--- title: "Two-way sync: real-time synchronization across your stack" description: "Connect CRM, ERP, and database records with two-way sync. Plan field mappings, write permissions, API limits, and recovery with Stacksync." canonical: https://www.stacksync.com/two-way-sync last_modified: 2026-09-15 --- Enterprise two-way sync # Two-way sync across your entire stack, with control over what changes where. Connect your CRM, ERP, and databases. Map the records your teams share, choose the permitted sync directions, and keep operational data aligned. [Book a demo](https://www.stacksync.com/book-a-demo) [Start now](https://app.stacksync.com/) We'll build your first integration on the call. SOC 2 · ISO 27001 · HIPAA. ## Built for teams where self-serve, reliability and scale matter - Gladia Case study - IDEXX - MedPro Migrated from MuleSoft - Eko Case study - Ubicloud - Vimeo - Codility Migrated from Celigo - ACERTUS Migrated from Heroku Connect - Syringa Migrated from Matillion - Truora - Streaam Case study - SEAL SQ - Rinsed Migrated from Fivetran - IA Capital Group Case study - Meter - Golden Pear Funding Migrated from Celigo STACKSYNC FEATURES ## Everything real-time two-way sync needs. Schema drift, API rate limits, failed records and sync cadence are the conditions to plan for in production. Review your mappings, allocate API capacity, and give your team a clear process for resolving sync issues. SCHEMA ### Review mappings as your schemas change. Stacksync proposes field mappings that you can adjust. Field names can differ, but their types must be compatible. Recheck your configuration when a connected system changes its schema. [Read the mapping setup guide](https://docs.stacksync.com/start-here/quick-start) 1. 01 Choose the tables and fields needed for your use case 2. 02 Review suggested mappings and compatible data types 3. 03 Check connector-specific requirements before renaming fields or tables A mapping review Record identity Which identifier connects the same record across systems? Field meaning Do both fields represent the same value with compatible types? Write access Which fields can each connection actually update? Review these decisions with representative records before enabling a broader sync. RATE LIMITS ### Set an API budget for each connected app. Configure API limits in Stacksync to share capacity with your other integrations. Tighter budgets protect capacity but can delay updates until more API calls become available. [Read the API rate-limit guide](https://docs.stacksync.com/two-way-sync/features/manage-api-rate-limits) 1. 01 Set limits for the time windows that matter to your systems 2. 02 Leave room for other applications using the same API quota 3. 03 Monitor freshness when a limit constrains throughput Capacity planning Available API calls Account for the provider limit and other applications sharing it. Configured budget Allocate capacity to the sync for the appropriate time window. Observed freshness Check the effect on delivery during busy periods. Direction and throughput are separate: a two-way sync still depends on each endpoint’s capacity. ISSUE MANAGEMENT ### Inspect failed records and choose how to recover. The Issues dashboard shows records that could not sync and the reason. Correct validation or configuration problems, then retry using the source’s current values or revert the affected fields. [Read the issue-resolution guide](https://docs.stacksync.com/two-way-sync/features/issues-dashboard) 1. 01 Inspect issue details and recommended resolution steps 2. 02 Retry reads the latest source record before attempting the write 3. 03 Apply resolution actions to individual records or a selected group Record recovery Inspect Find the failed record and understand the destination error. Correct Fix the value, validation rule, permissions, or configuration. Retry and verify Read the current source state, retry the write, and check the result. A retry uses current record values. It is not a replay of an immutable historical event. SYNC FREQUENCY ### Plan for the timing of each connector. Define how fresh the destination data must be. Check change detection, API capacity, and destination writes for each connection, then measure the result under the workload you expect. [Find your connector requirements](https://www.stacksync.com/connectors) 1. 01 Distinguish the initial data load from ongoing updates 2. 02 Verify each connector’s prerequisites and supported change-detection method 3. 03 Test both directions when both systems will accept changes Measure each direction Source change Create a known test change in the source system. Destination result Check when the expected value appears and whether it is correct. Reverse direction Repeat for the writable data flowing back to the first system. Test during normal operation and expected peak load; document the freshness your workflow requires. CONNECTORS ## 1,000+ connectors. And AI builds for the rest. We support every major SaaS and database out of the box. If yours isn't listed, paste an API URL and our agent will spec and build a connector, typically in under a minute. [Salesforce](https://www.stacksync.com/connectors/salesforce) [HubSpot](https://www.stacksync.com/connectors/hubspot) [NetSuite](https://www.stacksync.com/connectors/netsuite) [Zendesk](https://www.stacksync.com/connectors/zendesk) [Microsoft Dynamics 365 Sales](https://www.stacksync.com/connectors/microsoft-dynamics-365-sales) [Dynamics 365 F&O](https://www.stacksync.com/connectors/dynamics-365-finance-operations) [Attio](https://www.stacksync.com/connectors/attio) [Pipedrive](https://www.stacksync.com/connectors/pipedrive) [Zoho CRM](https://www.stacksync.com/connectors/zoho-crm) [Campfire](https://www.stacksync.com/connectors/campfire) [Rillet](https://www.stacksync.com/connectors/rillet) [Front](https://www.stacksync.com/connectors/front) [Shopify](https://www.stacksync.com/connectors/shopify) [Amazon Seller Central](https://www.stacksync.com/connectors/amazon-seller-central) [SendGrid](https://www.stacksync.com/connectors/sendgrid) [PostgreSQL](https://www.stacksync.com/connectors/postgresql) [Amazon RDS](https://www.stacksync.com/connectors/amazon-rds) [Snowflake](https://www.stacksync.com/connectors/snowflake) [Supabase](https://www.stacksync.com/connectors/supabase) [MySQL](https://www.stacksync.com/connectors/mysql) [SuiteAnalytics](https://www.stacksync.com/connectors/suite-analytics) [MariaDB](https://www.stacksync.com/connectors/mariadb) [SQL Server](https://www.stacksync.com/connectors/sql-server) [BigQuery](https://www.stacksync.com/connectors/bigquery) [MotherDuck](https://www.stacksync.com/connectors/motherduck) [Postgres Heroku](https://www.stacksync.com/connectors/postgres-heroku) [Airtable](https://www.stacksync.com/connectors/airtable) [AWS Aurora MySQL](https://www.stacksync.com/connectors/aws-aurora-mysql) [AWS Aurora PostgreSQL](https://www.stacksync.com/connectors/aws-aurora-postgresql) [Twilio](https://www.stacksync.com/connectors/twilio) [Browse the full catalog →](https://www.stacksync.com/connectors) Connector agent Don't see your app? Paste a URL. | | | | | --- | --- | --- | | | Fetched OpenAPI spec 47 endpoints discovered | OK | | | Inferred auth, OAuth 2.0 Authorization code flow | OK | | | Generated 12 trigger templates customer.created · order.paid · … | OK | | | Validating against sandbox running 24 test calls | … | [Generate connector](https://www.stacksync.com/connectors) What is two-way sync? Two-way sync, also called bidirectional synchronization, keeps selected records aligned between two systems by carrying permitted changes in either direction. Stacksync connects your apps, maps their tables and fields, and lets you choose which data to sync. Both sides must support the intended writes; timing depends on the connectors and configuration. ## Choose which system can change the data A sync connects records that represent the same business information. The direction determines where an edit may originate; the change-detection method and delivery conditions determine when it arrives. **Write permissions for two-way sync and source-to-destination transfers** | Decision | Source-to-destination transfer | Two-way sync | | --- | --- | --- | | Where edits originate | The designated source | Either system, for the writable fields selected | | Typical use | A reporting copy or a read-only operational view | Two teams updating shared customer or operational records | | What to decide first | Source ownership and destination permissions | Record matching, field ownership, and conflicting-edit behavior | | What still needs testing | Mapping, freshness, and failed writes | Those checks in each permitted direction | Stacksync lets you select table direction and fields; read-only fields retain their restrictions. [Read the direction and field limitations.](https://docs.stacksync.com/two-way-sync/features/two-way-sync) ## How to connect two systems with Stacksync A production integration needs a mapping and an operating plan. Start with one useful flow and confirm the expected behavior before adding more records or systems. 1. ### Define the shared records Choose the business outcome and the objects that support it: for example, customer details in a CRM and an operational database. Specify which team owns each field. 2. ### Check both connections Review the connector guides for authentication, permissions, supported objects, and write restrictions. Separate the initial data load from ongoing change synchronization. 3. ### Map tables and fields Connect both apps, select the tables, choose a direction, and review the suggested field mappings. Check compatible types and how existing records will be reconciled. 4. ### Test changes and failures Use a small representative dataset. Confirm permitted edits in each direction, read-only behavior, matching, validation failures, and recovery before broadening access. 5. ### Operate with an owner Enable the sync, inspect the Issues dashboard, and measure freshness. Assign someone to review failures and configuration changes as the connected systems evolve. Follow the [Stacksync quick start](https://docs.stacksync.com/start-here/quick-start) for the setup screens, then use the [Issues dashboard guide](https://docs.stacksync.com/two-way-sync/features/issues-dashboard) when validating recovery. [Plan your first integration with our engineers →](https://www.stacksync.com/book-a-demo) ## Plan and operate a two-way sync Use these guides to define record ownership, map fields, and prepare an integration for production. - [guide Two-Way Sync Field Mapping Workbook](https://www.stacksync.com/blog/two-way-sync-field-mapping-workbook) - [deep dive Two-Way Sync Error Handling: Retries and Replay](https://www.stacksync.com/blog/two-way-sync-error-handling-retries-replay) - [checklist Two-Way Sync Production-Readiness Checklist](https://www.stacksync.com/blog/two-way-sync-production-readiness-checklist) - [guide Integration Evaluation Worksheet: Compare Sync Options](https://www.stacksync.com/blog/integration-evaluation-worksheet) - [comparison ETL vs Reverse ETL vs Two-Way Sync: Choose the Data Flow](https://www.stacksync.com/blog/etl-vs-reverse-etl-guide-modern-data-integration) - [guide Salesforce API Limits: Check Usage and Plan Reliable Sync](https://www.stacksync.com/blog/bypass-salesforce-api-limits-real-time-bi-directional-sync) FAQ ## Two-way sync questions ### How does two-way sync handle updates from both systems? Two-way sync allows changes to selected writable data in either connected system to reach the other. A source-to-destination transfer copies selected changes only from the designated source. With Stacksync, configure write direction for the data you share; fields owned by one system can retain their write restrictions. [Sync direction documentation](https://docs.stacksync.com/two-way-sync/features/two-way-sync) ### Does two-way sync mean every field is writable? No. Managed IDs, computed values, and other read-only fields retain their write restrictions within two-way sync. Database views can supply data to the other app, but they cannot accept writes back. Review permissions and field restrictions for each connector. [Read-only fields and view limitations](https://docs.stacksync.com/two-way-sync/features/two-way-sync) ### Will enabling two-way sync merge existing duplicates? No. Stacksync does not automatically merge duplicate records when two-way sync is first activated. Decide how existing records will be reconciled before enabling the sync; the documentation recommends starting with one empty side where practical. [Initial synchronization limitations](https://docs.stacksync.com/two-way-sync/features/two-way-sync) ### Do field names and types have to match? Field names can differ. Stacksync proposes field mappings that you can review and change. Field types must be semantically compatible, so test dates, identifiers, currencies, and required values with representative records before expanding the sync. [Table and field mapping setup](https://docs.stacksync.com/start-here/quick-start) ### How quickly will a change reach the other system? Direction and speed are separate decisions. Delivery depends on the connector’s change-detection method, API capacity, destination behavior, and the configured limits. A constrained API budget can delay updates. Measure both directions with your actual objects and workload instead of assuming a universal latency. [API budgets and sync delays](https://docs.stacksync.com/two-way-sync/features/manage-api-rate-limits) ### What happens when a record fails to sync? The Issues dashboard identifies affected records and provides error details. After correcting the cause, retry reads the current source values and attempts the write again. Revert uses the other system’s values to restore the affected fields. Select the action that matches the state you want to preserve. [Issue resolution and retry behavior](https://docs.stacksync.com/two-way-sync/features/issues-dashboard) CUSTOMER STORIES ## Global enterprises and high-growth teams run on Stacksync. E-Commerce · DTC · Provo, UT ### Black Friday at scale, without losing a single order. Just Ingredients runs a high-volume DTC business on a stack that has to absorb traffic spikes without dropping an order. Stacksync moves orders, customers and inventory between Shopify, NetSuite and the warehouse in real time, even on the heaviest days of the year. | | | | | --- | --- | --- | | Black Friday | survived without incident | Real-time order + inventory sync | | 0 | orders lost | Lossless triggers, replayable end-to-end | [Scale your e-commerce for Black Friday](https://www.stacksync.com/book-a-demo) Renewable Energy · Enterprise · Summit, NJ ### Production data flows across HubSpot, NetSuite and Postgres. Nautilus Solar manages community-solar portfolios with production data flowing across HubSpot, NetSuite and Postgres. Stacksync supports these core integrations following the company's move from Boomi, with additional workflow and EDI requirements managed on the same platform. | | | | | --- | --- | --- | | 3 | core systems connected | HubSpot · NetSuite · Postgres | | Production | integration environment | Expanded beyond legacy iPaaS | [Connect customer, finance and operational data](https://www.stacksync.com/book-a-demo) Interactive Commerce · Media Tech · New York, NY ### Engineers back on the core product. Eko's engineering team was spending sprints on brittle integration plumbing. Stacksync took over the syncs and workflows between their CRM, data warehouse and product app stack, freeing significant engineering capacity for product innovation. | | | | | --- | --- | --- | | 100% | integration ops handed off | CRM, warehouse and product app stack | | Weeks | reclaimed per quarter | Redirected to the product roadmap | [Free your engineers from integration work](https://www.stacksync.com/book-a-demo) Automotive Logistics · Enterprise · St. Louis, MO ### From Heroku Connect to a real-time competitive edge. ACERTUS replaced Heroku Connect with Stacksync's real-time, two-way sync between Salesforce and Postgres. Data integration stopped consuming their best engineers and became infrastructure they could build on, reliably, at scale. | | | | | --- | --- | --- | | Heroku | Connect → Stacksync | Migrated without downtime or data loss | | 24/7 | real-time two-way sync | Salesforce ⇄ Postgres, conflict-resolved | [Replace Heroku Connect with real-time two-way sync](https://www.stacksync.com/book-a-demo) Coffee Hardware · DTC · San Francisco, CA ### A connected stack from the showroom to the warehouse. Fellow ties together its e-commerce, retail and back-office systems with Stacksync. Inventory, orders and customer data move in real time between Shopify, NetSuite and their support tools, so every team works from the same picture. | | | | | --- | --- | --- | | One | source of truth across systems | Shopify ⇄ NetSuite ⇄ support stack | | Days | to roll out new flows | No-code config, version-controlled | [Unify your retail and back-office stack](https://www.stacksync.com/book-a-demo) SECURITY ## Security teams trust 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. [Learn more about security](https://www.stacksync.com/security) | | | | --- | --- | | | SOC 2 Type II | | | ISO 27001 | | | HIPAA BAA | | | GDPR | | | CCPA | | | 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: [OAuth 2](https://www.stacksync.com/security) [SSH Tunnelling](https://docs.stacksync.com/two-way-sync/connectors/setup-options/ssh-tunneling) [SSL certificates](https://docs.stacksync.com/two-way-sync/connectors/postgres/authorize-postgres/amazon-rds/ensuring-secure-rds-connections-with-ssl-certificate) [IP Whitelisting](https://docs.stacksync.com/two-way-sync/connectors/setup-options/ip-whitelisting) [VPN gateway](https://docs.stacksync.com/two-way-sync/legal/service-consumption-tables#:~:text=%E2%9C%93-,VPN%20gateway,-%2D) [VPC peering](https://www.stacksync.com/security) and more LEGACY IPAAS MIGRATION FUND ## Still under contract? We cover the buyout. Stacksync buys back your current contract with Boomi, Celigo, Workato, or MuleSoft. No migration cost, no overlap billing. [Check your eligibility for the migration fund](https://www.stacksync.com/book-a-demo) | | | | --- | --- | | | Migrate from Boomi | | Celigo | Migrate from Celigo | | | Migrate from Workato | | | Migrate from MuleSoft | | | Migrate from Heroku Connect | ## Keep your business systems in sync. See your workflow in action. [Book a demo](https://www.stacksync.com/book-a-demo) [Get started](https://app.stacksync.com/) Find your operating context ## Integration and automation for your industry ### [Construction services and installation](https://www.stacksync.com/industry/construction) Connect customer, project, material and billing records for companies that sell, supply, install and maintain physical systems. - [Commercial HVAC, plumbing and electrical contractors](https://www.stacksync.com/industry/construction/commercial-mep-contractors) - [Commercial flooring and interior installation](https://www.stacksync.com/industry/construction/commercial-flooring-interiors) - [Fire, life-safety and security integrators](https://www.stacksync.com/industry/construction/fire-life-safety-security-integrators) - [Solar installation and O&M services](https://www.stacksync.com/industry/construction/solar-installation-service) - [Fencing fabrication and installation](https://www.stacksync.com/industry/construction/fencing-fabrication-installation) - [Modular and prefab building supply and installation](https://www.stacksync.com/industry/construction/modular-prefab-building-installation) ### [Consumer packaged goods](https://www.stacksync.com/industry/cpg) Two-way sync, workflow automation, Genies, and EDI for CPG companies combining manufacturing, distribution, wholesale, and ecommerce. - [Packaged food and snacks](https://www.stacksync.com/industry/cpg/packaged-food-snacks) - [Nutrition and supplements](https://www.stacksync.com/industry/cpg/nutrition-supplements) - [Beverages](https://www.stacksync.com/industry/cpg/beverages) - [Personal care](https://www.stacksync.com/industry/cpg/personal-care) - [Household consumables](https://www.stacksync.com/industry/cpg/household-consumables) - [Pet food and treats](https://www.stacksync.com/industry/cpg/pet-food-treats) ### [Manufacturing](https://www.stacksync.com/industry/manufacturing) Two-way sync, workflow automation, Genies and EDI for manufacturers whose customer commitments depend on current production, purchasing and service records. - [Metal fabrication and machining](https://www.stacksync.com/industry/manufacturing/metal-fabrication-machining) - [Plastics and molding](https://www.stacksync.com/industry/manufacturing/plastics-molding) - [Industrial equipment and machinery](https://www.stacksync.com/industry/manufacturing/industrial-equipment-machinery) - [Building products manufacturing](https://www.stacksync.com/industry/manufacturing/building-products) - [Automotive components](https://www.stacksync.com/industry/manufacturing/automotive-components) - [Electrical and electronic components](https://www.stacksync.com/industry/manufacturing/electrical-electronic-components)