> ## Documentation Index > Fetch the complete documentation index at: https://docs.lerian.studio/llms.txt > Use this file to discover all available pages before exploring further. # List the event catalog > Returns the manifest-fed catalog snapshot — the last-known-good aggregation of the producer manifests Streaming Hub tracks. The catalog is global in v1 (byte-identical regardless of which tenant authenticates) and control-plane only; the data plane never consults it. An empty snapshot returns `200` with `events: []` (fail-closed to last-known-good — never an error on an empty catalog). ## OpenAPI ````yaml en/openapi/v3-current/streaming-hub.yaml get /v1/catalog openapi: 3.1.0 info: title: Lerian Streaming Hub API version: v1.0.0 contact: email: contact@lerian.studio name: Lerian Studio url: https://lerian.studio license: name: Lerian Studio General License description: >- The Streaming Hub control-plane API. Streaming Hub is Lerian's managed event-delivery edge: it consumes CloudEvents from the platform's internal streaming backbone and fans them out to a tenant's own external destinations — webhooks, Amazon SQS, RabbitMQ, Amazon EventBridge, or a pull inbox. This API lets a tenant browse the manifest-fed event catalog, create and manage delivery subscriptions, verify and rotate their credentials, read delivery health, and pull entitled events. Errors follow RFC 9457 `application/problem+json`: every hub-owned error body carries `type`, `title`, `status`, `detail`, and a stable low-cardinality `code` you can branch on. For `5xx` responses the `detail` is scrubbed to a static `"internal error"` so no internal cause leaks. Mutating operations require an `X-Idempotency` header for at-most-once semantics; a replayed request returns the original response byte-for-byte with `X-Idempotency-Replayed: true`. The catalog and the pull events surface are tenant-scoped through the bearer JWT; the operational probe endpoints (`/healthz`, `/readyz`, `/version`, `/runtime`, `/metrics`) are unauthenticated. Streaming Hub is closed source under the Lerian Studio General License. servers: - url: https://streaming-hub.sandbox.lerian.net security: - BearerAuth: [] tags: - name: Catalog description: Browse the manifest-fed catalog of event types available for subscription. - name: Subscriptions description: >- Create, read, update, and delete delivery subscriptions, and drive the destination verification lifecycle (ping, verify, credential, delegated grant, secret rotation, health). - name: Event Delivery description: >- Pull entitled events for a pull-sink subscription (cursor-as-acknowledgment read). - name: Admin description: Cross-tenant operator forensics. Requires an operator authorization scope. - name: Operational description: Unauthenticated liveness, readiness, build, runtime, and metrics probes. paths: /v1/catalog: get: tags: - Catalog summary: List the event catalog description: >- Returns the manifest-fed catalog snapshot — the last-known-good aggregation of the producer manifests Streaming Hub tracks. The catalog is global in v1 (byte-identical regardless of which tenant authenticates) and control-plane only; the data plane never consults it. An empty snapshot returns `200` with `events: []` (fail-closed to last-known-good — never an error on an empty catalog). operationId: getCatalog responses: '200': description: The catalog snapshot. content: application/json: schema: $ref: '#/components/schemas/CatalogResponse' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '500': $ref: '#/components/responses/InternalError' security: - BearerAuth: [] components: schemas: CatalogResponse: type: object additionalProperties: false properties: events: type: array description: >- The catalog entries in deterministic (topic, schemaMajor, eventType) order. Empty when the snapshot is empty. items: $ref: '#/components/schemas/CatalogEvent' availableMajors: type: object additionalProperties: type: array items: type: integer description: >- Per topic, the set of distinct schema-major values present in the snapshot, each ascending. An empty object when the snapshot is empty. examples: - lerian.streaming.transaction.created: - 1 required: - events - availableMajors CatalogEvent: type: object additionalProperties: false properties: eventType: type: string description: The event type (the `.` tail). examples: - transaction.created topic: type: string description: The Kafka topic the event is published on. examples: - lerian.streaming.transaction.created schemaVersion: type: string description: The full schema version. examples: - 1.0.0 schemaMajor: type: integer description: The schema major. examples: - 1 dataSchema: type: string description: >- An opaque schema URL passthrough. Omitted when empty; Streaming Hub never resolves or fetches it. examples: - https://schemas.example.com/transaction/created/1.json description: type: string description: A human-readable description of the event. examples: - A transaction was created. required: - eventType - topic - schemaVersion - schemaMajor - description Error: type: object description: >- RFC 9457 `application/problem+json` document returned for every hub-owned error across the `/v1` and `/admin` surfaces. The stable `code` is what a client branches on; `detail` is a caller-safe explanation and, for any `5xx`, is centrally scrubbed to `"internal error"` so no internal cause can leak. (A `403` from the authorization decision point ahead of the hub is the one exception — its body is plain text.) properties: type: type: string format: uri description: >- A stable, versioned URI identifying the problem type (`https://errors.lerian.studio/v1/`), or `about:blank` for problems without a hub-assigned code. examples: - https://errors.lerian.studio/v1/not_found title: type: string description: A short human-readable summary — the HTTP status text. examples: - Not Found status: type: integer description: The HTTP status code, mirrored in the body. examples: - 404 detail: type: string description: >- A caller-safe human explanation of this specific occurrence. For `5xx` responses this is always the static string `"internal error"`. examples: - subscription not found code: type: string description: >- The stable, low-cardinality, machine-readable token a client branches on (for example `not_found`, `unauthorized`, `idempotency_conflict`, `validation_error`). Empty for huma-native validation faults. examples: - not_found required: - type - title - status responses: Unauthorized: description: >- Authentication failed, or there is no trusted tenant context. `code` is `unauthorized` (uniform body — no reason is leaked). content: application/problem+json: schema: $ref: '#/components/schemas/Error' Forbidden: description: >- The authorization decision point denied the request. The body is emitted by lib-auth ahead of the hub and is currently plain text (not `application/problem+json`). content: text/plain: schema: type: string InternalError: description: >- An infrastructure fault. `code` is `internal_error` and `detail` is scrubbed to the static `"internal error"` (the cause is logged, never returned). content: application/problem+json: schema: $ref: '#/components/schemas/Error' securitySchemes: BearerAuth: type: http scheme: bearer bearerFormat: JWT description: >- A bearer JWT issued by plugin-auth (lib-auth). The tenant identity is resolved from the validated token claims; the `/v1` surface never reads a tenant from the body, path, or query. Machine callers obtain a token via the plugin-auth client-credentials flow. The `/admin` surface authorizes against an operator scope and carries no tenant context. ````