openapi: 3.0.2 info: title: Klaviyo Accounts Conversations API version: '2026-04-15' description: The Klaviyo REST API. Please visit https://developers.klaviyo.com for more details. contact: name: Klaviyo Developer Experience Team email: developers@klaviyo.com url: https://developers.klaviyo.com termsOfService: https://www.klaviyo.com/legal/api-terms license: name: License url: https://www.klaviyo.com/legal servers: - url: https://a.klaviyo.com description: Production security: - Klaviyo-API-Key: [] tags: - name: Conversations description: conversations paths: /api/conversation-messages: post: operationId: create_conversation_message summary: Create Conversation Message description: 'Send an outbound message to a conversation. Requires OAuth authentication and account-level enablement. To request access, reach out in the [developer community](https://community.klaviyo.com/groups/developer-group-64).

*Rate limits*:
Burst: `3/s`
Steady: `60/m` **Scopes:** `conversations:write`' parameters: - name: revision in: header description: 'API endpoint revision (format: YYYY-MM-DD[.suffix])' required: true schema: type: string default: '2026-04-15' requestBody: description: Create a conversation message required: true content: application/vnd.api+json: schema: $ref: '#/components/schemas/ConversationMessageCreateQuery' responses: '202': description: Success 4XX: $ref: '#/components/responses/ClientError' 5XX: $ref: '#/components/responses/ServerError' tags: - Conversations x-klaviyo-pre-release: None x-klaviyo-ratelimit: burst: 3/s steady: 60/m x-klaviyo-scopes: - conversations:write components: schemas: ConversationMessageCreateQuery: type: object properties: data: $ref: '#/components/schemas/ConversationMessageCreateQueryResourceObject' required: - data ConversationMessageCreateQueryResourceObject: type: object properties: type: $ref: '#/components/schemas/ConversationMessageEnum' attributes: type: object properties: body: type: string required: - body relationships: type: object properties: conversation: type: object properties: data: type: object properties: type: $ref: '#/components/schemas/ConversationEnum' id: description: Related Conversation type: string required: - type - id required: - conversation required: - type - attributes - relationships ConversationEnum: type: string enum: - conversation ConversationMessageEnum: type: string enum: - conversation-message responses: ClientError: description: Client Error content: application/vnd.api+json: schema: type: object properties: errors: type: array items: type: object required: - id - code - title - detail properties: id: type: string code: type: string title: type: string detail: type: string source: type: object properties: pointer: type: string parameter: type: string required: - errors ServerError: description: Server Error content: application/vnd.api+json: schema: type: object properties: errors: type: array items: type: object required: - id - code - title - detail properties: id: type: string code: type: string title: type: string detail: type: string source: type: object properties: pointer: type: string parameter: type: string required: - errors securitySchemes: Klaviyo-API-Key: type: apiKey in: header name: Authorization description: Private key authentication for /api/ endpoints is performed by setting the `Authorization` header to `Klaviyo-API-Key your-private-api-key`
For more information please visit https://developers.klaviyo.com/en/v2026-04-15/reference/api-overview#authentication x-default: Klaviyo-API-Key your-private-api-key x-readme: explorer-enabled: false proxy-enabled: true samples-enabled: true