Customer.io
Customer.io is a customer engagement platform that combines a customer data platform, marketing automation, and messaging delivery to send behavior-triggered email, push, SMS, and in-app messages. Its API surface includes the Track API for sending behavioral data and customer profile updates, the App API for managing workspace resources and sending transactional and broadcast messages, the Pipelines API which is a Segment-spec data ingestion interface, and outbound reporting webhooks that deliver message lifecycle events.
Reference-quality API operations across every facet — a rich contract, published governance, transparent operations, and machine-readable commercial terms.
API Evangelist profiles Customer.io the way a machine reads it — 87 machine-readable artifacts across 4 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Customer.io scores 89.3/100 (exemplar), with a separate agent-readiness read of 55/100 (agent ready). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance. Every facet and dimension name is a link: it opens that measurement's page on APIs.io, where the rating runs across the whole catalog — the exact checks that feed it, how every profiled provider distributes on it, and who is at the top of it.
Kin Score
How this is scored →scored 2026-09-08 · rubric v0.20.0
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How we profile Customer.io
Each block below is one kind of artifact we hold for Customer.io. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 42
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
Customer.io Track API
The Customer.io Track API allows developers to send behavioral data and customer profile information into Customer.io. It provides endpoints for identifying customers, tracking ...
Customer.io Activities API
Retrieve activity logs for your workspace.
Customer.io Alias API
Merge two user identities by creating an alias linking a new identity to an existing one.
Customer.io Batch API
Send multiple API calls in a single request for improved performance.
Customer.io Broadcasts API
Trigger API-triggered broadcasts to send messages to groups of people based on segments or filters.
Customer.io Campaigns API
Retrieve information about campaigns, campaign actions, and campaign metrics in your workspace.
Customer.io Collections API
Manage collections of data used in message personalization.
Customer.io Customers API
Look up customer profiles, search for customers, and retrieve customer attributes and activity data.
Customer.io Exports API
Export customer data, deliveries, and other information from your workspace.
Customer.io Group API
Associate people with groups or organizations.
Customer.io Identify API
Identify people and set their profile attributes. The identify call tells Customer.io who the current user is and assigns traits to them.
Customer.io Messages API
Retrieve information about individual messages sent to customers.
Customer.io Newsletters API
Retrieve information about newsletters and newsletter variants.
Customer.io Page API
Record page views from web applications.
Customer.io Screen API
Record screen views from mobile applications.
Customer.io Segments API
Create and manage manual segments, and retrieve segment membership information.
Customer.io Sender Identities API
Manage sender identities used for sending messages.
Customer.io Snippets API
Manage reusable content snippets for use in messages.
Customer.io Transactional API
Send transactional messages such as password resets, purchase receipts, and other important notifications triggered by user actions.
Customer.io MCP
Customer.io's first-party hosted Model Context Protocol server. It exposes the full Journeys App API and CDP Data Pipelines API to any MCP client through eight tools — a context...
Customer.io Assets API
Manage file assets such as images and PDFs and organize them into folders.
Customer.io Customer.io App API
The Customer.io App API API from Customer.io — 0 operation(s) for customer.io app api.
Customer.io Data Index API
Update descriptions for attributes and events in your workspace. This helps improve AI-generated content and segments.
Customer.io Design Studio API
Use these endpoints to manage emails, translations, and components made with Design Studio. You can programmatically manage Design Studio content and migrate templates from an e...
Customer.io ESP Suppression API
If you use Customer.io as your email service provider (ESP), these endpoints help you retrieve information about email addresses suppressed directly by the ESP. ESP-based suppre...
Customer.io Forms API
Connect forms to your workspace to identify people, apply form responses to people, and trigger campaigns for people who fill out forms on your website or in your app.
Customer.io Imports API
APIs to upload CSV files containing lists of people. These endpoints provide a convenient way to add and update people without having to make an `identify` call for each individ...
Customer.io Info API
Returns the list of addresses used by Customer.io. You must add add these addresses to your allowlist when using a custom SMTP provider and blocking unknown IP addresses.
Customer.io Live Notifications API
Start, update, and end live notifications—real-time activities on the iOS Lock Screen and Dynamic Island, and in the Android notification shade. Your server drives the activity'...
Customer.io Newsletter Metrics API
Newsletter metrics include metrics for translations, A/B tests, and links. These endpoints return information about newsletter metrics including metrics for translations and A/B...
Customer.io Newsletter Variants API
A newsletter variant is a translation or an A/B test. You can create, update, or delete variants in newsletters from these endpoints. You can also create a new A/B test group. I...
Customer.io Objects API
Objects are "groups" that you can relate people to in Customer.io—like the companies they work for, the online classes they take, and so on. These APIs help you find objects, th...
Customer.io Opt Outs API
The Opt-outs API from Customer.io — 2 operation(s) for opt-outs.
Customer.io Reporting Webhooks API
Set up webhooks to inform an external service about Customer.io events. Webhooks can notify you immediately when immediately when customer attributes change or when people open ...
Customer.io Send Messages API
Use these endpoints to send broadcasts or transactional messages to your audience. They use the same authentication method, but review the limits for both types of workflows to ...
Customer.io Subscription Center API
A subscription center differentiates the types of messages available for your product. Your audience sets subscription preferences by name, but we record subscription preference...
Customer.io Track Customers API
Add, modify, suppress, or unsuppress people (referred to as "customers" in our APIs). You can also use these endpoints to set attributes on people.
Customer.io Track Events API
Use customer events to trigger campaigns or add users to segments. You can attribute events directly to customers or send anonymous events and associate them with users later wh...
Customer.io Track Segments API
Manual segments are lists of people that you incorporate using the API or by uploading CSVs. You can add people to, or remove people from, manual segments with these endpoints. ...
Customer.io Track V2 API
This version of our edge API has only two endpoints, but supports the majority of our traditional v1 track operations and then some based on the `type` and `action` keys that yo...
Customer.io Track Region API
Determine whether your account and data are hosted in the US or EU data center using your [Track API Key](https://fly.customer.io/settings/api_credentials).
Customer.io Workspaces API
An API to retrieve information about your workspaces in your account. You can use this to look up counts for messages sent, monthly billable emails sent, people, and objects.
Scroll within the panel for all 42 ·
Open Collections 26
Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
API Collection
OPEN COLLECTIONCustomer.io App Activities API
OPEN COLLECTIONCustomer.io App Activities Alias API
OPEN COLLECTIONCustomer.io App API
OPEN COLLECTIONCustomer.io App Activities Batch API
OPEN COLLECTIONCustomer.io App Activities Broadcasts API
OPEN COLLECTIONCustomer.io App Activities Campaigns API
OPEN COLLECTIONCustomer.io App Activities Collections API
OPEN COLLECTIONCustomer.io App Activities Customers API
OPEN COLLECTIONCustomer.io App Activities Devices API
OPEN COLLECTIONCustomer.io App Activities Entity API
OPEN COLLECTIONCustomer.io App Activities Events API
OPEN COLLECTIONCustomer.io App Activities Exports API
OPEN COLLECTIONCustomer.io App Activities Group API
OPEN COLLECTIONCustomer.io App Activities Identify API
OPEN COLLECTIONCustomer.io App Activities Merge API
OPEN COLLECTIONCustomer.io App Activities Messages API
OPEN COLLECTIONCustomer.io App Activities Newsletters API
OPEN COLLECTIONCustomer.io App Activities Page API
OPEN COLLECTIONCustomer.io Pipelines API
OPEN COLLECTIONCustomer.io App Activities Screen API
OPEN COLLECTIONCustomer.io App Activities Segments API
OPEN COLLECTIONCustomer.io App Activities Sender Identities API
OPEN COLLECTIONCustomer.io App Activities Snippets API
OPEN COLLECTIONCustomer.io App Activities Track API
OPEN COLLECTIONCustomer.io App Activities Transactional API
OPEN COLLECTIONScroll within the panel for all 26 ·
MCP Servers 1
Model Context Protocol servers expose these APIs directly to AI agents. We profile them because agent-native access is the fastest-growing way this provider's capabilities actually get used.
Model Context Protocol servers that expose these APIs to AI agents.
Customer.io MCP
Customer.io operates a first-party, hosted Model Context Protocol server that exposes the full Journeys App API and the CDP Data Pipelines API to any MCP client. It is a remote ...
MCP SERVERGraphQL 1
Where a provider ships GraphQL, the schema is the contract. We profile it alongside the REST surface so the whole interface is legible in one place.
GraphQL schemas published by this provider.
Customer.io GraphQL Schema
This conceptual GraphQL schema represents the Customer.io messaging and marketing automation platform. Customer.io provides APIs for tracking behavioral data, managing customer ...
GRAPHQLPricing Plans 1
Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the things the Kin Score reads for access clarity — renamed from commercial clarity in rubric 0.12, because a free statutory interface has access terms and no commercial ones.
Published pricing tiers and plan structures.
Rate Limits 1
Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.
Documented rate limits and quota policies.
Customer Io Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.
Cost, billing, and metering signals for API financial operations.
Customer Io Finops
FINOPSEvent Specifications 1
Not every API is request/response. AsyncAPI describes the event-driven and streaming side — the webhooks and channels — so the asynchronous half of the interface is documented the same way the synchronous half is.
AsyncAPI definitions for this provider's event-driven and streaming APIs.
Customer.io Reporting Webhooks
Customer.io Reporting Webhooks send real-time message activity events as JSON payloads via HTTP POST to a configured endpoint. These events include message sends, deliveries, op...
ASYNCAPISemantic Vocabularies 1
JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.
JSON-LD contexts and semantic vocabularies used across these APIs.
Customer Io Context
JSON-LDSpectral Rules 3
Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.
JSON Schema 3
Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.
Standalone JSON Schema definitions for this provider's data models.
Customer.io Customer
JSON SCHEMACustomer.io Event
JSON SCHEMACustomer.io Reporting Webhook Payload
JSON SCHEMASecurity Posture 4
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Scopes 1
OAuth scopes are the vocabulary of least-privilege access. Profiling them shows exactly what an integration — or an agent acting on a user's behalf — is allowed to do.
OAuth scopes governing access to this provider's APIs.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Resources
Every other property we hold for Customer.io — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Get Started 5
Portal, sign-up, and the first successful call
Documentation 6
Reference material describing how the API behaves
Agent Surfaces 6
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 9
Pagination, idempotency, versioning, errors, and events
Scroll within the panel for all 9 ·
Build 5
SDKs, sample code, and the tooling you integrate with
Access & Security 7
Authentication, authorization, and security posture
Scroll within the panel for all 7 ·
Learn 1
Tutorials, courses, talks, and written guidance
Operate 4
Status, limits, changes, and where to get help
Commercial 5
Pricing, plans, and the legal terms of use
Company 3
The organization behind the API
Other 6
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/customer-io · machine-readable index on apis.io
This is an independent, third-party profile of Customer.io, 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.
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