> ## 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: scores-v3 description: Unified CRUD for scores and annotations - 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 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 nullable: true additionalProperties: anyOf: - type: string - type: array items: type: string description: >- Mapping of input field names to verbatim span attribute keys (framework-specific). Mutually exclusive with `mapped_semantic_names` — provide exactly one. mapped_semantic_names: type: object nullable: true additionalProperties: anyOf: - type: string - type: array items: type: string description: >- Mapping of input field names to semantic concept names (framework-agnostic). Same structure as `mapped_input_keys` but values are semantic concepts instead of literal attribute keys. The enrichment worker resolves each concept to all mapped attribute keys at evaluation time via the semantic mapping cache. Valid concepts: `input`, `output`, `system_instructions`, `retrieval_context`, `tool_input`, `tool_output`. Mutually exclusive with `mapped_input_keys` — provide exactly one. 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 nullable: true additionalProperties: anyOf: - type: string - type: array items: type: string description: >- Mapping of input field names to verbatim span attribute keys. Null when `mapped_semantic_names` is set. mapped_semantic_names: type: object nullable: true additionalProperties: anyOf: - type: string - type: array items: type: string description: >- Mapping of input field names to semantic concept names. Null when `mapped_input_keys` is set. 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 ````