> ## 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. # Register source credentials > Register credentials for an inventory source within a storefront. ## OpenAPI ````yaml /v2/buyer-api-v2.yaml post /storefronts/{storefrontId}/sources/{sourceId}/credentials 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: /storefronts/{storefrontId}/sources/{sourceId}/credentials: post: tags: - Storefronts summary: Register source credentials description: Register credentials for an inventory source within a storefront. operationId: registerSourceCredentials parameters: - in: path name: storefrontId schema: description: Storefront ID type: integer maximum: 9007199254740991 minimum: 1 required: true description: Storefront ID - in: path name: sourceId schema: description: Inventory source ID type: string minLength: 1 required: true description: Inventory source ID requestBody: required: true content: application/json: schema: type: object properties: accountIdentifier: description: Unique account identifier for this agent type: string minLength: 1 maxLength: 255 auth: description: >- Authentication credentials. Required for API_KEY/JWT/BASIC_AUTH agents, not needed for OAUTH agents. anyOf: - type: object properties: type: type: string enum: - jwt privateKey: type: string minLength: 1 issuer: type: string minLength: 1 subject: type: string minLength: 1 keyId: type: string minLength: 1 scope: type: string minLength: 1 tokenEndpointUrl: type: string format: uri audienceUrl: type: string format: uri algorithm: type: string enum: - ES256 - RS256 environment: type: string required: - type - privateKey - issuer - subject - keyId - scope - tokenEndpointUrl - audienceUrl - type: object properties: type: type: string enum: - bearer - apikey - api_key token: type: string minLength: 1 required: - type - token - type: object properties: type: type: string enum: - basic username: type: string minLength: 1 password: type: string required: - type - username - password - type: object properties: {} additionalProperties: false marketplaceAccount: description: >- Admin-only flag. When true, creates a marketplace account instead of a client account. type: boolean required: - accountIdentifier responses: '201': description: Register source credentials content: application/json: schema: $ref: '#/components/schemas/BuyerCredentialRegistrationResponse' '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: BuyerCredentialRegistrationResponse: description: >- Response for registering credentials against a storefront inventory source type: object properties: id: description: Credential record ID type: string accountIdentifier: description: The buyer's account identifier at the source type: string status: description: Credential status type: string registeredBy: description: >- Who registered this credential. Null on legacy rows that predate registration tracking. nullable: true type: string createdAt: description: When the credential was created (ISO 8601) type: string oauth: description: >- Present when the source uses OAuth — the buyer must visit `authorizationUrl` to complete consent allOf: - $ref: '#/components/schemas/BuyerCredentialOAuthInfo' required: - id - accountIdentifier - status - registeredBy - createdAt additionalProperties: false ErrorResponse: description: Standard error response type: object properties: data: type: string nullable: true enum: - null error: $ref: '#/components/schemas/ApiError' required: - data - error additionalProperties: false BuyerCredentialOAuthInfo: description: >- OAuth authorization info presented in buyer-facing storefront/source terms type: object properties: authorizationUrl: description: URL the buyer must visit to authorize type: string format: uri storefrontId: description: Storefront the OAuth flow was initiated for type: integer minimum: -9007199254740991 maximum: 9007199254740991 sourceId: description: Inventory source the OAuth flow was initiated for type: string sourceName: description: Inventory source display name type: string required: - authorizationUrl - storefrontId - sourceId - sourceName additionalProperties: false ApiError: description: Structured error object type: object properties: code: description: Machine-readable error code type: string message: description: Human-readable error message type: string field: description: Field path associated with the error type: string details: description: Additional error context type: object additionalProperties: {} required: - code - message additionalProperties: false securitySchemes: bearerAuth: type: http scheme: bearer description: API key or access token ````