Real-time
Two-way sync
Changes in Customer.io or Firebase instantly reflect in both systems. No stale data, no manual imports.
Business productivity ⇄ Database
Customer.io to Firebase integration — real-time, two-way sync
Keep Customer.io and Firebase in sync without custom scripts. Cut weeks of integration work, eliminate silent data drift, and give your team a single, reliable source of truth.
- SOC 2 and 6 other compliance frameworks
- POC with real engineers in minutes
Adopted by fast-scaling companies moving mission-critical data in real time
Case study
Migrated from Mulesoft
Case study
Migrated from Celigo
Migrated from Heroku Connect
Migrated from Matillion
Case study
Migrated from Fivetran
Case study
Migrated from Celigo
Why teams connect Customer.io and Firebase
Mirror Customer.io's data into Firebase so your own code can read and write it like any other table, with changes flowing both ways in seconds.
Engineers integrate with tools like Customer.io through APIs, which means auth, pagination, rate limits, webhooks, and retry logic, all maintained forever and all different for every tool. Meanwhile the data would be trivial to use if it simply lived in Firebase.
Stacksync mirrors Events, Segments, Campaigns, Broadcasts from Customer.io into Subcollections, Realtime Database Nodes, Authentication Users, Cloud Storage Objects in Firebase and keeps both sides in sync in real time. Your services query the database directly, and inserts or updates your code makes flow back into Customer.io, so the tool and the database never disagree.
Common use cases
- Land delivery and engagement events (sent, opened, clicked, bounced) from reporting webhooks into a warehouse for attribution analysis.
- Keep unsubscribe and subscription-preference state consistent between Customer.io and the CRM to avoid compliance gaps.
- Combine Firebase Authentication users with billing and CRM records into one customer table.
- Replace one-off Cloud Functions export code with managed, continuous sync.
Read Customer.io with a query
Records from Customer.io are ordinary rows in Firebase; join them, index them, and use them in application logic without touching the vendor API.
Automate Customer.io from your codebase
Write to the synced tables in Firebase and Stacksync propagates the change into Customer.io, replacing custom integration code.
React to changes as they happen
Updates in Customer.io arrive as row changes in Firebase, so triggers, jobs, and services can respond in near real time.
What you can sync between Customer.io and Firebase
Representative objects on each side — any object or custom field can map to any target. Schemas are auto-detected; types are converted between the two systems.
| Customer.io objects | Firebase objects | |
|---|---|---|
| Campaigns Automated workflows whose membership and metrics can be read via the App API. | Firestore Documents Schemaless JSON-like records, the primary unit synced to and from external systems. | |
| Broadcasts One-off sends to segments or audiences, triggerable via API. | Subcollections Nested collections under documents, typically flattened into related tables during sync. | |
| Deliveries / Messages Per-recipient message records whose lifecycle events flow out through reporting webhooks. | Realtime Database Nodes JSON tree paths in the older Realtime Database, synced by path. | |
| Newsletters Recurring email sends with performance metrics available for reporting syncs. | Authentication Users User accounts read into CRMs and warehouses for customer records. | |
| People Profiles with attributes, matched on identifiers like id or email; the main write target of data syncs. | Cloud Storage Objects Files referenced from documents; usually synced as metadata plus URLs. | |
| Objects Non-person entities such as accounts or companies, related to people for account-level messaging. | Cloud Functions Triggers Server-side hooks that fire on document changes and can push updates outward. |
What ships with Customer.io ⇄ Firebase
Connect Customer.io and Firebase for flexible, real-time data sync.
Real-time sync, workflow automation, event queues, EDI, and monitoring, for every Customer.io–Firebase connection.
No-code + pro-code
Workflow automation
Trigger automated workflows whenever Customer.io or Firebase data changes, update records, fire webhooks, or kick off sequences without brittle API scripts.
At scale
Event queues
Handle millions of events per minute without losing a single Customer.io or Firebase record.
Observability
Monitoring
Track your Customer.io ⇄ Firebase sync health, view errors, and replay failed events in one click.
Trading partners
EDI
Transform legacy EDI complexity into simple database interactions between Customer.io and Firebase.
How the Customer.io and Firebase connectors work
Customer.io
- Integration surface
- REST APIs split by purpose: Track API for data ingestion, App API for campaigns, people lookups, and messages
- Authentication
- Basic auth with site ID and API key for the Track API; bearer token for the App API
- Change detection
- Reporting webhooks push message and delivery events; person attribute changes are not streamed and require source-side detection
- Capabilities
- read · write · webhooks
- Rate limits
- Subject to per-API rate limits documented by Customer.io
Firebase
- Integration surface
- REST and gRPC APIs, typically accessed through the Firebase Admin SDK
- Authentication
- Google service account credentials (IAM) for server-side access; Firebase Auth tokens for client contexts
- Change detection
- Real-time snapshot listeners on Firestore queries and Cloud Functions triggers on document changes
- Capabilities
- read · write
- Rate limits
- Subject to Firestore's documented operation quotas and per-document write throughput limits
How it works
How to connect Customer.io to Firebase — three steps, no code
Configure and sync within minutes, no code. Whether you sync 50k or 100M+ records, Stacksync handles the queues, infra, and plumbing. Integrations are non-invasive and need zero setup on your systems.
- 01
Connect your apps
Authenticate Customer.io and Firebase with each platform's native method — OAuth, API keys, or service accounts — plus secure options like SSH tunneling, IP whitelisting, and VPC peering.
Customer.io
connected
Firebase
connected
OAuth 2.0SSH tunnelSSL certificateVPC peering - 02
Choose tables
Pick the Customer.io and Firebase objects to sync — Stacksync auto-detects both schemas, including custom fields where the platform exposes them. Sync to existing tables, or let Stacksync create new ones with ideal data types.
objects · Customer.io ⇄ FirebaseCustomers 12,480Sales Orders 8,213Invoices 5,902Items 1,344 - 03
Map fields
Fields map automatically even when names and types differ. Stacksync handles transformation and type casting for you, zero configuration required.
Customer.io FirebaseCompany company_name textEmail email textAmount amount numericCreated created_at timestamp
FAQ
Customer.io and Firebase integration FAQ
-
Yes. Stacksync provides a managed, real-time two-way integration between Customer.io and Firebase: authenticate both systems, choose the objects to sync (such as Customer.io's Campaigns and Broadcasts), map fields visually, and changes propagate both ways in milliseconds — no code required.
-
On the Customer.io side: Events, Segments, Campaigns, Broadcasts, plus custom fields where Customer.io exposes them. On the Firebase side: Subcollections, Realtime Database Nodes, Authentication Users, Cloud Storage Objects. Stacksync auto-detects both schemas and converts types between the two systems.
-
Yes. Each object mapping can be bidirectional or restricted to a single direction (both systems accept writes). Read-only mirrors, one-way pushes, and full two-way sync can be mixed in the same integration.
-
Common patterns for Customer.io and Firebase: Read Customer.io with a query; Automate Customer.io from your codebase; React to changes as they happen. Records from Customer.io are ordinary rows in Firebase; join them, index them, and use them in application logic without touching the vendor API.
-
Customer.io: REST APIs split by purpose: Track API for data ingestion, App API for campaigns, people lookups, and messages. Authentication: Basic auth with site ID and API key for the Track API; bearer token for the App API. Firebase: REST and gRPC APIs, typically accessed through the Firebase Admin SDK. Authentication: Google service account credentials (IAM) for server-side access; Firebase Auth tokens for client contexts. Stacksync manages authentication, retries, and rate limits on both sides.
-
Customer.io: Beyond people, Customer.io supports non-person objects (for example accounts) with typed relationships to people, enabling account-based messaging logic. Firebase: Firestore documents are schemaless and support nested maps and arrays, so syncs define field mappings per document path rather than from a fixed schema. Stacksync's field mapping accounts for these differences between Customer.io and Firebase without custom code.
SECURITY
Security teams love Stacksync
As a data company, we understand the importance of keeping your data secure. Stacksync is built with security best practices to keep your data safe at every layer, and is DPF-certified for US, EU, UK and CH data transfers.
SOC 2 type II
ISO 27001
HIPAA BAA
GDPR
CCPA
CSA STAR
DPF US-EU-UK-CH
→ SECURITY WITH BENEFITS
SSO & SCIM
Let your users access Stacksync from your centralized user management systems. Works with Okta, Azure, Google SSO and more.
Alerts
Immediately get alerted about record syncing issues over email, Slack, PagerDuty and WhatsApp. Resolve issues from a centralized dashboard with retry and revert options.
Secure connection options
Securely connects to your systems with:
Related integrations
Every pair below is a real-time, two-way sync. Search all 386 integrations available for Customer.io and Firebase.
Popular · 8 of 386
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Customer.io ⇄ Supabase -
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Firebase ⇄ Amazon Seller Central -
Firebase ⇄ SendGrid -
Firebase ⇄ Twilio -
Firebase ⇄ GitHub
No integrations match .
