> ## 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. # Set or rotate a queue credential > Sets or rotates the outbound credential for a queue subscription (`sqs`, `rabbitmq`, `eventbridge`) with probe-on-write: the candidate credential is held in memory, probed (connect + auth) immediately, and persisted encrypted only on probe success — a failed probe stores nothing. A successful probe flips the subscription from `pending_verification` to `active`. The credential is write-only: it is supplied only here and is never returned, not even masked, on any read path. A classified probe failure is still a `200`. This route is naturally idempotent and requires no `X-Idempotency` header. ## OpenAPI ````yaml en/openapi/v3-current/streaming-hub.yaml put /v1/subscriptions/{id}/credential 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 use a flat `{"error":""}` envelope (a low-cardinality, machine-readable token — never RFC 9457 problem+json). 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/subscriptions/{id}/credential: put: tags: - Subscriptions summary: Set or rotate a queue credential description: >- Sets or rotates the outbound credential for a queue subscription (`sqs`, `rabbitmq`, `eventbridge`) with probe-on-write: the candidate credential is held in memory, probed (connect + auth) immediately, and persisted encrypted only on probe success — a failed probe stores nothing. A successful probe flips the subscription from `pending_verification` to `active`. The credential is write-only: it is supplied only here and is never returned, not even masked, on any read path. A classified probe failure is still a `200`. This route is naturally idempotent and requires no `X-Idempotency` header. operationId: putSubscriptionCredential parameters: - $ref: '#/components/parameters/SubscriptionId' requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CredentialRequest' responses: '200': description: >- The probe ran; the body carries the classified result. On success the credential was persisted and the subscription is `active`; on a classified failure nothing was persisted. content: application/json: schema: $ref: '#/components/schemas/ProbeResult' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' '422': description: >- The request is caller-correctable. `error` is `validation_error` (an absent or empty `sinkConfig`) or `endpoint_blocked` (the broker host resolved to a blocked, private, or metadata address). content: application/json: schema: $ref: '#/components/schemas/Error' '500': $ref: '#/components/responses/InternalError' security: - BearerAuth: [] components: parameters: SubscriptionId: name: id in: path required: true description: The unique identifier of the subscription (UUIDv7). schema: type: string format: uuid schemas: CredentialRequest: type: object additionalProperties: false description: >- The queue-credential body. `sinkConfig` is a kind-specific, write-only object that is probed and, on success, stored encrypted. It is never returned on any read path. properties: sinkConfig: type: object additionalProperties: true description: >- The candidate outbound credential for the queue kind. For `rabbitmq`, an object such as `{"uri":"amqps://user:pass@broker.example.com:5671/vhost"}`; for AWS kinds, the region and access material. Write-only — never logged or returned. examples: - uri: amqps://user:pass@broker.example.com:5671/vhost required: - sinkConfig ProbeResult: type: object additionalProperties: false description: >- The classified result of a synchronous probe (ping, verify, or credential write). A classified failure is still returned with HTTP `200` — the probe ran and produced a verdict. It carries no secret, endpoint, or detail string. properties: outcome: $ref: '#/components/schemas/Outcome' statusCode: type: integer description: >- The target's protocol status. For webhook probes, the HTTP status (`0` when none applies, e.g. a transport error or a blocked endpoint). For queue-kind credential probes, always `0`. examples: - 200 errorClass: type: string description: A frozen taxonomy token classifying a failure. Empty on success. examples: - '' required: - outcome - statusCode - errorClass Error: type: object additionalProperties: false description: >- The flat error envelope used across the `/v1` and `/admin` surfaces. It carries a single low-cardinality, machine-readable token and never leaks secret material or internal detail. (A `403` from the authorization decision point is the one exception — its body is plain text.) properties: error: type: string description: The machine-readable error token. examples: - not_found required: - error Outcome: type: string description: The classified verdict of a synchronous probe. enum: - ok - failed responses: BadRequest: description: The request body is malformed — `error` is `bad_request`. content: application/json: schema: $ref: '#/components/schemas/Error' Unauthorized: description: >- Authentication failed, or there is no trusted tenant context. `error` is `unauthorized` (uniform body — no reason is leaked). content: application/json: schema: $ref: '#/components/schemas/Error' Forbidden: description: >- The authorization decision point denied the request. The body is plain text (not the JSON error envelope). content: text/plain: schema: type: string NotFound: description: >- The resource is absent, soft-deleted, or owned by another tenant — a uniform `error` of `not_found` (no existence oracle). content: application/json: schema: $ref: '#/components/schemas/Error' InternalError: description: >- An infrastructure fault. `error` is `internal_error` (sanitized; detail is logged, never returned). content: application/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. ````