title: Source description: >- Which store served the weights: 'signals' (the namespace's _signals collection) or 'clickhouse' (analytics fallback). warning: anyOf: - type: string - type: 'null' title: Warning description: >- Set when the response contains fallback defaults due to an internal error. hint: anyOf: - type: string - type: 'null' title: Hint description: >- Set when learned fusion is NOT configured for this retriever — the payload is a well-formed empty state and this explains how to enable learning. type: object required: - total_learners - avg_interactions_per_user - weight_spread - context_level_distribution - enabled - rollout_pct - shadow_mode title: LearnedFusionStatsResponse description: Aggregate statistics for a retriever's learned fusion system. ErrorResponse: properties: success: type: boolean title: Success description: Always false for error responses default: false status: type: integer title: Status description: HTTP status code for this error error: $ref: '#/components/schemas/ErrorDetail' description: Error details payload type: object required: - status - error title: ErrorResponse description: Error response model. examples: - error: details: id: ns_123 resource: namespace message: Namespace not found type: NotFoundError status: 404 success: false HTTPValidationError: properties: detail: items: $ref: '#/components/schemas/ValidationError' type: array title: Detail type: object title: HTTPValidationError ErrorDetail: properties: message: type: string title: Message description: Human-readable error message type: type: string title: Type description: Stable error type identifier (machine-readable) code: anyOf: - type: string - type: 'null' title: Code description: >- Fine-grained error code for programmatic handling (e.g., namespace_name_taken, feature_extractor_not_found). Present only when consumers may need to branch on a specific error condition. details: anyOf: - additionalProperties: true type: object - type: 'null' title: Details description: >- Optional structured details to help debugging (validation errors, IDs, etc.) type: object required: - message - type title: ErrorDetail description: Error detail model. ValidationError: properties: loc: items: anyOf: - type: string - type: integer type: array title: Location msg: type: string title: Message type: type: string title: Error Type input: title: Input ctx: type: object title: Context type: object required: - loc - msg - type title: ValidationError securitySchemes: BearerAuth: type: http scheme: bearer description: >- Mixpeek API key, sent as `Authorization: Bearer mxp_sk_...`. Create one in Studio under Settings → API Keys, or with an admin key via `POST /v1/organizations/users/{user_email}/api-keys`. A missing header returns 403; an invalid or revoked key returns 401. NamespaceHeader: type: apiKey in: header name: X-Namespace description: >- Namespace id (`ns_...`), not the namespace name. This scopes the request rather than authenticating it, and it is required on every operation marked `x-mixpeek-namespace-scoped`. ````