> ## 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. # Replace exact advertiser access for a buyer agent > Reconcile the buyer agent’s exact advertiser list. Missing advertisers are revoked and role changes revoke then create a new append-only grant row. Only a directly authenticated WorkOS organization administrator may call this endpoint; registration, credentials, membership, domains, and operator identity grant no advertiser access. ## OpenAPI ````yaml /v2/buyer-api-v2.yaml put /buyer-agent-principals/{principalId}/access 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: /buyer-agent-principals/{principalId}/access: servers: - url: https://api.interchange.io/api/v2 description: Production server put: tags: - Buyer Agent Principals summary: Replace exact advertiser access for a buyer agent description: >- Reconcile the buyer agent’s exact advertiser list. Missing advertisers are revoked and role changes revoke then create a new append-only grant row. Only a directly authenticated WorkOS organization administrator may call this endpoint; registration, credentials, membership, domains, and operator identity grant no advertiser access. operationId: replaceBuyerAgentPrincipalAccess parameters: - in: path name: principalId schema: type: string pattern: ^prin_[A-Za-z0-9_-]{32}$ required: true requestBody: required: true content: application/json: schema: type: object properties: expectedAccessRevision: type: integer minimum: 0 maximum: 9007199254740991 advertisers: maxItems: 500 type: array items: type: object properties: advertiserId: type: string pattern: ^[1-9][0-9]{0,18}$ role: type: string enum: - READ - READ_WRITE required: - advertiserId - role additionalProperties: false required: - expectedAccessRevision - advertisers additionalProperties: false description: Replace the exact advertiser access list for one buyer agent. responses: '200': description: Replace exact advertiser access for a buyer agent content: application/json: schema: $ref: >- #/components/schemas/BuyerAgentPrincipalAccessUpdateApiResponse '400': description: Bad request content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '401': description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '403': description: >- The caller is not a directly authenticated WorkOS organization administrator, the principal is outside the verified organization, or an advertiser is outside the organization. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '404': description: >- No active buyer-agent principal with this identifier exists in the verified organization. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '409': description: >- The submitted access revision is stale; reload the current access before saving. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '500': description: Internal server error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '503': description: Buyer-agent advertiser authorization is temporarily unavailable. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' security: - bearerAuth: [] components: schemas: BuyerAgentPrincipalAccessUpdateApiResponse: type: object properties: data: type: object properties: access: type: object properties: accessRevision: type: integer minimum: 0 maximum: 9007199254740991 advertisers: type: array items: type: object properties: advertiserId: type: string pattern: ^[1-9][0-9]{0,18}$ name: type: string minLength: 1 role: type: string enum: - READ - READ_WRITE required: - advertiserId - name - role additionalProperties: false required: - accessRevision - advertisers additionalProperties: false required: - access additionalProperties: false error: type: string nullable: true enum: - null required: - data - error additionalProperties: false 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 ````