Customer.io Data Source

The Customer.io connector enables you to ingest data from your Customer.io workspace—including campaigns, newsletters, broadcasts, customer profiles, segments, activity logs, sent messages, and data collections. Follow the instructions below to create a new data flow that ingests data from a Customer.io source in Nexla.

Customer.io

Create a New Data Flow

1. To create a new data flow, navigate to the Integrate section, and click the New Data Flow button. Then, select the desired flow type from the list, and click the Create button.

2. Select the Customer.io connector tile from the list of available connectors. Then, select the credential that will be used to connect to the Customer.io workspace, and click Next; or, create a new Customer.io credential for use in this flow.

3. In Nexla, Customer.io data sources can be created using pre-built endpoint templates, which expedite source setup for common Customer.io App API endpoints. Each template is designed specifically for the corresponding Customer.io endpoint, making source configuration easy and efficient.
   • To configure this source using a template, follow the instructions in Configure Using a Template.

   Customer.io sources can also be configured manually, allowing you to ingest data from Customer.io endpoints not included in the pre-built templates or apply further customizations to exactly suit your needs.
   • To configure this source manually, follow the instructions in Configure Manually.

Configure Using a Template

Nexla provides pre-built templates that can be used to rapidly configure data sources to ingest data from common Customer.io App API endpoints. Each template is designed specifically for the corresponding Customer.io endpoint, making data source setup easy and efficient.

Endpoint Settings

• Select the endpoint from which this source will fetch data from the Endpoint pulldown menu. Available endpoint templates are listed in the expandable boxes below. Click on an endpoint to see more information about it and how to configure your data source for this endpoint.

List Campaigns

Returns a list of all campaigns in your Customer.io workspace. Use this endpoint to retrieve metadata for all automated campaigns—including their names, statuses, trigger types, and scheduling configurations. This is useful for auditing your campaign library, monitoring campaign states, or building reporting pipelines around your Customer.io campaign data.

• This endpoint retrieves all campaigns automatically with no additional parameters required. Simply select the List Campaigns template and proceed to endpoint testing to verify the response.
• Each record in the returned data represents a single campaign and includes fields such as campaign ID, name, status, trigger type, and creation timestamp.

The Customer.io App API returns campaigns from the workspace associated with your authenticated App API Key. For complete details on campaign fields and statuses, see the Customer.io App API Reference.

List Campaign Actions

Returns a list of all actions defined across campaigns in the workspace. Campaign actions represent the individual messages, delays, attribute updates, and other steps that make up a Customer.io campaign workflow. Use this endpoint to inventory all campaign actions for documentation, auditing, or cross-campaign reporting.

• This endpoint retrieves all campaign actions across the entire workspace automatically. No additional parameters are required—select the List Campaign Actions template and proceed to endpoint testing to verify the response.
• Each record represents a single campaign action and includes fields such as the action ID, action type (for example, email, SMS, webhook), the parent campaign ID, and the action's content configuration.

Campaign actions are the building blocks of Customer.io campaign workflows. Combining this endpoint with the List Campaigns endpoint lets you build a complete picture of your campaign structure.

Get Campaign

Retrieves the full detail record for a single campaign by its ID, including its status, schedule, trigger settings, and other configuration details. Use this endpoint when you need complete information about a specific campaign rather than a summary list of all campaigns.

• Enter the numeric ID of the campaign you want to retrieve in the Campaign ID field. Campaign IDs can be obtained in any of the following ways:

  • Use the List Campaigns endpoint in Nexla to retrieve all campaigns and their IDs from your workspace.
  • In Customer.io, open the campaign and find its numeric ID in the browser URL (for example, https://fly.customer.io/journeys/campaigns/{campaign_id}).
  • Navigate to the Customer.io App API reference and look up the campaign ID using the List Campaigns endpoint directly.

Campaign IDs are numeric identifiers unique to each campaign within your workspace. For full details on campaign response fields, see the Get a Campaign API reference.

List Broadcast Triggers

Returns the historical trigger records for a given API-triggered broadcast campaign. Each trigger record captures the details of a single broadcast firing, including the payload sent, the audience targeted, and the trigger timestamp. Use this endpoint to audit or analyze the history of API-triggered broadcast executions for a specific campaign.

• Enter the numeric ID of the API-triggered broadcast campaign whose trigger history you want to retrieve in the Broadcast Campaign ID field. You can find broadcast campaign IDs in the following ways:

  • Use the List Campaigns endpoint in Nexla and filter for campaigns with a trigger type of api.
  • In Customer.io, open the API-triggered broadcast campaign and find its numeric ID in the browser URL.
• Only campaigns configured as API-triggered broadcasts will have trigger history records. Standard event-triggered or scheduled campaigns are not supported by this endpoint.

API-triggered broadcasts allow you to fire a one-to-many message send on demand by calling the Customer.io App API with an audience payload. This endpoint provides an audit trail of all past firings for compliance, reporting, or debugging purposes.

List Customers

Returns a paginated list of people (customers) in the workspace. Use this endpoint to retrieve your Customer.io audience for analysis, synchronization with other systems, or building customer-level reporting pipelines.

• This endpoint retrieves all customers in the workspace automatically. No additional parameters are required—select the List Customers template and proceed to endpoint testing to verify the response.
• Each record represents a single person in your Customer.io workspace and includes customer attributes, identifiers, and segment membership information.

Customer.io refers to individuals in your workspace as "people" or "customers" interchangeably. This endpoint surfaces all people records visible to your App API Key, which includes all people in the authenticated workspace.

Get Customer

Retrieves the full profile of a single customer by their ID, including all attributes and segment memberships. Use this endpoint when you need complete profile data for a specific individual—for example, to reconcile or enrich records in an external system.

• Enter the Customer.io customer (person) ID in the Customer ID field. Customer IDs can be obtained in the following ways:

  • Use the List Customers endpoint in Nexla to retrieve all customers and their IDs from your workspace.
  • In Customer.io, open a person's profile and locate their ID in the browser URL or profile details panel.
• The response includes the full customer attribute set, segment memberships, and any associated identifiers (email, anonymous ID, etc.).

Customer IDs in Customer.io are the unique identifiers you assigned when creating or updating a person's profile—typically a user ID from your application. For additional details on the customer profile response structure, see the Get a Customer API reference.

List Newsletters

Returns a list of all newsletters in your Customer.io workspace. Newsletters in Customer.io are one-time broadcast messages sent to a defined audience. Use this endpoint to retrieve newsletter metadata for reporting, auditing, or synchronization with external platforms.

• This endpoint retrieves all newsletters automatically. No additional parameters are required—select the List Newsletters template and proceed to endpoint testing to verify the response.
• Each record represents a single newsletter and includes fields such as its name, status, audience configuration, and send or schedule timestamps.

In Customer.io, newsletters are a type of broadcast—one-time, single messages sent to a group of people. They differ from API-triggered broadcasts in that they target a pre-configured static or dynamic audience rather than a payload-specified audience.

List Segments

Returns a list of all segments defined in the workspace. Segments in Customer.io are groups of people that share common attributes or behaviors. Use this endpoint to retrieve segment metadata for auditing, reporting, or replicating your audience structure to external systems.

• This endpoint retrieves all segments automatically. No additional parameters are required—select the List Segments template and proceed to endpoint testing to verify the response.
• Each record represents a single segment and includes its name, ID, type (manual or automatic), and creation timestamp.

Customer.io supports both manual segments (a fixed list of people you add or remove manually) and automatic segments (dynamically updated based on attribute or behavior criteria). Both segment types are returned by this endpoint.

List Activities

Returns a list of activity log entries across campaigns and broadcasts in your workspace. Activity entries capture events such as message sends, webhook deliveries, and attribute changes. Use this endpoint to build audit logs, analyze message delivery patterns, or monitor campaign activity in near-real time.

• This endpoint retrieves all activity entries automatically. No additional parameters are required—select the List Activities template and proceed to endpoint testing to verify the response.
• Each record represents a single activity entry and includes the activity type, the associated campaign or broadcast, and the timestamp of the activity.

Activity records provide a workspace-wide log of Customer.io actions. For high-volume workspaces, consider using Nexla's scheduling and incremental run features to capture only the most recent activity records in each data flow run.

List Messages

Returns a list of sent messages with delivery and engagement metadata, including opens, clicks, and bounces. Use this endpoint to analyze message performance, build deliverability reports, or track engagement trends across your campaigns and broadcasts.

• This endpoint retrieves all sent message records automatically. No additional parameters are required—select the List Messages template and proceed to endpoint testing to verify the response.
• Each record represents a single sent message and includes delivery status, channel (email, SMS, push, etc.), and engagement event flags such as opened, clicked, bounced, and unsubscribed.

Message engagement data is a valuable input for deliverability analysis and campaign performance reporting. Use Nexla to route this data to a data warehouse or BI tool for deeper analysis alongside other marketing metrics.

List Collections

Returns a list of data collections in your Customer.io workspace. Collections are lookup tables used in Liquid personalization—they allow you to reference structured data (such as product catalogs, pricing tables, or location lists) directly within Customer.io message content. Use this endpoint to audit or synchronize your workspace's collection library.

• This endpoint retrieves all collections automatically. No additional parameters are required—select the List Collections template and proceed to endpoint testing to verify the response.
• Each record represents a single collection and includes its name, ID, and schema information.

Collections are used in Liquid templating within Customer.io message content to insert dynamic, structured data into personalized messages. Retrieving collection metadata via Nexla is useful for maintaining documentation of your personalization data assets.

Endpoint Testing

Once the selected endpoint template has been configured, Nexla can retrieve a sample of the data that will be fetched according to the current settings. This allows users to verify that the source is configured correctly before saving.

• To test the current endpoint configuration, click the Test button to the right of the endpoint selection menu. Sample data will be fetched & displayed in the Endpoint Test Result panel on the right.

• If the sample data is not as expected, review the selected endpoint and associated settings, and make any necessary adjustments. Then, click the Test button again, and check the sample data to ensure that the correct information is displayed.

Configure Manually

Customer.io data sources can be manually configured to ingest data from any valid Customer.io App API endpoint. Manual configuration provides maximum flexibility for accessing endpoints not covered by pre-built templates or when you need custom API configurations such as filtered queries, paginated fetches, or chained API calls.

With manual configuration, you can also create more complex Customer.io sources, such as sources that use chained API calls to fetch data from multiple endpoints or sources that require additional query parameters beyond what the standard templates provide.

API Method

1. To manually configure this source, select the Advanced tab at the top of the configuration screen.

2. Select the API method that will be used for calls to the Customer.io App API from the Method pulldown menu. The Customer.io App API uses:

   • GET: For retrieving data (campaigns, customers, segments, activities, messages, etc.)
   • POST: For sending data or triggering actions (used when creating or triggering broadcasts)

API Endpoint URL

3. Enter the URL of the Customer.io App API endpoint from which this source will fetch data in the Set API URL field. All Customer.io App API requests use the following base URL pattern:

   • For US workspaces: https://api.customer.io/v1/{endpoint_path}
   • For EU workspaces: https://api-eu.customer.io/v1/{endpoint_path}

   For example, to list all campaigns for a US workspace, enter https://api.customer.io/v1/campaigns.

Ensure the API endpoint URL matches the region domain you selected when creating your Customer.io credential. Using the US domain for an EU workspace (or vice versa) will result in authentication or routing errors. For a complete list of available App API endpoints, see the Customer.io App API Reference.

Date/Time Macros (API URL)

Optional

Optionally, the API URL can be customized using macros—all macros added to the API URL will be converted into values when Nexla executes the API call. Macros are dynamic placeholders that allow you to create flexible API endpoints that can adapt to different time periods or data requirements.

Macros are particularly useful for Customer.io API endpoints that accept date range parameters, allowing you to incrementally fetch only new or updated records with each data flow run.

1. To add a macro, type { at the appropriate position in the API URL (within the Set API URL field), and select the desired macro from the dropdown list.

   • {now} – The current datetime
   • {now-1} – The datetime one time unit before the current datetime
   • {now+1} – The datetime one time unit after the current datetime
   • custom – Datetime macros can reference any number of time units before or after the current datetime—for example, enter (now-4) to indicate the datetime four time units before the current datetime

2. Select the format that will be applied to datetime macros from the Date Format for Date/Time Macro pulldown menu. This format will be applied to the base datetime value of the macro—i.e., the value of {now} in {now-1}.

3. Select the datetime unit that will be used to perform mathematical operations in the included macro(s) from the Time Unit for Operations pulldown menu—for example, for the macro {now-1}, when Day is selected, {now-1} will be converted to the datetime one day before the current datetime.

Lookup-Based Macros (API URL)

Optional

Column values from existing lookups can also be included as macros in the API URL. Lookup-based macros allow you to reference data from previously configured data sources or lookups, enabling dynamic API endpoints that can adapt based on existing data.

Lookup-based macros are useful when you need to build Customer.io API calls that reference specific campaign IDs, customer IDs, or segment IDs sourced from another Nexla dataset or lookup table.

1. To include a lookup column value macro, select the relevant lookup from the Add Lookups to Supported Macros pulldown menu.

2. Type { at the appropriate position in the API URL, and select the lookup column-based macro from the dropdown list. Lookup-based macros are automatically populated into the macro list when a lookup is selected in the Add Lookups to Supported Macros pulldown menu.

Path to Data

Optional

If only a subset of the data returned by a Customer.io API endpoint is needed, you can designate the part of the response that should be included in the Nexset(s) produced from this source by specifying the path to the relevant data within the response. Most Customer.io App API responses wrap the actual records in a named top-level key (for example, $.campaigns[*], $.customers[*], or $.segments[*]).

For example, when requesting the list of campaigns, the Customer.io API returns a JSON object with a top-level campaigns array. By entering $.campaigns[*] as the Path to Data, Nexla treats each element of that array as an individual record.

Path to Data is essential when working with Customer.io API responses, as the records of interest are consistently nested within named keys. Without specifying the correct path, Nexla may not be able to properly parse and organize the returned data into usable records.

• To specify which data should be treated as relevant in responses from this source, enter the path to the relevant data in the Set Path to Data in Response field.

  • For responses in JSON format enter the JSON path that points to the object or array that should be treated as relevant data. JSON paths use dot notation (e.g., $.campaigns[*] to access the campaigns array, $.segments[*] to access segments, $.messages[*] to access messages).
  Path to Data Example:

  If the API response is in JSON format and includes a top-level array named campaigns that contains the relevant data, the path to the response would be entered as $.campaigns[*].

Autogenerate Path Suggestions

Nexla can also autogenerate data path suggestions based on the response from the API endpoint. These suggested paths can be used as-is or modified to exactly suit your needs.

• To use this feature, click the Test button next to the Set API URL field to fetch a sample response from the API endpoint. Suggested data paths generated based on the content & format of the response will be displayed in the Suggestions box below the Set Path to Data in Response field.

• Click on a suggestion to automatically populate the Set Path to Data in Response field with the corresponding path. The populated path can be modified directly within the field if further customization is needed.

  

Metadata

If metadata is included in the response but is located outside of the defined path to relevant data, you can configure Nexla to include this data as common metadata in each record. This is useful when you want to preserve important contextual information that applies to all records but isn't part of the main data array.

For example, when fetching a list of Customer.io messages, the API response includes the messages array along with top-level metadata such as pagination cursors and totals. If you have specified the path to the relevant data as $.messages[*], you can still capture that surrounding metadata by specifying its path in this field.

Metadata paths are particularly useful for preserving API response context like pagination tokens, total record counts, or request timestamps that apply to all records in the response.

• To specify the location of metadata that should be included with each record, enter the path to the relevant metadata in the Path to Metadata in Response field.

  • For responses in JSON format, enter the JSON path to the object or array that contains the metadata.

Request Headers

Optional

• If Nexla should include any additional request headers in API calls to this source, enter the headers & corresponding values as comma-separated pairs in the Request Headers field (e.g., header1:value1,header2:value2). Additional headers may be required for specific Customer.io API endpoints that require content negotiation or custom parameters.

  You do not need to include the Authorization header here—it is automatically applied from your Customer.io credential configuration. The Customer.io App API also does not require a Content-Type header for GET requests.

Endpoint Testing

After configuring all settings for the selected endpoint, Nexla can retrieve a sample of the data that will be fetched according to the current configuration. This allows users to verify that the source is configured correctly before saving.

• To test the current endpoint configuration, click the Test button to the right of the endpoint selection menu. Sample data will be fetched & displayed in the Endpoint Test Result panel on the right.

• If the sample data is not as expected, review the selected endpoint and associated settings, and make any necessary adjustments. Then, click the Test button again, and check the sample data to ensure that the correct information is displayed.

Save & Activate the Source

1. Once all of the relevant steps in the above sections have been completed, click the Create button in the upper right corner of the screen to save and create the new Customer.io data source. Nexla will now begin ingesting data from the configured endpoint and will organize any data that it finds into one or more Nexsets.