Customer.io
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Customer.io Integration

Sync ad leads to Customer.io as identified customers -- triggering behavior-based messaging campaigns automatically with every new form submission.

Available Integrations

Connect Customer.io with 4 lead sources

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Customer.io
Facebook to Customer.io
Sync leads from Facebook & Instagram Lead Ads to Customer.io in real time.
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Customer.io
Google Ads to Customer.io
Sync leads from Google Ads Lead Form Extensions to Customer.io in real time.
Read guide
Customer.io
LinkedIn to Customer.io
Sync leads from LinkedIn Lead Gen Forms to Customer.io in real time.
Setup guide
Customer.io
TikTok to Customer.io
Sync leads from TikTok Lead Generation to Customer.io in real time.
Setup guide
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How It Works

1
Connect Your Ad Account
Link your Facebook, Google, LinkedIn, or TikTok ad account to LeadSync in one click.
2
Choose Customer.io
Select Customer.io as your destination and authenticate your account.
3
Map Your Fields
Match your lead form fields to Customer.io and start syncing leads instantly.

How LeadSync Identifies Each Lead in Customer.io

Customer.io is built around identified people -- every record needs a stable identifier the rest of your messaging stack can key off. LeadSync connects to the Customer.io Track API at track.customer.io/api/v1 using HTTP Basic auth (your Site ID as username, API key as password) and PUTs each Facebook, Google, LinkedIn, or TikTok lead as an identified person record with the lead form data attached as attributes.

Setup is two values from your Customer.io Workspace settings: the Site ID and the API Key from the Tracking API Keys section under Account Settings. Paste both into LeadSync and the integration is wired -- there is no OAuth flow, no per-list selection, just identify-and-trigger.

Custom Attributes Power Your Segments and Campaigns

Every field on your ad form lands in Customer.io as a person attribute. Email, first name, last name, and phone are passed through directly; lead-form custom questions become custom attributes that you can immediately use in Customer.io Segments, Campaign entry conditions, and Liquid template tags inside email or push copy.

LeadSync also exposes a per-connection Custom attribute field that gets stamped on every lead from that connection. Use it to tag the lead source -- "fb_paid_social", "linkedin_b2b", "tiktok_lead_gen" -- so a single Customer.io Segment can isolate one channel for attribution reporting or for excluding cold leads from broadcast sends.

Event-Triggered Campaigns Fire on Identification

Once a lead is identified, any People-trigger Campaign with a matching entry condition fires automatically -- the same way it would for someone who signed up via your website. This is the cleanest pattern for paid-social welcome flows: build the Campaign once in Customer.io, set the entry condition to match the custom attribute LeadSync stamps on incoming leads, and every Facebook lead enters the journey within seconds of submitting the form.

Because Customer.io supports cross-channel messaging from a single profile -- email, SMS, push, in-app, transactional -- the same identified record powers your full follow-up sequence. No separate sync to a second tool, no duplicate-attribute drift between channels.

Frequently Asked Questions

In Customer.io, go to Account Settings > API Credentials > Tracking API Keys and copy your Site ID and API Key. Paste both into LeadSync when adding Customer.io as a destination. There is no OAuth flow -- the two values are all the integration needs.
LeadSync uses the Customer.io Track API endpoint at track.customer.io/api/v1/customers, which is the standard ingestion endpoint for identifying people. It uses HTTP Basic auth with the Site ID and API Key from your Workspace.
LeadSync sets the customer ID to a stable string derived from the lead, so repeat submissions from the same person update the same Customer.io record rather than creating a duplicate. The email address is also stored as the email attribute so you can use it in messaging.
Yes. Any Customer.io Campaign with a People entry condition that matches the incoming attributes fires automatically. The standard pattern is to set up a Campaign with an entry condition like attribute equals lead source name, and every lead LeadSync identifies enters the Campaign within seconds.
Yes. The Custom Attribute field in the LeadSync connection settings stamps the value on every lead from that connection. Set it to fb_paid_social on your Facebook connection, linkedin_b2b on your LinkedIn connection, and so on -- you can then segment or filter Campaigns by that attribute.
Each lead form question becomes a custom attribute on the person record. Custom attributes are immediately usable in Segments, Campaign entry conditions, and Liquid template tags in your email, SMS, or push copy. You do not need to predefine the attribute schema in Customer.io.
No. The Track API upserts on the customer identifier, so a repeat submission updates the existing person record. Their attribute history accumulates and any segments they qualify for stay accurate.
Yes. LeadSync supports Customer.io as a destination for lead forms from Facebook, Instagram, Google Ads lead form extensions, LinkedIn Lead Gen Forms, and TikTok Lead Generation. Each source is its own connection so you can stamp different source attributes per channel.
Yes. The Track API is available on every Customer.io plan including the free tier and the Essentials plan, so any Workspace can ingest leads via LeadSync. The Site ID and API Key are issued the moment your Workspace is created.
Yes. Each Workspace has its own Site ID and API Key pair. Create one LeadSync connection per Workspace and paste in the matching credentials -- leads route to whichever Workspace owns the keys you used.

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