> ## Documentation Index > Fetch the complete documentation index at: https://docs.trusys.ai/llms.txt > Use this file to discover all available pages before exploring further. # Configure guardrails > Enables or disables guardrails and sets input/output validators for an application. `input_validators` and `output_validators` are **arrays of objects**. Each entry requires: - `type` — validator id from `GET /guardrails/validators` - `on_fail` — action id from the catalog `actions` list (what Trusys does when the validator fails: `mask`, `encrypt`, `filter`, `fail`, `ignore`, or `fix` for PII only) - `config` — optional; structure depends on `type` (see catalog `validators[].config` for the template) Not every `on_fail` action applies to every validator — the catalog `actions[].validators` array lists compatible validator types. ## OpenAPI ````yaml /openapi.json put /applications/{applicationId}/guardrails openapi: 3.0.0 info: title: Trusys API version: 1.0.0 description: >- Programmatic access to Trusys for integrating AI quality monitoring, evaluation, and guardrails into your own systems — without using the Trusys UI. **Typical integration flow** 1. `POST /applications` — register your application and get an id. 2. `PUT /applications/{id}/monitoring` and/or `PUT /applications/{id}/guardrails` — configure which metrics, security plugins, and guardrails apply. 3. `POST /applications/{id}/evaluations` — submit prompt/response traces to be scored as your application runs. 4. `GET /applications/{id}/traces`, `GET /applications/{id}/evaluations`, and `POST /applications/{id}/widget-data` — pull results, trends, and dashboard-equivalent chart data back into your own tools. All requests require an `x-api-key` header (see Authentication). All timestamps are ISO 8601 UTC. Paginated endpoints default to 20 items per page (max 100). servers: - url: https://app.trusys.ai/api/external security: - ApiKeyAuth: [] paths: /applications/{applicationId}/guardrails: put: tags: - Guardrails summary: Configure guardrails description: >- Enables or disables guardrails and sets input/output validators for an application. `input_validators` and `output_validators` are **arrays of objects**. Each entry requires: - `type` — validator id from `GET /guardrails/validators` - `on_fail` — action id from the catalog `actions` list (what Trusys does when the validator fails: `mask`, `encrypt`, `filter`, `fail`, `ignore`, or `fix` for PII only) - `config` — optional; structure depends on `type` (see catalog `validators[].config` for the template) Not every `on_fail` action applies to every validator — the catalog `actions[].validators` array lists compatible validator types. operationId: updateGuardrailsConfig parameters: - $ref: '#/components/parameters/applicationId' requestBody: required: true description: Guardrails toggle and validator lists. content: application/json: schema: $ref: '#/components/schemas/PutGuardrailsRequest' example: enable_guard_rails: true input_validators: - type: prompt-injection on_fail: fail config: threshold: 0.8 output_validators: - type: pii on_fail: mask config: entities: - EMAIL_ADDRESS threshold: 0.5 responses: '200': description: Guardrails configuration saved. content: application/json: schema: $ref: '#/components/schemas/GuardrailsConfigResponse' '400': $ref: '#/components/responses/ValidationError' '401': $ref: '#/components/responses/Unauthorized' '404': $ref: '#/components/responses/NotFound' components: parameters: applicationId: name: applicationId in: path required: true schema: type: string format: uuid description: >- Unique identifier (UUID) of the application. Returned by `POST /applications`. schemas: PutGuardrailsRequest: type: object additionalProperties: false required: - enable_guard_rails properties: enable_guard_rails: type: boolean description: Master switch for guardrails on this application. input_validators: type: array description: >- Validators applied to user/model input. Each item is an object with `type`, `on_fail`, and optional `config`. items: $ref: '#/components/schemas/GuardrailValidatorEntry' output_validators: type: array description: >- Validators applied to model output. Each item is an object with `type`, `on_fail`, and optional `config`. items: $ref: '#/components/schemas/GuardrailValidatorEntry' GuardrailsConfigResponse: type: object properties: success: type: boolean data: $ref: '#/components/schemas/GuardrailsConfigData' GuardrailValidatorEntry: type: object additionalProperties: false description: >- Single guardrail validator configuration. Stored as an element in `input_validators` or `output_validators` arrays. required: - type - on_fail properties: type: type: string description: >- Validator id from `GET /guardrails/validators` (for example `pii`, `prompt-injection`, `regex`). on_fail: type: string description: >- Action id from catalog `actions` — enforced when this validator fails. Common values: `mask`, `encrypt`, `filter`, `fail`, `ignore`. `fix` is supported for `pii` only. config: description: >- Validator-specific settings. Shape depends on `type` — use the catalog `validators[].config` object as a template. May be an object (for example `{ "threshold": 0.8 }`) or an array (for example regex/blocklist pattern rows). example: type: prompt-injection on_fail: fail config: threshold: 0.8 GuardrailsConfigData: type: object description: Guardrails validators applied to application input and output. properties: enable_guard_rails: type: boolean input_validators: type: array items: $ref: '#/components/schemas/GuardrailValidatorEntry' output_validators: type: array items: $ref: '#/components/schemas/GuardrailValidatorEntry' ValidationErrorResponse: type: object description: Returned when request body or query parameters fail validation. properties: success: type: boolean example: false message: type: string example: Invalid request body description: Summary of the validation failure. errors: type: array description: Per-field validation errors. items: type: object properties: path: type: string description: >- JSON path to the invalid field (for example `traces.0.prompt`). message: type: string description: Why the field failed validation. ErrorResponse: type: object description: Standard error envelope for non-validation failures. properties: success: type: boolean example: false description: Always `false` for errors. message: type: string description: Human-readable explanation of the error. required: - success - message responses: ValidationError: description: >- The request body or query parameters are invalid. See the `errors` array for field-level detail. content: application/json: schema: $ref: '#/components/schemas/ValidationErrorResponse' example: success: false message: Invalid request body errors: - path: name message: name is required Unauthorized: description: >- The API key is missing, invalid, or revoked. Verify the `x-api-key` header and that the key is active in Trusys settings. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: message: Error while verifying api key NotFound: description: The requested resource does not exist, or your API key cannot access it. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: success: false message: Application not found securitySchemes: ApiKeyAuth: type: apiKey in: header name: x-api-key description: >- Your Trusys API key. Create and manage keys in the Trusys UI under **Settings → API Keys**. Include the key on every request: ``` x-api-key: ``` ````