{
"openapi": "3.0.2",
"info": {
"title": "Klaviyo API",
"version": "2026-07-15",
"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": []
}
],
"paths": {
"/api/conversation-messages": {
"post": {
"operationId": "create_conversation_message",
"summary": "Create Conversation Message",
"description": "Send an outbound message to a conversation.\n\nRequires 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`\n\n**Scopes:**\n`conversations:write`\n\n[OpenAPI Spec](https://raw.githubusercontent.com/klaviyo/openapi/main/openapi/stable/apis/create_conversation_message.json)",
"parameters": [
{
"name": "revision",
"in": "header",
"description": "API endpoint revision (format: YYYY-MM-DD[.suffix])",
"required": true,
"schema": {
"type": "string",
"default": "2026-07-15"
}
}
],
"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": {
"$ref": "#/components/responses/ServerError"
}
},
"tags": [
"Conversations"
],
"x-klaviyo-pre-release": "None",
"x-klaviyo-ratelimit": {
"burst": "3/s",
"steady": "60/m"
},
"x-klaviyo-scopes": [
"conversations:write"
]
}
}
},
"components": {
"responses": {
"ClientError": {
"description": "Client Error",
"content": {
"application/vnd.api+json": {
"schema": {
"type": "object",
"properties": {
"errors": {
"type": "array",
"items": {
"type": "object",
"required": [
"id",
"code",
"title",
"detail"
],
"properties": {
"id": {
"type": "string"
},
"code": {
"type": "string"
},
"title": {
"type": "string"
},
"detail": {
"type": "string"
},
"source": {
"type": "object",
"properties": {
"pointer": {
"type": "string"
},
"parameter": {
"type": "string"
}
}
}
}
}
}
},
"required": [
"errors"
]
}
}
}
},
"ServerError": {
"description": "Server Error",
"content": {
"application/vnd.api+json": {
"schema": {
"type": "object",
"properties": {
"errors": {
"type": "array",
"items": {
"type": "object",
"required": [
"id",
"code",
"title",
"detail"
],
"properties": {
"id": {
"type": "string"
},
"code": {
"type": "string"
},
"title": {
"type": "string"
},
"detail": {
"type": "string"
},
"source": {
"type": "object",
"properties": {
"pointer": {
"type": "string"
},
"parameter": {
"type": "string"
}
}
}
}
}
}
},
"required": [
"errors"
]
}
}
}
}
},
"schemas": {
"ConversationEnum": {
"type": "string",
"enum": [
"conversation"
]
},
"ConversationMessageCreateQuery": {
"type": "object",
"properties": {
"data": {
"$ref": "#/components/schemas/ConversationMessageCreateQueryResourceObject"
}
},
"required": [
"data"
]
},
"ConversationMessageCreateQueryResourceObject": {
"type": "object",
"properties": {
"type": {
"$ref": "#/components/schemas/ConversationMessageEnum"
},
"attributes": {
"type": "object",
"properties": {
"body": {
"type": "string"
},
"message_hierarchy": {
"description": "An ordered RCS and SMS pair to send instead of a plain SMS: the RCS content first, then the SMS fallback delivered when RCS cannot be sent.",
"type": "array",
"items": {
"oneOf": [
{
"$ref": "#/components/schemas/MessageHierarchyRcsItem"
},
{
"$ref": "#/components/schemas/MessageHierarchySmsItem"
}
]
},
"nullable": true
}
},
"required": [
"body"
]
},
"relationships": {
"type": "object",
"properties": {
"conversation": {
"type": "object",
"properties": {
"data": {
"type": "object",
"properties": {
"type": {
"$ref": "#/components/schemas/ConversationEnum"
},
"id": {
"description": "Related Conversation",
"type": "string"
}
},
"required": [
"type",
"id"
]
}
}
}
},
"required": [
"conversation"
]
}
},
"required": [
"type",
"attributes",
"relationships"
]
},
"ConversationMessageEnum": {
"type": "string",
"enum": [
"conversation-message"
]
},
"DynamicSMSImage": {
"type": "object",
"properties": {
"dynamic": {
"type": "boolean",
"example": true,
"default": true,
"enum": [
true
]
},
"dynamic_image_template": {
"description": "Dynamic image template URL (e.g., {{product.image_url}}).",
"type": "string"
}
},
"required": [
"dynamic_image_template"
]
},
"ImageAsset": {
"type": "object",
"properties": {
"id": {
"description": "The unique identifier for this image asset. Not allowed on update.",
"type": "integer"
},
"file_path": {
"description": "The file path of the image in Klaviyo's storage.",
"type": "string",
"example": "images/aa1ee5c1-039e-4d20-9e98-345755214556.jpeg"
},
"name": {
"description": "The human-readable name of the image.",
"type": "string",
"example": "product-image"
},
"format": {
"description": "The image file format.",
"type": "string",
"enum": [
"gif",
"jpeg",
"jpg",
"png",
"webp"
]
},
"file_size": {
"description": "The size of the image file in bytes.",
"type": "integer"
},
"updated": {
"description": "Timestamp when the image was last updated.",
"type": "string",
"format": "date-time",
"example": "2022-11-08T00:00:00+00:00"
},
"origin": {
"description": "The origin/source of the image (e.g., UI, API, AI, etc.).",
"type": "string",
"enum": [
"ADOPTION_SMS_FORM_FROM_EMAIL_FORM",
"ADOPTION_SMS_MULTI_STEP_FORM_FROM_EMAIL_FORM",
"AI",
"API",
"APPLICATION",
"CLONED",
"COMPOSER",
"COMPOSER_AI_EDITED",
"COMPOSER_AI_GENERATED",
"COMPOSER_USED_IN_KLAVIYO_OBJECT",
"COMPOSER_USER_UPLOADED",
"COMPOSER_WEB_SCRAPED",
"INTEGRATION",
"KLAVIYO",
"LIBRARY",
"MARKETING_AGENT",
"SOCIAL_INSTAGRAM",
"SOCIAL_INSTAGRAM_OVERLAID",
"UI",
"WEB_SCRAPE"
],
"nullable": true
},
"url": {
"description": "The full URL to access the image.",
"type": "string",
"example": "https://d3k81ch9hvuctc.cloudfront.net/company/RyGRiN/images/aa1ee5c1-039e-4d20-9e98-345755214556.jpeg"
},
"image_type": {
"description": "The type of image (static or dynamic).",
"type": "string",
"enum": [
"dynamic",
"static"
]
},
"l10n_key": {
"description": "Localization key for this image asset, if applicable.",
"type": "string",
"example": "sms::01KAPBZTQBAJFD5RG9NYXBWHMR::mms_static_image_asset_id",
"nullable": true
}
},
"required": [
"id",
"file_path",
"name",
"format",
"file_size",
"updated",
"url",
"image_type"
]
},
"MediaAsset": {
"type": "object",
"properties": {
"id": {
"description": "The unique identifier for this media asset. Not allowed on update.",
"type": "string"
},
"company_id": {
"description": "The company ID that owns this media.",
"type": "string",
"example": "RyGRiN"
},
"url": {
"description": "The full URL to access the media.",
"type": "string",
"example": "https://d3k81ch9hvuctc.cloudfront.net/company/RyGRiN/videos/01KG5BPQBSY8F12ZWTGYHPPRXC.mp4"
},
"media_type": {
"description": "The media type (e.g., 'video' for video assets).",
"type": "string",
"example": "video",
"default": "video"
},
"name": {
"description": "The human-readable name of the media.",
"type": "string",
"example": "demo video.1"
},
"file_size": {
"description": "The size of the media file in bytes.",
"type": "integer"
},
"thumbnail_url": {
"description": "Optional thumbnail URL for video previews in RCS cards.",
"type": "string",
"nullable": true
},
"l10n_key": {
"description": "Localization key for this media asset, if applicable.",
"type": "string",
"nullable": true
}
},
"required": [
"id",
"company_id",
"url",
"name",
"file_size"
]
},
"MediaAssetReference": {
"type": "object",
"properties": {
"static_asset_id": {
"description": "Reference to a static media asset.",
"type": "string",
"nullable": true
},
"dynamic_template": {
"description": "Dynamic template (e.g. Django tags) resolving to the media URL.",
"type": "string",
"nullable": true
},
"thumbnail": {
"description": "Optional thumbnail image reference for video media.",
"$ref": "#/components/schemas/SlimImageReference",
"nullable": true
}
}
},
"MessageHierarchyRcsItem": {
"type": "object",
"properties": {
"message": {
"description": "The plain text message content. Often empty for RCS when rich_content is used.",
"type": "string",
"default": ""
},
"message_format": {
"description": "The format of this message (always 'RCS' for RCS entries).",
"type": "string",
"example": "RCS",
"default": "RCS",
"enum": [
"RCS"
]
},
"rich_content": {
"description": "Rich content for RCS messages (cards, suggestions, etc.).",
"$ref": "#/components/schemas/RCSRichContent",
"nullable": true
},
"extra": {
"description": "Additional metadata for RCS messages. Legacy placement. This is typically used in rich_content.cards.extra.",
"type": "object",
"nullable": true
},
"image": {
"description": "Legacy top-level image reference on the RCS hierarchy row (MySQL-backed). Prefer rich_content for RCS media going forward.",
"$ref": "#/components/schemas/SlimImageReference",
"nullable": true
}
}
},
"MessageHierarchySmsItem": {
"type": "object",
"properties": {
"message": {
"description": "The plain text SMS message content.",
"type": "string",
"example": "Check out our latest deals: https://example.com"
},
"message_format": {
"description": "The format of this message (always 'SMS' for SMS entries).",
"type": "string",
"example": "SMS",
"default": "SMS",
"enum": [
"SMS"
]
},
"extra": {
"description": "Additional metadata for SMS messages (e.g., should_use_same_content flag).",
"type": "object",
"nullable": true
},
"image": {
"description": "Image reference for MMS messages. Mutually exclusive with media.",
"nullable": true,
"oneOf": [
{
"$ref": "#/components/schemas/StaticSMSImage"
},
{
"$ref": "#/components/schemas/DynamicSMSImage"
}
]
},
"media": {
"description": "Video media for MMS messages as either a hydrated MediaAsset or a reference-style payload. Mutually exclusive with image.",
"nullable": true,
"oneOf": [
{
"$ref": "#/components/schemas/MediaAsset"
},
{
"$ref": "#/components/schemas/MediaAssetReference"
}
]
}
},
"required": [
"message"
]
},
"RCSCard": {
"type": "object",
"properties": {
"id": {
"description": "Unique identifier for this card.",
"type": "string",
"example": "44214e8f-a2fb-43b1-a8e1-1170715ffcfa"
},
"title": {
"description": "Optional title for the card. 200 characters is the rendered-length budget; the stored value may be longer because it is template-evaluated before it reaches the carrier.",
"type": "string",
"example": "Special Offer",
"nullable": true
},
"text": {
"description": "The text content/description of the card. 2000 characters is the rendered-length budget; the stored value may be longer because it is template-evaluated before it reaches the carrier.",
"type": "string",
"example": "Check out our new collection!",
"nullable": true
},
"extra": {
"description": "Additional card-specific metadata (e.g., product info). Optional.",
"type": "object",
"nullable": true
},
"image": {
"description": "Optional image for this card.",
"nullable": true,
"oneOf": [
{
"$ref": "#/components/schemas/ImageAsset"
},
{
"$ref": "#/components/schemas/SlimImageReference"
}
]
},
"video": {
"description": "Optional video for this card. May be a hydrated MediaAsset or a reference-style payload (e.g. static_asset_id), matching MMS ``MessageHierarchySmsItem.media`` behavior.",
"nullable": true,
"oneOf": [
{
"$ref": "#/components/schemas/MediaAsset"
},
{
"$ref": "#/components/schemas/MediaAssetReference"
}
]
},
"buttons": {
"description": "Optional action buttons for this card. At most 4.",
"type": "array",
"items": {
"$ref": "#/components/schemas/RCSSuggestion"
},
"nullable": true
}
},
"required": [
"id"
]
},
"RCSRichContent": {
"type": "object",
"properties": {
"cards": {
"description": "List of cards in this rich content. At most 10.",
"type": "array",
"items": {
"$ref": "#/components/schemas/RCSCard"
},
"nullable": true
},
"suggestions": {
"description": "List of suggestion buttons for user interaction. At most 11.",
"type": "array",
"items": {
"$ref": "#/components/schemas/RCSSuggestion"
},
"nullable": true
},
"file": {
"description": "Standalone media file for RCS messages without cards.",
"$ref": "#/components/schemas/MediaAssetReference",
"nullable": true
}
}
},
"RCSSuggestion": {
"type": "object",
"properties": {
"id": {
"description": "Unique identifier for this suggestion/button.",
"type": "string",
"example": "quick-action-1767105662671"
},
"text": {
"description": "The display text for the suggestion button. 25 characters is the rendered-length budget; the stored value may be longer because it is template-evaluated before it reaches the carrier.",
"type": "string",
"example": "Shop Now"
},
"type": {
"description": "The type of action this suggestion performs.",
"type": "string",
"enum": [
"OPEN_URL",
"REPLY"
]
},
"url": {
"description": "The URL to open (required for OPEN_URL type).",
"type": "string",
"example": "https://www.example.com/shop",
"nullable": true
},
"open_mode": {
"description": "How the URL opens on the device for OPEN_URL suggestions (browser vs webview size). Emitted to Infobip as openIn. Absent means browser.",
"type": "string",
"example": "WEBVIEW_FULL",
"enum": [
"BROWSER",
"WEBVIEW_FULL",
"WEBVIEW_HALF",
"WEBVIEW_TALL"
],
"nullable": true
}
},
"required": [
"id",
"text",
"type"
]
},
"SlimImageReference": {
"type": "object",
"properties": {
"static_image_asset_id": {
"description": "ID of the static image asset when the card uses a library image.",
"type": "integer",
"nullable": true
},
"dynamic_image_template": {
"description": "Dynamic image template (e.g. Django tags) for the card image.",
"type": "string",
"nullable": true
},
"rendered_asset_url": {
"description": "Pre-rendered image URL when available.",
"type": "string",
"nullable": true
}
}
},
"StaticSMSImage": {
"type": "object",
"properties": {
"dynamic": {
"type": "boolean",
"default": false,
"enum": [
false
],
"nullable": true
},
"static_image_asset_id": {
"description": "The ID of the static image asset to include.",
"type": "integer"
}
},
"required": [
"static_image_asset_id"
]
}
},
"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/v2026-07-15/reference/api-overview#authentication",
"x-default": "Klaviyo-API-Key your-private-api-key"
}
}
},
"tags": [
{
"name": "Conversations",
"description": "conversations"
}
]
}