> ## 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. # List Class Knowledge > Page through per-class underwriting knowledge, filtered by NAICS code prefix or title search. ## OpenAPI ````yaml GET /api/v1/catalog/class-knowledge 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 markets 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. - name: Converse description: The raw stateless conversational model turn (caller-owned state). - name: Conversations description: >- Conversation instances (orchestrators over engines) and their managed conversations, turns, annotations, evals, and exports. paths: /api/v1/catalog/class-knowledge: get: tags: - Catalog summary: List Class Knowledge description: | Returns one page of per-industry-class knowledge entries for the authenticated organization, keyed by NAICS/SIC code. Each entry carries a `sources` array naming the class-level sources behind it; today the only source kind is `ambest_bur` (AM Best Business Underwriting Reports), and future source kinds append entries additively without a contract break. `naics` matches codes by prefix (a full 6-digit code is an exact match); a code can map to more than one entry. Scoped credentials require `catalog:read`. operationId: listClassKnowledge parameters: - name: naics in: query required: false schema: type: string maxLength: 10 pattern: ^[0-9]+$ description: NAICS code prefix filter. - $ref: '#/components/parameters/CatalogSearch' - $ref: '#/components/parameters/CatalogPage' - $ref: '#/components/parameters/CatalogPageSize' responses: '200': description: One page of class-knowledge entries with corpus totals. content: application/json: schema: $ref: '#/components/schemas/ClassKnowledgeListResponse' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '429': $ref: '#/components/responses/RateLimited' '503': $ref: '#/components/responses/AuthUnavailable' components: parameters: CatalogSearch: name: search in: query description: Case-insensitive substring matched over the line label or market name. schema: type: string CatalogPage: name: page in: query description: 1-based page number. Defaults to 1. schema: type: integer minimum: 1 default: 1 CatalogPageSize: name: page_size in: query description: Rows per page, clamped to 100. Defaults to 25. schema: type: integer minimum: 1 maximum: 100 default: 25 schemas: ClassKnowledgeListResponse: type: object additionalProperties: false required: - items - page - page_size - total_matched - total_corpus properties: items: type: array items: $ref: '#/components/schemas/ClassKnowledgeItem' page: type: integer page_size: type: integer total_matched: type: integer total_corpus: type: integer ClassKnowledgeItem: type: object additionalProperties: false required: - id - source_report_id - title - codes - am_publish_date - sources properties: id: type: string format: uuid source_report_id: type: string title: type: string codes: type: array items: $ref: '#/components/schemas/ClassKnowledgeCode' am_publish_date: type: string nullable: true sources: type: array items: $ref: '#/components/schemas/ClassKnowledgeSource' 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`, `instance_not_found`, `instance_slug_conflict`, `instance_archived`, `instance_follows_canonical`, `instance_not_published`, `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. ClassKnowledgeCode: type: object additionalProperties: false required: - code_type - code - classification - naics_2022_classification properties: code_type: type: string enum: - naics - sic code: type: string classification: type: string naics_2022_classification: type: string nullable: true ClassKnowledgeSource: type: object additionalProperties: false required: - kind - as_of - label properties: kind: type: string description: >- Source kind. Today only `ambest_bur`; future kinds append additively. as_of: type: string nullable: true description: The source's publish/as-of date (YYYY-MM-DD); null when unstated. label: type: string description: Provenance label of the load that produced the rows. responses: BadRequest: description: Invalid request. content: application/json: schema: $ref: '#/components/schemas/Error' examples: invalidRequest: summary: Malformed JSON value: code: invalid_request message: Request body is not valid JSON invalidInput: summary: Input validation failed value: code: invalid_input message: Input failed validation details: - field: input.address.state message: address.state is required for placement runs. invalidOfferings: summary: Placement run missing offerings value: code: invalid_offerings message: Inline offerings failed validation details: - field: offerings message: >- Offerings are required for placement runs. Pass provider offerings in the top-level offerings array. Unauthorized: description: Missing or invalid API key. content: application/json: schema: $ref: '#/components/schemas/Error' example: code: unauthorized message: Missing or invalid API key Forbidden: description: Scoped key does not have the capability required by this operation. content: application/json: schema: $ref: '#/components/schemas/Error' example: code: insufficient_capability message: API key does not have permission for this action 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 AuthUnavailable: description: API key authentication is temporarily unavailable. content: application/json: schema: $ref: '#/components/schemas/Error' example: code: auth_unavailable message: API key authentication is temporarily unavailable 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`, `conversations:use`, and `conversations:export`. Operation descriptions name the required capability. Grandfathered `nx_live_...` and `nx_test_...` keys retain their existing broad access during the compatibility window. ````