> ## Documentation Index > Fetch the complete documentation index at: https://docs.usenexio.com/llms.txt > Use this file to discover all available pages before exploring further. # Validate Engine Config > Dry-run a configuration change to surface validation errors without modifying the live engine. ## OpenAPI ````yaml POST /api/v1/engines/{engine_slug}/config/validate openapi: 3.1.0 info: title: Nexio API version: '1.0' description: | Nexio agentic infrastructure API. Configure engines for placement, entity analysis, and other patterns. Submit runs, poll for results, or subscribe to signed webhook callbacks. contact: email: support@usenexio.com url: https://docs.usenexio.com servers: - url: https://api.usenexio.com description: Production security: - BearerAuth: [] tags: - name: EngineManagement description: Create, configure, and manage inference engines. - name: Engines description: Engine-scoped endpoints for submitting runs and retrieving results. - name: Runs description: Retrieve and reconcile submitted runs. - name: Catalog description: >- Read current carriers and products extracted for the authenticated organization. - name: Environments description: Isolated tenancy scopes under your org (one live plus non-live sandboxes). - name: Webhooks description: Manage webhook endpoints for push-based delivery of terminal run events. paths: /api/v1/engines/{engine_slug}/config/validate: post: tags: - EngineManagement summary: Validate Engine Config description: | Dry-run validation of a config object against the engine's type-specific rules. The config is **not saved**: use this to check for errors before calling [Update Engine Config](/api-reference/engines/update-engine-config). Always returns `200 OK` with a `valid` boolean and an `errors` array. If `valid` is `true`, the `errors` array is empty. operationId: validateEngineConfig parameters: - $ref: '#/components/parameters/EngineSlug' requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/ConfigUpdateRequest' example: config: schema_version: 1 pack_key: insurance-personal-lines pack_version: 1 responses: '200': description: Validation result. content: application/json: schema: $ref: '#/components/schemas/ValidateConfigResponse' examples: valid: summary: Config is valid value: valid: true errors: [] invalid: summary: Config has errors value: valid: false errors: - path: schema_version message: schema_version must be 1 - path: scoring_dimensions message: at least one scoring dimension is required '400': description: Malformed request. content: application/json: schema: $ref: '#/components/schemas/Error' example: code: invalid_request message: config is required '401': $ref: '#/components/responses/Unauthorized' '404': $ref: '#/components/responses/EngineNotFound' '429': $ref: '#/components/responses/RateLimited' components: parameters: EngineSlug: name: engine_slug in: path required: true description: Engine identifier slug (e.g. `default`). schema: type: string schemas: ConfigUpdateRequest: type: object required: - config properties: config: type: object additionalProperties: true description: | Full replacement config. Must conform to the engine's type-specific schema. Use the [validate endpoint](/api-reference/engines/validate-engine-config) to check before saving. ValidateConfigResponse: type: object required: - valid - errors properties: valid: type: boolean description: Whether the config passes all validation rules. errors: type: array description: Validation issues found. Empty when `valid` is `true`. items: $ref: '#/components/schemas/ValidationIssue' Error: type: object required: - code - message properties: code: type: string description: | Stable snake_case error identifier. Safe to match programmatically. Known codes: `invalid_request`, `invalid_input`, `unauthorized`, `auth_unavailable`, `rate_limited`, `missing_run_id`, `invalid_run_id`, `run_not_found`, `invalid_offerings`, `missing_input`, `queue_unreachable`, `engine_not_found`, `engine_slug_conflict`, `engine_archived`, `invalid_engine_type`, `validation_error`, `webhook_not_found`, `webhook_limit_exceeded`, `invalid_url`, `invalid_events`, `invalid_description`, `invalid_auth_token`, `missing_endpoint_id`, `invalid_endpoint_id`, `missing_delivery_id`, `invalid_delivery_id`, `delivery_not_found`, `delivery_not_resendable`, `insufficient_capability`, `engine_version_required`, `engine_version_exact_required`, `engine_version_not_found`, `engine_version_invalid_format`, `engine_version_draft_requires_sandbox_key`, `engine_version_none_released`, `test_scenario_sandbox_only`, `test_scenario_forbidden`, `test_scenario_exact_version_required`, `test_scenario_version_not_supported`, `invalid_test_scenario`, `request_bound_exceeded`, and `run_cap_exceeded`. message: type: string description: Human-readable error message. May change between versions. details: description: | Optional request-specific details. Request-bound failures use the `RequestBoundDetails` object. Validation failures may use an array of field issues or another documented object. ValidationIssue: type: object required: - path - message properties: path: type: string description: JSON path to the invalid field (e.g. `scoring_dimensions.0.key`). message: type: string description: Human-readable error description. responses: Unauthorized: description: Missing or invalid API key. content: application/json: schema: $ref: '#/components/schemas/Error' example: code: unauthorized message: Missing or invalid API key EngineNotFound: description: Engine not found. content: application/json: schema: $ref: '#/components/schemas/Error' example: code: engine_not_found message: Engine not found RateLimited: description: Rate limit exceeded. Retry after the window resets. headers: Retry-After: description: Seconds until the rate limit window resets. schema: type: integer content: application/json: schema: $ref: '#/components/schemas/Error' example: code: rate_limited message: Rate limit exceeded securitySchemes: BearerAuth: type: http scheme: bearer description: | Send the credential as `Authorization: Bearer `. Scoped partner credentials use the exclusive `nxsk_v1_...` namespace. Each scoped key is bound at issuance to one organization, one canonical named environment, an explicit engine set, and a least-privilege capability set. A malformed, unknown, rotated, or revoked `nxsk_` key fails closed and is never retried as a legacy key. Capabilities used by this API are `runs:write`, `runs:read`, `engines:read`, `catalog:read`, `webhooks:manage`, `runs:defensibility:read`, `runs:test`, and `converse:use`. Operation descriptions name the required capability. Grandfathered `nx_live_...` and `nx_test_...` keys retain their existing broad access during the compatibility window. ````