Customer.io Segments API

Create and manage manual segments, and retrieve segment membership information.

Business capability
Customer Segmentation Management BC-420.20

Operations 7

POST /v1/segments Create a manual segment #
GET /v1/segments List segments #
GET /v1/segments/{segment_id} Get a segment #
DELETE /v1/segments/{segment_id} Delete a segment #
GET /v1/segments/{segment_id}/used_by Get a segment's dependencies #
GET /v1/segments/{segment_id}/customer_count Get a segment customer count #
GET /v1/segments/{segment_id}/membership List customers in a segment #

Work with this as data

Every API here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for apis

7 MCP tools reach this
  • find_apisBrowse and filter every API in the catalog.
  • get_api_artifactsOne API's artifacts, grouped by type.
  • get_openapiThe primary OpenAPI for this API.
  • find_similar_apisAPIs that look like this one.
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools →

Call it yourself

curl for this page
This API
curl "https://apis.io/api/v1/apis/customer-io-segments-api"
All apis
curl "https://apis.io/api/v1/apis?limit=25"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

A second provider on the same verified email joins the account you already have.

OpenAPI Specification

customer-io-segments-api-openapi.yml Raw ↑
openapi: 3.2.0
info:
  version: 1.0.0
  title: Customer.io App Segments API
  description: Our App API provides ways to trigger messages and retrieve information about people, campaigns, broadcasts, and more.
servers:
- url: https://api.customer.io
  description: The base URL for broadcasts, transactional messages, and data-retrieval APIs. These endpoints use bearer authorization, and require a [token that you generate in the UI](https://fly.customer.io/settings/api_credentials?keyType=app).
- url: https://api-eu.customer.io
  description: The base URL for broadcasts, transactional messages, and data-retrieval APIs (EU region). These endpoints use bearer authorization, and require a [token that you generate in the UI](https://fly.customer.io/settings/api_credentials?keyType=app).
tags:


# --- truncated at 32 KB (42 KB total) ---
# Full source: https://raw.githubusercontent.com/api-evangelist/customer-io/refs/heads/main/openapi/customer-io-segments-api-openapi.yml