How AI is applied across API Evangelist and APIs.io. Read my AI disclosure →
API Evangelist API Evangelist
Discovery
Learnings
Guidance
Toolbox
Alignment
API Evangelist LLC
Discovery
Learnings
Guidance
Toolbox
Alignment
API Evangelist LLC

Need help?

Contact us
Customer.io

Customer.io Customers API

Look up customer profiles, search for customers, and retrieve customer attributes and activity data.

Documentation Provider Profile APIs.io OpenAPI GitHub

Customer.io Customers API is one of 42 APIs that Customer.io publishes on the APIs.io network, described by a machine-readable OpenAPI specification.

Tagged areas include Customers. The published artifact set on APIs.io includes an OpenAPI specification and API documentation.

This API exposes 9 operations across 8 paths. It is described by OpenAPI 3.2.0, at version 1.0.0.

Requests are made against 2 base URLs: https://api.customer.io, https://api-eu.customer.io.

9 operations 8 paths 0 schemas 7 GET2 POST

Metadata

The identity and technical contract details declared by the specification.

Specification
OpenAPI 3.2.0
API Version
1.0.0
Base URL
https://track.customer.io
Authentication
HTTP Bearer, HTTP Bearer, HTTP Bearer
Resource Areas
1

Authentication & Security 3

Customer.io Customers API declares 3 security schemes for authenticating requests. It accepts HTTP bearer tokens (Bearer-Auth). It accepts HTTP bearer tokens (sa_live_) (ServiceAccount-Auth). It accepts HTTP bearer tokens (bearerAuth).

  • Bearer-Auth — The App API uses a bearer authentication scheme. You can generate a bearer token, known as an App API Key, with a defined scope in [your account settings](http…
  • ServiceAccount-Auth — Transactional send endpoints (/v1/send/email, /v1/send/push, /v1/send/sms, /v1/send/inapp, /v1/send/inboxmessage) also accept a service-account bearer token, p…
  • bearerAuth — API key passed as a Bearer token

Paths & Operations 9

Across 8 paths, the API surfaces 9 operations — 7 GET, 2 POST. Each is listed below with its method, path, parameters, and response codes.

Customers 9

Find profiles (referred to as "customers" in our APIs), their attributes, the segments they belong to, etc. Use the track API to add profiles to your workspace and assign their at…

GET
/v1/customers
Get customers by email
getPeopleEmail 1 param → 200401429
POST
/v1/customers
Search for customers
getPeopleFilter 2 params body → 200401429
GET
/v1/customers/{customer_id}/attributes
Lookup a customer's attributes
getPersonAttributes 2 params → 200404429
GET
/v1/customers/{customer_id}/relationships
Lookup a customer's relationships
getPersonRelationships 4 params → 200404429
POST
/v1/customers/attributes
List customers, attributes, and devices
getPeopleById 1 param body → 200400429
GET
/v1/customers/{customer_id}/segments
Lookup a customer's segments
getPersonSegments 2 params → 200404429
GET
/v1/customers/{customer_id}/messages
Lookup messages sent to a customer
getPersonMessages 6 params → 200404429
GET
/v1/customers/{customer_id}/activities
Lookup a customer's activities
getPersonActivities 6 params → 200400404429
GET
/v1/customers/{customer_id}/subscription_preferences
Lookup a customer's subscription preferences
getPersonSubscriptionPreferences 4 params → 200400404429

Specification

The full machine-readable OpenAPI contract behind this narrative.

Source

customer-io-customers-api-openapi.yml Raw ↑

Other APIs Customer.io publishes across the network.

Customer.io Track API
AE Profile APIs.io
Customer.io Activities API
AE Profile APIs.io
Customer.io Alias API
AE Profile APIs.io
Customer.io Batch API
AE Profile APIs.io
Customer.io Broadcasts API
AE Profile APIs.io
Customer.io Campaigns API
AE Profile APIs.io
Customer.io Collections API
AE Profile APIs.io
Customer.io Exports API
AE Profile APIs.io
Customer.io Group API
AE Profile APIs.io
Customer.io Identify API
AE Profile APIs.io
Customer.io Messages API
AE Profile APIs.io
Customer.io Newsletters API
AE Profile APIs.io
#Customers
← Back to C APIs
API Details
ID
customer-io:customer-io-customers-api
Base URL
https://track.customer.io
Docs
https://docs.customer.io/integrations/api/track/
Provider
Customer.io
APIs.io →  GitHub →
Explore more
All APIs Providers APIs.io Network
Work with this as data

Every API here is available over the API and to AI agents over MCP. APIs is not yet its own endpoint on the v1 API. Reach this content through network search and the tag graph, or the MCP server below.

Installs https://mcp.apievangelist.com/mcp in Claude, Cursor, VS Code and the rest — one button, every client.

MCP tools for apis
4 tools reach this content
  • search_api_evangelistSearch every content type across the network at once.
  • find_relatedThe shared-tag relevance graph — what else covers this.
  • get_tagEverything one tag labels, across all content types.
  • guide_topicPRO — a curated bundle for a topic: area, guidance, rules, papers, stories, services.
All tools & prompts
Call it yourself
curl for this page
Search the network for this 
curl "https://api.apievangelist.com/v1/search?q=customer-io-customers-api&limit=10"
Everything under a tag 
curl "https://api.apievangelist.com/v1/tags/customer-io-customers-api"

Discovery needs no key. Full bodies and the synthesis endpoints are Pro.

Get an API key

Free tier, no email required. Sign in with whichever identity you already have.

GitHub Google LinkedIn

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

Where this information came from

This is an independent, third-party profile of Customer.io Customers API, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.

The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.

Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.

info@apievangelist.com · Read the full data-sourcing policy →
On a security or compliance team? Put security in the subject line and you will get a person, not a form — we will tell you exactly which public URLs this profile was built from.