Guide to CRM API Integrations

Editor's note: This is a series on API-based integrations. Check out Merge if you're looking to add 20+ CRM integrations with one CRM API.

CRM ("customer relationship management") systems are a critical part of all go-to-market operations, from marketing to sales to support. If you're building software aimed at any of those user segments, then CRMs are a critical integration for your platform. Whether you're just scoping out your first CRM integration, or already have a fully built our Salesforce or HubSpot integration, this guide will synthesize and summarize the often complex landscape of CRMs.

Read on to learn about:

  • Top CRM APIs - Which CRMs matter most
  • Key concepts - How CRMs work
  • Data schemas - How APIs organize customer data
  • Use cases - Common ways CRM data is used in product integrations
  • Getting started - Approaching CRM integrations to your product

Related: A guide to ERP API integration


Customer relationship management (CRM) is a massive business with over $70B in annual revenue. While several major players - Salesforce, Oracle, SAP, Microsoft, and Adobe - each have multi-billion dollar businesses, over the past years a long tail of function- and vertical-specific CRM platforms have emerged. 

To understand which CRMs you should integrate into, it’s key to recognize that the CRM market is comprised of several sub-markets. This includes:

Sales CRM

Primary Purpose: To manage customers through a sales process.

Biggest vendors: Salesforce Sales Cloud, Microsoft Dynamics, SAP, and Oracle.

Customer Service & Support CRM

Primary Purpose: Track and resolve customer support requests.

Biggest vendors: Salesforce Service Cloud, Genesys, and Zendesk.

Marketing CRM

Primary Purpose: Campaign management and marketing (email, text) communication. 

Biggest vendors: Adobe Marketo, Salesforce Marketing Cloud, and Hubspot

Digital Commerce CRM

Primary Purpose: Track customers through an online purchase process.

Biggest vendors: SAP Commerce Cloud, Salesforce Commerce Cloud, Shopify

Source: Gartner Market Share: Customer Experience and Relationship Management, Worldwide, 2020

Related: Guide to REST API integration

Key CRM Concepts

Leads and contacts

CRM systems vary in how they represent individuals. Nearly all CRMs have a concept of Contacts, which can typically be thought of as unique people or users. Contacts may also be associated with the company they work for as well as a sales Opportunity. Some CRMs (e.g. Salesforce) also have a concept of Leads. Leads differ from Contacts in that they aren’t associated with an Account or Opportunity and must be converted to a Contact as the sales process progresses. 

Custom objects and fields

Major CRM systems are highly customizable. They include the ability to define custom objects and custom fields on standard objects. Many integration use cases involve creating and updating these custom objects or fields.

CRM API Data Schemas

CRMs tend to hold a lot (we mean - A LOT) of data, much of it in custom objects and fields. Despite this, there is a common core of objects that most CRMs have to describe customer and account relationships. Here are the most common objects across CRMs that you’ll want to be familiar with as you integrate:

The core concept of a person or customer in a CRM system is Contacts, typically defined by a unique identifier such as email, phone, username, or ID number. Contacts contain standard information about the person including name, emails, addresses, titles, and phone numbers in addition to custom fields. Contacts are typically associated with Accounts (companies) and may be associated with Opportunities if they are in an active purchase process or are a customer.

Some CRM systems also have a concept of Leads, similar to Contacts in that they represent individuals but not associated with Accounts. Leads are usually earlier in the product evaluation process than Contacts and over time will be converted to Contacts. Leads have similar data as Contacts.  

Companies are represented in a CRM as Accounts and are associated to one or many Contacts that work at that company. Data on Accounts includes industry, website, number of employees, business addresses, and business phone numbers. 

Sales, subscription, or purchase processes are represented as Opportunities and are associated with an Account and/or Contact. Opportunities have fields with data on the value or amount of deal, the sales rep that owns the opportunity, and the status of the purchase.

As sales and support team members converse with Leads and Contacts, they will typically collect Notes about the current state of relationship. Notes can be associated with many record types, including Leads, Contacts, Accounts, and Opportunities. 

General Overview of Main CRM Endpoints

Related: Everything you need to know about CRM API integration

Top CRM API Use Cases

Marketing campaign management

A primary way CRMs add new leads or contacts is via marketing campaigns, including advertising, events, web forms, and social media. Campaign tools integrate with CRM systems to create new contacts, track multiple contact touch-points, record source and attribution, automatically create audience segments, personalize interactions, and report on campaign effectiveness.

Examples: Facebook, Google, Eventbrite, Hopin, Typeform, Unbounce

Marketo integrates with LinkedIn to capture lead data and track source attribution.

Lead and account prospecting and enrichment

Marketing and sales teams also actively prospect for new leads. Prospecting includes interactions such as emails, phone calls, texts, and gifts with integrations that create new contacts and map them to target accounts. CRM systems often integrate with enrichment tools that add or update contact, account, and behavioral intent data to facilitate prospecting.

Examples: LinkedIn, Outreach, Salesloft, Vidyard, Sendoso, Apollo, Clearbit, Demandbase

Sendoso integrates with Hubspot to send gifts to contacts and show gifting history.

Related: Comparing scraping with APIs

Routing and meeting scheduling

Once a lead converts and wants to chat with a sales or support person, leads and/or contacts need to be deduplicated, routed, assigned, and meetings need to be scheduled. CRM systems integrate show and record meeting activities, route leads and contacts to owners, create tasks, and show relevant contact information.

Examples: Chili Piper, Lean Data, Calendly

Hubspot integrates with Chili Piper to show meetings booked and completed.

Customer communication

CRMs commonly integrate with a variety of communication channels: chat, messaging, phone, video, and email to facilitate and keep track of conversations. Typical data flows include creating new contacts from conversations, populating contact info in the communication tool, sales or support rep routing for new conversations, and keeping a record of conversation history.

Examples: Intercom, WhatsApp, Aircall, Dialpad, Ringcentral, Zoom, Five9, Genesys, Twilio, Drift, Slack, Gong

Pipedrive integrates with Aircall to place a call, show call history, and listen to recordings.

Sales and support productivity

Customer conversations often trigger work that needs to get done, from onboarding to legal reviews to sales team follow up. CRMs integrate with productivity, enablement, and project tracking tools to kick off new workflows, update the status and comments on a project, highlight relevant sales playbooks, or show customer data related to a project.

Examples: Asana, ClickUp, Scratchpad, Highspot, Seismic

Zendesk integrates with ClickUp to create or link tasks back to customer tickets.

Ecommerce campaign management

Online shopping has a specialized set of use cases for CRM integrations. Ecommerce products integrate with CRMs to track product purchases and orders, automate customer communication across channels, and customize customer experience based on purchase behavior and cart abandonment.

Examples: Woo Commerce, Square, Shopify

Shopify integrates with Hubspot to automate and personalize conversations based on purchase behavior.

Contracts and quotes

Sales and purchase processes can have complex steps including contracts, quotes, and purchase orders. CRMs integrate with contract management, document management, and billing systems to trigger contact creation, progress opportunity stages, create quotes, and kick off document signing workflows.

Examples: Conga, Ironclad, HelloSign

Conga integrates with Salesforce for document-based workflows and contract management.

Billing, payments, and budgeting

Once it’s time to pay, a whole set of products integrate with CRM systems to coordinate billing, account receivables, and payment. Integration points include showing purchase items and products, displaying billing and payment activity, updating deal and account info, and creating payment links.

Examples: Xero, QBO, Netsuite, Freshbooks, Chargebee, Stripe

Hubspot integrates with Chargebee to reveal subscription information, invoices, and billing status.

Help desk and ticketing

Support CRM use cases involve ticketing, help desk, and field service management tools. CRM integrations with these tools include creating and updating tickets, creating new contacts from support cases, kicking off customer communication, routing tickets to agents/reps, and populating customer data in the ticketing system.

Examples: Jira, Help Scout, PagerDuty 

Help Scout integrates into Salesforce to show active conversations on a contact, account, lead, or opportunity record.

Customer health and churn management

Support teams also manage longer term customer health with onboarding, survey, and churn management tools. Integrations to CRM systems include calculating customer health scores, kicking off onboarding workflows, and showing current contact and opportunity details.

Examples: ChurnZero, Vitally, SurveyMonkey, Gainsight

Zendesk integrates with ChurnZero to show health scores and usage details alongside tickets.

Getting Started with CRM APIs

In addition to understanding CRM API structures, you’ll also want to keep in mind a few additional topics as you start building:

  • API format - REST, SOAP, etc.
  • Authentication
  • Pagination
  • Rate Limits 
  • Test Accounts

With so many CRM systems out there, chances are you’ll want to integrate with more than one. Merge unified multiple CRM APIs into one, making it easy to integrate your app with every CRM that your customers use.  Our Unified CRM API is REST-based, with common authentication, pagination, and rate limiting. It also includes automated logging and issue detection to make integration maintenance painless.