> ## 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. # Respond to a demand signal > Record a seller action (QUOTE / CLARIFY / DECLINE / BOOK) against a demand signal routed to the caller's storefront. Transactional: writes the response, advances the per-target dispatch_status (ACKNOWLEDGED for QUOTE/CLARIFY/BOOK, DECLINED for DECLINE), and re-evaluates the parent signal status. BOOK is terminal — once a signal is BOOKED it cannot move backward. ## OpenAPI ````yaml /v2/storefront-api-v2.yaml post /storefronts/{storefrontId}/demand-signals/{signalId}/respond openapi: 3.0.0 info: title: Scope3 Storefront API version: 2.0.0 description: |- REST API for partners to manage storefronts, inventory sources, and billing. ## Authentication All endpoints require a Bearer token in the Authorization header: ``` Authorization: Bearer your-api-key ``` ## Base URL `https://api.interchange.io/api/v2/storefront` ## For AI Agents AI agents can use the MCP endpoint at `/mcp/v2/storefront` 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/storefront description: Production server security: [] tags: - name: Account description: Account management, service tokens, and preferences - name: Storefront description: Manage storefront and inventory sources - name: Storefront Agents description: List and manage registered sales, signals, and outcomes agents - name: Storefront Activity description: Audit log of configuration and inventory changes on the storefront - name: Storefront Billing description: Payout bank details and billing configuration for storefronts - name: AI Usage description: Storefront AI token usage visibility by model - name: MCP description: Model Context Protocol endpoints paths: /storefronts/{storefrontId}/demand-signals/{signalId}/respond: post: tags: - Demand Signals summary: Respond to a demand signal description: >- Record a seller action (QUOTE / CLARIFY / DECLINE / BOOK) against a demand signal routed to the caller's storefront. Transactional: writes the response, advances the per-target dispatch_status (ACKNOWLEDGED for QUOTE/CLARIFY/BOOK, DECLINED for DECLINE), and re-evaluates the parent signal status. BOOK is terminal — once a signal is BOOKED it cannot move backward. operationId: respondToDemandSignal parameters: - in: path name: storefrontId schema: type: integer maximum: 9007199254740991 minimum: 1 required: true - in: path name: signalId schema: type: integer maximum: 9007199254740991 minimum: 1 required: true requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/RespondToDemandSignalBody' responses: '201': description: Respond to a demand signal content: application/json: schema: $ref: '#/components/schemas/DemandSignalResponse' '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: >- Feature not enabled for this customer (PostHog `demand-supply-signals`) or caller does not own the storefront. 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: RespondToDemandSignalBody: oneOf: - type: object properties: kind: type: string enum: - QUOTE payload: $ref: '#/components/schemas/DemandSignalQuotePayload' required: - kind - payload - type: object properties: kind: type: string enum: - CLARIFY payload: $ref: '#/components/schemas/DemandSignalClarifyPayload' required: - kind - payload - type: object properties: kind: type: string enum: - DECLINE payload: $ref: '#/components/schemas/DemandSignalDeclinePayload' required: - kind - payload - type: object properties: kind: type: string enum: - BOOK payload: $ref: '#/components/schemas/DemandSignalBookPayload' required: - kind - payload type: object DemandSignalResponse: description: A seller action against a demand_signal_target. type: object properties: id: type: string demandSignalId: type: string demandSignalTargetId: type: string sellerCustomerId: type: integer minimum: -9007199254740991 maximum: 9007199254740991 storefrontId: nullable: true type: string kind: type: string enum: - QUOTE - CLARIFY - DECLINE - BOOK payload: nullable: true type: object additionalProperties: {} matchScore: nullable: true type: integer minimum: 0 maximum: 100 actorUserId: nullable: true type: integer minimum: -9007199254740991 maximum: 9007199254740991 createdAt: type: string proposalCode: description: >- Storefront proposal code (e.g. "PRP-XK4A29") minted alongside a QUOTE so the buyer's agent can redeem the offer via discover_products. Null when the seller declined, or when operator resolution failed at QUOTE time. nullable: true type: string required: - id - demandSignalId - demandSignalTargetId - sellerCustomerId - storefrontId - kind - payload - matchScore - actorUserId - 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 DemandSignalQuotePayload: type: object properties: proposedCpm: type: number minimum: 0 exclusiveMinimum: true currency: type: string minLength: 3 maxLength: 3 products: type: array items: type: object properties: productId: type: string name: type: string estimatedImpressions: type: integer minimum: 0 maximum: 9007199254740991 required: - productId notes: type: string maxLength: 4000 required: - proposedCpm - currency DemandSignalClarifyPayload: type: object properties: question: type: string minLength: 1 maxLength: 4000 gaps: type: array items: type: string required: - question DemandSignalDeclinePayload: type: object properties: reason: type: string minLength: 1 maxLength: 4000 required: - reason DemandSignalBookPayload: type: object properties: dealId: type: string minLength: 1 notes: type: string maxLength: 4000 required: - dealId 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 ````