Klaviyo Lists API is one of 23 APIs that Klaviyo publishes on the APIs.io network, described by a machine-readable OpenAPI specification and an AsyncAPI event-driven specification.
Tagged areas include Lists. The published artifact set on APIs.io includes an OpenAPI specification, API documentation, an AsyncAPI specification, an API reference, authentication docs, and rate-limit docs.
This API exposes 13 operations across 8 paths, and defines 49 schemas. It is described by OpenAPI 3.0.2, at version 2026-04-15.
Requests are made against a single base URL, https://a.klaviyo.com.
Metadata
The identity and technical contract details declared by the specification.
Authentication & Security 1
Klaviyo Lists API declares
1 security scheme
for authenticating requests.
An API key is passed in the header as Authorization (Klaviyo-API-Key).
By default, every request must be authenticated.
Klaviyo-API-Key— Private key authentication for /api/ endpoints is performed by setting the Authorization header to Klaviyo-API-Key your-private-api-key For more information pl…
Paths & Operations 13
Across 8 paths, the API surfaces 13 operations — 2 DELETE, 8 GET, 1 PATCH, 2 POST. Each is listed below with its method, path, parameters, and response codes.
lists
Schemas 49
The contract defines 49 schemas that model the data the API accepts and returns. The most detailed are EmailMarketing (10 properties), ProfileLocation (10 properties), PredictiveAnalytics (10 properties), WhatsappConversationalChannel (8 properties). Each schema is shown below with its type and property counts.
Specification
The full machine-readable OpenAPI contract behind this narrative.
Source
More from Klaviyo 12
Other APIs Klaviyo publishes across the network.