Customer.io Track API
Browse all Customer APIs★ Only Publicly Available OpenAPI DocumentMarketingMarketing Automationbasic8 EndpointsREST
For Agents
Identify customers, track attributed and anonymous events, register devices, and manage suppression for Customer.io's behavioural messaging platform.
Use for: Identify a customer with email and name after signup, Track a 'subscription_renewed' event on a known customer, Track an anonymous 'page_viewed' event before signup, Add a push device token to a customer profile
Not supported: Does not handle campaign creation, transactional email sending, or reporting — use for identifying customers, tracking events, registering devices, and managing suppression only.
Jentic publishes the only available OpenAPI specification for Customer.io Track API, keeping it validated and agent-ready. This focused Track API surface covers customer identification and lifecycle, event tracking (attributed and anonymous), device registration, and suppression management. It is the minimal ingestion layer for sending behavioural data into Customer.io to drive messaging campaigns. Authentication uses HTTP Basic with a site ID and tracking API key.
Install Jentic One Beta
Connect the Customer.io Track API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Customer.io Track API, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
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Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
Capabilities
What an agent can do with Customer.io Track API.
Identify and update customers by customer_id with traits via PUT /customers/{customer_id}
Track named events for an identified customer to drive campaign triggers
Track anonymous events that can later be tied to a customer when they identify
Register and remove customer devices to enable push notification delivery
Suppress and unsuppress customer profiles for compliance and unsubscribe handling
Use Cases
Patterns agents use Customer.io Track API for, with concrete tasks.
★ Server-Side Customer Tracking
Send identification and event data from a server-side application into Customer.io to power behavioural campaigns. Use PUT /customers/{customer_id} to upsert profiles and POST /customers/{customer_id}/events to record actions like 'order_completed'. Suitable for backend services that own the source of truth for user behaviour and want a minimal ingestion surface.
Call PUT /customers/{customer_id} with the user's email and signup_date, then POST /customers/{customer_id}/events with name='order_completed' and the order details
Anonymous to Identified Stitching
Capture pre-signup behaviour through POST /events with an anonymous_id, then identify the same user with PUT /customers/{customer_id} once they sign up so Customer.io can stitch the prior events to the new profile. Useful for funnel attribution and welcome sequences that reference pre-signup actions.
Call POST /events with anonymous_id and name='trial_video_watched' before signup, then PUT /customers/{customer_id} with the same anonymous_id at signup to stitch history
Push Notification Device Management
Register and rotate device tokens so Customer.io campaigns can deliver push notifications. Use PUT /customers/{customer_id}/devices to add or update a token and DELETE /customers/{customer_id}/devices/{device_id} to revoke it on logout or app uninstall.
Call PUT /customers/{customer_id}/devices with the FCM or APNs token after a user signs in on a new device
AI Agent Event Tracking via Jentic
An AI agent automating ingestion of customer signals uses Jentic to send identify and event payloads directly to Customer.io. The agent searches for 'track customer event', loads /customers/{customer_id}/events, supplies the event name, and posts it without bespoke integration code.
Use Jentic to search 'track customer event' and execute /customers/{customer_id}/events for each row of an enrichment job's output
Key Endpoints
8 endpoints — jentic publishes the only available openapi specification for customer.
METHOD
PATH
DESCRIPTION
PUT
/customers/{customer_id}
Identify or update a customer
DELETE
/customers/{customer_id}
Delete a customer profile
POST
/customers/{customer_id}/events
Track a customer event
POST
/events
Track an anonymous event
PUT
/customers/{customer_id}/devices
Register a customer device
POST
/customers/{customer_id}/suppress
Suppress a customer
PUT
/customers/{customer_id}
Identify or update a customer
DELETE
/customers/{customer_id}
Delete a customer profile
POST
/customers/{customer_id}/events
Track a customer event
POST
/events
Track an anonymous event
PUT
/customers/{customer_id}/devices
Register a customer device
POST
/customers/{customer_id}/suppress
Suppress a customer
Why Jentic?
Three things that make agents converge on Jentic-routed access.
Credential isolation
Customer.io site ID and tracking API key pairs are stored encrypted in the Jentic vault and combined into the Basic auth header at call time. The agent never sees the raw key.
Intent-based discovery
Agents search by intent (e.g. 'identify customer' or 'track customer event') and Jentic returns the matching Track API operation with its parameter schema.
Time to first call
Direct Track API integration: half a day for auth, event schema design, and device registration. Through Jentic: under 30 minutes — search, load, execute.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Customer.io Track API through Jentic.
Why is there no official OpenAPI spec for Customer.io Track API?
Customer.io does not publish a complete OpenAPI specification for this Track surface. Jentic generates and maintains this spec so that AI agents and developers can call Customer.io Track API via structured tooling. It is validated against the live API and kept up to date. Get started at https://app.jentic.com/sign-up.
What authentication does the Customer.io Track API use?
The API uses HTTP Basic with a workspace site ID as the username and a tracking API key as the password. Through Jentic both values are held in the encrypted vault and injected into the Authorization header at call time.
Can I track anonymous events with the Customer.io Track API?
Yes. Call POST /events with an anonymous_id and event name. When the user later identifies, Customer.io stitches the anonymous history to the identified profile.
What are the rate limits for the Customer.io Track API?
Track endpoints accept high throughput; specific limits depend on the Customer.io plan and are not encoded in the spec. Use the broader Customer.io batch API for bulk loads when ingesting large volumes.
How do I register a push device token through Jentic?
Run pip install jentic, search for 'add customer device', load PUT /customers/{customer_id}/devices, and execute it with the token and platform. Jentic posts the device registration so push campaigns can reach the user.
How do I delete a customer profile?
Call DELETE /customers/{customer_id} with the customer identifier. Customer.io removes the profile and halts all subsequent processing for that ID, suitable for honouring data deletion requests.
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