> ## Documentation Index > Fetch the complete documentation index at: https://docs.fiddler.ai/llms.txt > Use this file to discover all available pages before exploring further. # Create New Evaluator Rule > Create a new Evaluator Rule ## OpenAPI ````yaml POST /v3/evaluator-rules openapi: 3.0.3 info: title: Fiddler API - 2.0 description: APIs to interact with Fiddler termsOfService: https://fiddler.ai/about/terms contact: email: support@fiddler.ai license: name: Proprietary url: '2.0' version: '2.0' servers: [] security: - BearerAuth: [] tags: - name: access-key description: CRUD operations for API keys - name: span-v3 - name: aggregation-invalidation-request-v3 description: Endpoints related to retrieving aggregation invalidation requests - name: alert-rules-v3 description: CRUD for Alert Rules, Summary, and Stats APIs - name: application-v3 - name: attribute-v3 - name: auth description: Authentication strategies and login flows - name: baseline-v3 description: CRUD for baseline - name: catalog-v3 description: >- Entity catalog provides paginated, searchable discovery of entity names (attribute keys, agent names, span types, span names) and their distinct values. Powered by ClickHouse materialized views — no worker or PostgreSQL dependency. - name: chart-annotation-v3 description: Endpoints related to retrieving chart annotations - name: chart-v3 description: CRUD for chart - name: queries-v3 description: v3 queries API - name: configuration-v3 description: CRUD for configurations - name: custom-metrics-v3 - name: dimensionality-reduction-v3 - name: environment-v3 description: Endpoints related to environment management - name: evals - name: datasets - name: evaluation-v3 - name: evaluator-v3 - name: rule-evaluators-v3 - name: experiment-v3 - name: explainability-v3 - name: llm_rca-v3 - name: file-upload description: Endpoints related to file uploading. - name: fql-expressions-v3 description: > Endpoints for listing FQL (Fiddler Query Language) functions available for GenAI custom metrics. Used by the frontend for autocomplete and signature hints in the FQL editor. - name: genai-alert-rules-v3 description: CRUD API for GenAI Alert Rules - name: genai-custom-metrics-v3 description: API for GenAI Custom Metrics - name: genai-metrics-v3 description: >- Endpoints for pre-aggregated GenAI metrics. All metric data is pre-aggregated by an hourly ClickHouse refreshable materialized view; no real-time aggregation is performed at request time. - name: guardrails-api description: Endpoints related to retrieving Guardrails specific data - name: ingestion-v3 - name: intercom-api description: Endpoints related to intercom APIs - name: jobs-v3 - name: llm-gateway-v3 - name: auth-login - name: auth-logout - name: metrics-v3 description: Metrics endpoints - name: model-v3 - name: dashboard-v3 - name: model-deployment-v3 - name: monitoring-summary-v3 - name: histograms-v3 - name: organization-roles-v3 description: Update user org role - name: organization-settings-v3 description: Update organization settings such as timezone, email configuration, etc. - name: pagerduty-api description: CRUD for Pagerduty services. - name: project-v3 - name: project-roles-v3 description: Project role assignment management - name: searchable-text-key-v3 description: >- Manage the global searchable text keys table that controls which OTel attribute keys are routed to the full-text-searchable `ValueContent` column in the unified attributes table. Changes propagate to the backing ClickHouse dictionary within 1-2 minutes and affect all tenants. - name: segments-v3 - name: semantic-mapping-v3 description: >- Manage the global semantic name mappings table that maps raw OTel attribute keys to canonical semantic concepts. Changes propagate to the backing ClickHouse dictionary within 1-2 minutes and affect all tenants. - name: server-info-v3 description: Endpoints related to retrieving server information - name: sessions-v3 description: v3 session APIs - name: team-roles-v3 - name: team-v3 - name: traces-v3 description: v3 trace api for monitoring - name: fetch-sessions-v3 description: v3 fetch sessions api for monitoring - name: user-access-key description: > CRUD operations for user API keys. All endpoints are user-scoped — each user can only operate on their own API keys. No one including Org admins have access to other users' API keys. - name: users-v3 - name: version-compatibility-v3 - name: webhooks externalDocs: url: https://docs.fiddler.ai description: Find out more about Fiddler paths: /v3/evaluator-rules: post: tags: - evaluator-rules-v3 summary: Create New Evaluator Rule description: Create a new Evaluator Rule operationId: createEvaluatorRuleV3 requestBody: content: application/json: schema: $ref: '#/components/schemas/RuleEvaluatorRequest' responses: '200': description: Details of the created evaluator rule content: application/json: schema: allOf: - $ref: '#/components/schemas/ApiResponse' - type: object properties: data: $ref: '#/components/schemas/RuleEvaluator' '400': $ref: '#/components/responses/400' '429': $ref: '#/components/responses/429' '500': $ref: '#/components/responses/500' components: schemas: RuleEvaluatorRequest: type: object title: Rule Evaluator Request description: Request body for creating a Rule evaluator with filters required: - name - application_id - evaluator_id - mapped_input_keys properties: name: type: string description: Name of the Rule evaluator application_id: type: string format: uuid description: Application UUID evaluator_id: type: string format: uuid description: UUID of the corresponding evaluator mapped_input_keys: type: object additionalProperties: anyOf: - type: string - type: array items: type: string description: Mapping of input key names to attribute paths filters: $ref: '#/components/schemas/EvaluatorRuleFilters' backfill: description: Whether to backfill already ingested spans type: boolean default: false sampling_rate: description: >- Fraction of matching spans on which this evaluator runs, in the half-open range (0.0, 1.0]. Defaults to 1.0 (every matching span). Traces are always persisted even when downsampling is enabled. To pause evaluation entirely, create the rule and then PATCH it with `enabled=false` — a small `sampling_rate` is not a pause mechanism (and `enabled` is not accepted on this create request). default: 1 allOf: - $ref: '#/components/schemas/SamplingRate' backfill_start_time: description: >- Starting point for backfill in case backfill is not required for the entire period type: string format: date-time nullable: true ApiResponse: type: object description: | Response object for standard API responses. properties: api_version: type: string default: '3.0' enum: - '2.0' - '3.0' description: | API version. kind: type: string default: NORMAL enum: - NORMAL description: | Type of response, indicating a normal response. RuleEvaluator: type: object description: Rule Evaluator required: - id - name - evaluator_id - evaluator_name - evaluator_type - evaluator_type_display_name - mapped_input_keys - enabled - filters - outputs - backfill - created_at - updated_at allOf: - $ref: '#/components/schemas/CreateUpdateTimestamp' - type: object properties: id: description: Unique identifier of the Rule evaluator type: string format: uuid name: type: string description: Name of the Rule evaluator evaluator_id: type: string format: uuid description: UUID of the corresponding evaluator evaluator_name: type: string description: Name of the corresponding evaluator evaluator_type: $ref: '#/components/schemas/EnrichmentName' evaluator_type_display_name: type: string description: Human-readable display name for the evaluator type mapped_input_keys: type: object additionalProperties: anyOf: - type: string - type: array items: type: string description: Mapping of input key names to attribute paths filters: $ref: '#/components/schemas/EvaluatorRuleFilters' outputs: $ref: '#/components/schemas/RuleEvaluatorOutputList' enabled: type: boolean description: Indicates if the evaluator is enabled or disabled sampling_rate: description: >- Fraction of matching spans on which this evaluator runs, in (0.0, 1.0]. Always present; defaults to 1.0 for rules created before this field existed. allOf: - $ref: '#/components/schemas/SamplingRate' application: $ref: '#/components/schemas/ApplicationCompact' backfill: $ref: '#/components/schemas/EvaluatorRuleBackfill' EvaluatorRuleFilters: type: object description: Filters for applying Rule evaluator required: - condition - rules properties: condition: $ref: '#/components/schemas/QueryConditionType' rules: type: array items: anyOf: - $ref: '#/components/schemas/QueryConditionType' - $ref: '#/components/schemas/QueryRule' SamplingRate: type: number format: float description: >- Shared numeric constraint for an evaluator rule's `sampling_rate`: a fraction in the half-open range (0.0, 1.0]. 0.0 is rejected — to pause evaluation entirely, PATCH the rule with `enabled=false` instead. Referenced via `allOf` so each usage can add its own description/default. maximum: 1 minimum: 0 exclusiveMinimum: true CreateUpdateTimestamp: type: object required: - created_at - updated_at properties: created_at: type: string format: date-time readOnly: true description: | Date and time when the object was created. updated_at: type: string format: date-time readOnly: true description: | Date and time when the object was last updated. EnrichmentName: type: string description: Type of enrichment enum: - topic_classification - embedding - token_count - answer_relevance - coherence - conciseness - rag_faithfulness - pii_detection - ftl_prompt_safety - secret_detection - sentiment_analysis - ftl_response_faithfulness - llm_as_a_judge RuleEvaluatorOutputList: type: array description: List of outputs for the rule evaluator items: $ref: '#/components/schemas/RuleEvaluatorOutput' ApplicationCompact: type: object title: ApplicationCompact description: > Compact version of an application which can be included in the response of relevant APIs. required: - id - name properties: id: type: string format: uuid description: | Unique identifier of the application. name: type: string description: | Name of the application. EvaluatorRuleBackfill: type: object description: Details of the evaluator rule backfill required: - id - status - backfill_start_time properties: id: type: string format: uuid backfill_start_time: type: string format: date-time nullable: true status: type: string enum: - PENDING - IN_PROGRESS - COMPLETED - FAILED - PARTIALLY_COMPLETED ErrorResponse: type: object description: | Response object for errors returned by the API. properties: api_version: type: string default: '3.0' enum: - '2.0' - '3.0' description: | API version of the response. kind: type: string default: ERROR enum: - ERROR description: | Type of response, usually indicating an error. error: type: object properties: code: type: integer format: int32 description: > Represents the code for this error, typically an HTTP response code. default: 400 enum: - 400 - 403 - 404 - 500 message: type: string description: > A human-readable message providing more details about the error. If there are multiple errors, it will be the message for the first error. example: Resource Not Found errors: type: array description: > Container for additional information regarding the error, especially for multiple errors. items: type: object properties: reason: type: string description: > Unique identifier for this error, different from the error code. example: ResourceNotFoundException message: type: string description: > A human-readable message providing more details about the error. If there is only one error, this field will match error.message. example: Resource Not Found help: type: string description: > Link to support or documentation providing more information on the error. QueryConditionType: type: string description: Condition type to apply for filters enum: - AND - OR QueryRule: type: object description: Rule to apply for filters required: - field - operator - value properties: field: type: string description: Name of the field to apply the filter on operator: $ref: '#/components/schemas/OperatorType' value: description: value of the filter anyOf: - type: string - type: number - type: boolean - type: array items: type: string RuleEvaluatorOutput: type: object description: Output name and type properties: name: type: string description: output name type: description: output type type: string enum: - boolean - string - number - integer possible_values: description: List of possible values for categorical outputs type: array items: type: string OperatorType: type: string description: Type of operator enum: - EQUAL - NOT_EQUAL - IN - NOT_IN - LESS - LESS_OR_EQUAL - GREATER - GREATER_OR_EQUAL - BETWEEN responses: '400': description: Bad Request content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '429': description: Rate limit exceeded content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' headers: Retry-After: schema: type: integer description: Seconds to wait before retrying X-RateLimit-Limit: schema: type: string description: Rate limit policy X-RateLimit-Remaining: schema: type: integer description: Remaining requests in current window X-RateLimit-Reset: schema: type: integer description: Unix timestamp when the rate limit resets '500': description: Internal Server Error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' securitySchemes: BearerAuth: type: http scheme: bearer ````