> ## Documentation Index > Fetch the complete documentation index at: https://docs.trychannel3.com/llms.txt > Use this file to discover all available pages before exploring further. # Create Product Subscription > Subscribe to a canonical product's offer events; an identical active subscription returns the existing one. ## OpenAPI ````yaml post /v1/product-subscriptions openapi: 3.1.0 info: title: Channel3 API version: 0.1.0 servers: - url: https://api.trychannel3.com description: Production security: [] paths: /v1/product-subscriptions: post: tags: - product-subscriptions summary: Create Product Subscription description: >- Subscribe to a canonical product's offer events; an identical active subscription returns the existing one. operationId: create_product_subscription_v1_product_subscriptions_post requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CreateProductSubscriptionRequest' responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/ProductSubscriptionResponse' '401': description: Unauthorized - Invalid or missing authentication content: application/json: examples: missing_key: summary: Missing API Key value: detail: >- Unauthorized. Missing authentication key. Make sure to attach an x-api-key with your request. Need help? Reach out to support@trychannel3.com. invalid_key: summary: Invalid API Key value: detail: >- API key was provided but is invalid. Need help? Reach out to support@trychannel3.com. schema: $ref: '#/components/schemas/app__routers__utils__ErrorResponse' '402': description: Payment required content: application/json: examples: credits_exhausted: summary: API key out of credits value: detail: >- You have used all of your free credits. Add a payment method to continue. mpp_challenge: summary: MPP Tempo payment required value: detail: >- Payment required. Satisfy the MPP Tempo challenge in WWW-Authenticate. schema: $ref: '#/components/schemas/app__routers__utils__ErrorResponse' '404': description: Not found content: application/json: example: detail: Canonical product cp_123 not found schema: $ref: '#/components/schemas/app__routers__utils__ErrorResponse' '409': description: The product is not available yet content: application/json: example: detail: >- Product cp_123 is still being processed from its lookup; retry with the same ID once the lookup resolves schema: $ref: '#/components/schemas/app__routers__utils__ErrorResponse' '422': description: Invalid event types, domains, or selection content: application/json: example: detail: 'Invalid domain: ''nike''. Pass bare domains like ''nike.com''.' schema: $ref: '#/components/schemas/app__routers__utils__ErrorResponse' '500': description: Internal Server Error content: application/json: schema: $ref: '#/components/schemas/app__routers__utils__ErrorResponse' example: detail: Internal Server Error security: - APIKeyHeader: [] components: schemas: CreateProductSubscriptionRequest: properties: product_id: type: string title: Product Id description: >- Canonical product ID, as returned by /v1/products or /v1/lookup. Lookup IDs are canonicalized automatically; if the lookup is still processing, creation fails with 409 — retry with the same ID events: items: type: string enum: - offer.price.changed - offer.availability.changed - offer.created - offer.deleted type: array minItems: 1 title: Events description: Offer event types to receive. domains: anyOf: - items: type: string type: array - type: 'null' title: Domains description: >- Restrict events to offers on these merchant domains (e.g. nike.com, max 25). Omitted = every offer. selection: anyOf: - items: $ref: '#/components/schemas/SelectedOption' type: array minItems: 1 - type: 'null' title: Selection description: >- Pin the subscription to one variant configuration: one {name, label} per configurable dimension, in the shape of `variants.selected` on the product detail response. type: object required: - product_id - events title: CreateProductSubscriptionRequest description: >- What to subscribe to: a canonical product's offer events, optionally narrowed by merchant domains and a variant selection. ProductSubscriptionResponse: properties: subscription_id: type: string title: Subscription Id product_id: type: string title: Product Id events: items: type: string enum: - offer.price.changed - offer.availability.changed - offer.created - offer.deleted type: array title: Events domains: anyOf: - items: type: string type: array - type: 'null' title: Domains selection: anyOf: - items: $ref: '#/components/schemas/StoredSelection' type: array - type: 'null' title: Selection locale: $ref: '#/components/schemas/WebhookLocale' status: $ref: '#/components/schemas/ProductSubscriptionStatus' description: 'Lifecycle status: "active" or "cancelled"' created_at: type: string format: date-time title: Created At type: object required: - subscription_id - product_id - events - locale - status - created_at title: ProductSubscriptionResponse description: A product subscription's scope and lifecycle state. app__routers__utils__ErrorResponse: properties: detail: anyOf: - type: string - items: additionalProperties: true type: object type: array title: Detail type: object required: - detail title: ErrorResponse SelectedOption: properties: name: type: string title: Name description: The name of the selected option (e.g. 'Color', 'Size') label: type: string title: Label description: The display value of the selected option (e.g. 'Blue', 'XL') type: object required: - name - label title: SelectedOption description: One effective selection on a product, post server-side relaxation. StoredSelection: properties: name: type: string title: Name label: type: string title: Label value_key: type: string title: Value Key type: object required: - name - label - value_key title: StoredSelection description: >- One pinned variant dimension (e.g. Size = L); `value_key` is the standardized identifier for the value. WebhookLocale: properties: language: $ref: '#/components/schemas/LanguageCode' country: anyOf: - $ref: '#/components/schemas/CountryCode' - type: 'null' currency: $ref: '#/components/schemas/CurrencyCode' type: object required: - language - currency title: WebhookLocale description: The locale the subscription reads the product in. ProductSubscriptionStatus: type: string enum: - active - cancelled title: ProductSubscriptionStatus LanguageCode: type: string enum: - en - de - fr - it - es - nl - sv - fi - pt - cs - el - ro - pl title: LanguageCode description: ISO 639-1 language code. CountryCode: type: string enum: - US - GB - EU - AU - CA - IE - DE - AT - FR - BE - IT - ES - NL - SE - FI - PT - CZ - GR - RO - CH - PL title: CountryCode description: ISO 3166-1 alpha-2 country code (plus the pan-region ``EU``). CurrencyCode: type: string enum: - USD - CAD - AUD - GBP - EUR - SEK - CZK - RON - CHF - PLN title: CurrencyCode description: ISO 4217 currency code. securitySchemes: APIKeyHeader: type: apiKey in: header name: x-api-key ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.