Klaviyo Custom Objects API
custom objects
Klaviyo Custom Objects 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 Custom Objects. 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 6 operations across 4 paths, and defines 17 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 Custom Objects 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 6
Across 4 paths, the API surfaces 6 operations — 1 DELETE, 2 GET, 3 POST. Each is listed below with its method, path, parameters, and response codes.
custom objects
Schemas 17
The contract defines 17 schemas that model the data the API accepts and returns. The most detailed are CollectionLinks (5 properties), DataSourceResponseObjectResource (4 properties), DataSourceRecordCreateJobCreateQueryResourceObject (3 properties), DataSourceRecordBulkCreateJobCreateQueryResourceObject (3 properties). Each schema is shown below with its type and property counts.
Specification
The full machine-readable OpenAPI contract behind this narrative.
Source
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