> ## Documentation Index > Fetch the complete documentation index at: https://docs.interchange.io/llms.txt > Use this file to discover all available pages before exploring further. # Declare sandbox buyer account linkages on a MANAGED storefront > Declare one or more sandbox account linkages between the calling buyer and a MANAGED storefront. Every entry must carry `sandbox: true` and `billing: 'agent'`. Delegates to the seller-side linking substrate: grants land in the same tables the seller-side inbound `sync_accounts` handler writes to. External-adapter, archived, and paused storefronts are rejected up-front. Production traffic (operator-identity gate, other billing modes) and buyer-side idempotency ship in follow-up slices; today the linking service is idempotent at its natural-key level `(storefront_id, operator_domain, brand_domain, sandbox)`. ## OpenAPI ````yaml /v2/buyer-api-v2.yaml post /storefront-accounts/sync openapi: 3.0.0 info: title: Scope3 Buyer API version: 2.0.0 description: |- REST API for advertisers to manage advertisers, campaigns, and reporting. ## Authentication All endpoints require a Bearer token in the Authorization header: ``` Authorization: Bearer your-api-key ``` ## Base URL `https://api.interchange.io/api/v2/buyer` ## For AI Agents AI agents can use the MCP endpoint at `/mcp/v2/buyer` with three tools: - `initialize`: Start an MCP session - `api_call`: Make REST API calls - `ask_about_capability`: Learn about API features servers: - url: https://api.interchange.io/api/v2/buyer description: Production server security: [] tags: - name: Signup description: Request reviewed access to Interchange - name: Account description: Account management, service tokens, and preferences - name: Asks description: >- What you are waiting on Scope3 for — support, product, and supply asks in one list - name: Advertisers description: Manage advertisers - name: Product Discovery description: Discover and select products - name: Campaigns description: Manage advertising campaigns - name: Creatives description: Build, manage, and sync campaign creatives via AdCP Creative Protocol - name: Reporting description: Access performance metrics - name: Event Sources description: >- Manage event source configurations and log conversion/marketing events for attribution - name: Property Lists description: Validate property lists against AAO registry - name: Sales Agents description: View and connect sales agents - name: Measurement description: Measurement sources, records, context, and freshness - name: Syndication description: Syndicate resources to ADCP agents - name: Tasks description: Track async operation status - name: Buyer Billing description: >- Consolidated invoicing for buyers — invoices and pending invoice items issued by Scope3 across the buyer customer. - name: MCP description: Model Context Protocol endpoints for AI agents paths: /storefront-accounts/sync: post: tags: - Buyer Storefront Accounts summary: Declare sandbox buyer account linkages on a MANAGED storefront description: >- Declare one or more sandbox account linkages between the calling buyer and a MANAGED storefront. Every entry must carry `sandbox: true` and `billing: 'agent'`. Delegates to the seller-side linking substrate: grants land in the same tables the seller-side inbound `sync_accounts` handler writes to. External-adapter, archived, and paused storefronts are rejected up-front. Production traffic (operator-identity gate, other billing modes) and buyer-side idempotency ship in follow-up slices; today the linking service is idempotent at its natural-key level `(storefront_id, operator_domain, brand_domain, sandbox)`. operationId: buyerSyncStorefrontAccounts requestBody: required: true content: application/json: schema: type: object properties: target: type: object properties: storefrontId: type: integer minimum: 0 exclusiveMinimum: true maximum: 9007199254740991 required: - storefrontId additionalProperties: false accounts: minItems: 1 maxItems: 100 type: array items: type: object properties: brand: type: object properties: domain: type: string pattern: >- ^[a-z0-9]([a-z0-9-]*[a-z0-9])?(\.[a-z0-9]([a-z0-9-]*[a-z0-9])?)*$ required: - domain additionalProperties: false operator: type: string pattern: >- ^[a-z0-9]([a-z0-9-]*[a-z0-9])?(\.[a-z0-9]([a-z0-9-]*[a-z0-9])?)*$ sandbox: type: boolean enum: - true billing: type: string enum: - agent required: - brand - operator - sandbox - billing additionalProperties: false dry_run: type: boolean required: - target - accounts additionalProperties: false responses: '200': description: Declare sandbox buyer account linkages on a MANAGED storefront content: application/json: schema: type: object properties: accounts: type: array items: type: object properties: brand: type: object properties: domain: type: string pattern: >- ^[a-z0-9]([a-z0-9-]*[a-z0-9])?(\.[a-z0-9]([a-z0-9-]*[a-z0-9])?)*$ required: - domain additionalProperties: {} operator: type: string minLength: 1 status: type: string enum: - active - pending_approval - rejected - payment_required - suspended - closed sandbox: type: boolean account_id: type: string minLength: 1 name: type: string minLength: 1 action: type: string enum: - created - updated - unchanged - failed required: - brand - operator - status - action additionalProperties: {} required: - accounts additionalProperties: false '400': description: Bad request content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '401': description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '500': description: Internal server error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' security: - bearerAuth: [] components: schemas: ErrorResponse: type: object properties: data: type: string nullable: true enum: - null error: $ref: '#/components/schemas/ApiError' required: - data - error additionalProperties: false description: Standard error response ApiError: type: object properties: code: type: string description: Machine-readable error code message: type: string description: Human-readable error message field: description: Field path associated with the error type: string details: description: Additional error context type: object additionalProperties: {} required: - code - message additionalProperties: false description: Structured error object securitySchemes: bearerAuth: type: http scheme: bearer description: API key or access token ````