{
"openapi": "3.0.2",
"info": {
"title": "Klaviyo API (Beta)",
"version": "2026-10-15.pre",
"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/brand-fonts/{id}": {
"patch": {
"operationId": "update_brand_font_beta",
"summary": "Update Brand Font",
"description": "\n > \ud83d\udea7 This endpoint is in beta and subject to change.\n >\n > A beta revision header (2026-10-15.pre) is required to use our beta APIs. Klaviyo APIs in beta are not intended for use in production. See our [versioning and deprecation policy](https://developers.klaviyo.com/en/docs/api_versioning_and_deprecation_policy) for more information.\n\nUpdate a Google or web-safe font in the brand font library.\n\nUploaded and Adobe fonts cannot be updated through this API.
*Rate limits*:
Burst: `3/s`
Steady: `60/m`\n\n**Scopes:**\n`brands:write`\n\n[OpenAPI Spec](https://raw.githubusercontent.com/klaviyo/openapi/main/openapi/beta/apis/update_brand_font_beta.json)",
"parameters": [
{
"name": "id",
"in": "path",
"description": "The ID of the brand font.",
"required": true,
"schema": {
"description": "The ID of the brand font.",
"type": "string",
"example": "google:42"
}
},
{
"name": "fields[brand-font]",
"in": "query",
"description": "For more information please visit https://developers.klaviyo.com/en/v2026-10-15.pre/reference/api-overview#sparse-fieldsets",
"required": false,
"schema": {
"type": "array",
"items": {
"type": "string",
"enum": [
"fallback",
"family",
"font_family",
"font_type",
"id",
"name",
"variants"
]
}
},
"explode": false
},
{
"name": "revision",
"in": "header",
"description": "API endpoint revision (format: YYYY-MM-DD[.suffix])",
"required": true,
"schema": {
"type": "string",
"default": "2026-10-15.pre"
}
}
],
"requestBody": {
"required": true,
"content": {
"application/vnd.api+json": {
"schema": {
"$ref": "#/components/schemas/BrandFontPartialUpdateQuery"
}
}
}
},
"responses": {
"200": {
"description": "Success",
"content": {
"application/vnd.api+json": {
"schema": {
"$ref": "#/components/schemas/PatchBrandFontResponse"
}
}
}
},
"4XX": {
"$ref": "#/components/responses/ClientError"
},
"5XX": {
"$ref": "#/components/responses/ServerError"
}
},
"tags": [
"Beta APIs"
],
"x-klaviyo-pre-release": "BETA",
"x-klaviyo-ratelimit": {
"burst": "3/s",
"steady": "60/m"
},
"x-klaviyo-scopes": [
"brands:write"
],
"x-klaviyo-subtag": "Brands"
}
}
},
"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": {
"AgentHints": {
"description": "Optional hints emitted by the API for agent callers",
"type": "object",
"properties": {
"next_steps": {
"description": "Suggested follow-up actions for agents to take after this response",
"type": "array",
"items": {
"type": "string"
}
}
}
},
"BrandFontEnum": {
"type": "string",
"enum": [
"brand-font"
]
},
"BrandFontPartialUpdateQuery": {
"type": "object",
"properties": {
"data": {
"$ref": "#/components/schemas/BrandFontPartialUpdateQueryResourceObject"
}
},
"required": [
"data"
]
},
"BrandFontPartialUpdateQueryResourceObject": {
"type": "object",
"properties": {
"type": {
"$ref": "#/components/schemas/BrandFontEnum"
},
"id": {
"description": "The ID of the brand font.",
"type": "string",
"example": "google:42"
},
"attributes": {
"type": "object",
"properties": {
"name": {
"description": "Human-readable name for this font. Cannot be null.",
"type": "string",
"example": "Headings",
"nullable": true
},
"variants": {
"description": "The Google font variants, replacing the current ones. Google fonts only; cannot be null or empty.",
"type": "array",
"items": {
"$ref": "#/components/schemas/BrandFontVariant"
},
"nullable": true
},
"fallback": {
"description": "The web-safe fallback font. Google fonts only; cannot be null.",
"type": "string",
"example": "helvetica",
"enum": [
"arial",
"arial-black",
"century-gothic",
"comic-sans",
"courier",
"courier-new",
"geneva",
"georgia",
"helvetica",
"lucida",
"lucida-grande",
"lucida-sans",
"ms-serif",
"new-york",
"palatino",
"palatino-linotype",
"tahoma",
"times-new-roman",
"trebuchet-ms",
"verdana"
],
"nullable": true
}
}
}
},
"required": [
"type",
"id",
"attributes"
]
},
"BrandFontVariant": {
"type": "object",
"properties": {
"weight": {
"description": "The font weight.",
"type": "integer",
"example": 400,
"enum": [
100,
200,
300,
400,
500,
600,
700,
800,
900
]
},
"style": {
"description": "The font style.",
"type": "string",
"example": "normal",
"enum": [
"italic",
"normal"
]
}
},
"required": [
"weight",
"style"
]
},
"ObjectLinks": {
"type": "object",
"properties": {
"self": {
"type": "string",
"format": "uri"
}
},
"required": [
"self"
]
},
"PatchBrandFontResponse": {
"type": "object",
"properties": {
"data": {
"type": "object",
"properties": {
"type": {
"$ref": "#/components/schemas/BrandFontEnum"
},
"id": {
"description": "The ID of the brand font.",
"type": "string",
"example": "google:42"
},
"attributes": {
"type": "object",
"properties": {
"font_type": {
"description": "The kind of font.",
"type": "string",
"example": "google",
"enum": [
"custom",
"google",
"typekit",
"websafe"
]
},
"family": {
"description": "The font family name.",
"type": "string",
"example": "Barlow Condensed"
},
"name": {
"description": "Human-readable name for this font.",
"type": "string",
"example": "Barlow Condensed"
},
"font_family": {
"description": "The CSS font-family value to set as `font_family` in brand text styles to use this font.",
"type": "string",
"example": "'Barlow Condensed', Helvetica, Arial, sans-serif"
},
"fallback": {
"description": "The web-safe font used while this font loads or where it is unsupported. Null for web-safe fonts.",
"type": "string",
"example": "helvetica",
"enum": [
"arial",
"arial-black",
"century-gothic",
"comic-sans",
"courier",
"courier-new",
"geneva",
"georgia",
"helvetica",
"lucida",
"lucida-grande",
"lucida-sans",
"ms-serif",
"new-york",
"palatino",
"palatino-linotype",
"tahoma",
"times-new-roman",
"trebuchet-ms",
"verdana"
],
"nullable": true
},
"variants": {
"description": "The weights and styles available for this font. Null for fonts without individually selectable variants.",
"type": "array",
"items": {
"$ref": "#/components/schemas/BrandFontVariant"
},
"nullable": true
}
},
"required": [
"font_type",
"family",
"name",
"font_family"
]
},
"links": {
"$ref": "#/components/schemas/ObjectLinks"
}
},
"required": [
"type",
"id",
"attributes",
"links"
]
},
"links": {
"$ref": "#/components/schemas/ObjectLinks"
},
"meta": {
"$ref": "#/components/schemas/ResponseMeta"
}
},
"required": [
"data"
]
},
"ResponseMeta": {
"description": "Response-level metadata",
"type": "object",
"properties": {
"agent_hints": {
"$ref": "#/components/schemas/AgentHints"
}
}
}
},
"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/v2026-10-15.pre/reference/api-overview#authentication",
"x-default": "Klaviyo-API-Key your-private-api-key"
}
}
},
"tags": [
{
"name": "Beta APIs",
"description": "beta apis"
}
]
}