> ## 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. # Register an AWS delegated grant > Registers the AWS delegated-grant coordinates for an AWS-sink subscription (`sqs`, `eventbridge`) — the non-secret cross-account delivery role ARN, region, and destination the dispatcher assumes at delivery time. This is the write that follows the customer applying the setup-artifacts trust policy in their AWS account. It is write-only: it runs no inline probe and does not change the verification state (a registered grant stays `pending_verification` until a later `verify`). No AWS credential crosses this body. The destination host is validated before the write. A non-AWS sink returns `422 validation_error`. ## OpenAPI ````yaml en/openapi/v3-current/streaming-hub.yaml put /v1/subscriptions/{id}/delegated-grant 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}/delegated-grant: put: tags: - Subscriptions summary: Register an AWS delegated grant description: >- Registers the AWS delegated-grant coordinates for an AWS-sink subscription (`sqs`, `eventbridge`) — the non-secret cross-account delivery role ARN, region, and destination the dispatcher assumes at delivery time. This is the write that follows the customer applying the setup-artifacts trust policy in their AWS account. It is write-only: it runs no inline probe and does not change the verification state (a registered grant stays `pending_verification` until a later `verify`). No AWS credential crosses this body. The destination host is validated before the write. A non-AWS sink returns `422 validation_error`. operationId: putSubscriptionDelegatedGrant parameters: - $ref: '#/components/parameters/SubscriptionId' - $ref: '#/components/parameters/IdempotencyKey' requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/DelegatedGrantRequest' responses: '200': description: >- The grant was persisted (no body; the verification state is unchanged). headers: X-Idempotency-Replayed: $ref: '#/components/headers/IdempotencyReplayed' '400': $ref: '#/components/responses/BadRequestOrMissingIdempotency' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' '409': $ref: '#/components/responses/IdempotencyConflict' '422': description: >- The request is caller-correctable. `error` is `validation_error` (a missing `roleArn` / `region` / `destination`, or a non-AWS sink) or `endpoint_blocked` (the destination 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 IdempotencyKey: name: X-Idempotency in: header required: true description: >- A client-chosen unique key that makes this mutation at-most-once. A mutation sent without it is rejected before any write with `400 missing_idempotency_key`. Reusing the same key with an identical request replays the original response byte-for-byte (with `X-Idempotency-Replayed: true`); reusing it with a different request body returns `409 idempotency_conflict`. To re-drive a corrected request, mint a new key. schema: type: string schemas: DelegatedGrantRequest: type: object additionalProperties: false description: >- The non-secret AWS delegated-grant coordinates. No AWS credential crosses this body — the role is assumed per delivery, guarded by the separately minted `ExternalId`. properties: roleArn: type: string description: >- The cross-account delivery role ARN Streaming Hub assumes at delivery time. examples: - arn:aws:iam::444455556666:role/streaming-hub-delegated-delivery region: type: string description: The AWS region of the destination. examples: - us-east-1 destination: type: string description: >- The resolved destination (queue URL or event-bus ARN). SSRF-validated before the write. examples: - https://sqs.us-east-1.amazonaws.com/444455556666/orders required: - roleArn - region - destination 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 headers: IdempotencyReplayed: description: >- Present and set to `true` when this response is a replay of a previously committed request carrying the same `X-Idempotency` key (the handler did not run again). schema: type: string enum: - 'true' responses: BadRequestOrMissingIdempotency: description: >- The request body is malformed (`bad_request`) or the required `X-Idempotency` header is missing (`missing_idempotency_key`, rejected before any write). 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' IdempotencyConflict: description: >- An in-flight duplicate, or the same `X-Idempotency` key was reused with a different request fingerprint — `error` is `idempotency_conflict`. 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. ````