On this page
Why software needs to talk to other software
Most businesses use several tools: a website, a CRM, a calendar, a payment provider, an email service. Unless these exchange information, someone has to copy it by hand. Integrations are the mechanisms that move data and trigger actions between tools automatically.
APIs: asking another system for something
An API (application programming interface) is a defined way for one program to ask another to do something or return something. Think of a restaurant: the menu lists what you may request, and the waiter carries the request to the kitchen and brings back the result. You do not need to know how the kitchen works.
Typical API requests: create a contact, get the appointments for tomorrow, mark an invoice as paid. Each request goes to a specific web address, includes the required details and usually proves who is asking through a key or token. Well-run APIs are documented so that developers know what is available.
Webhooks: being told when something happens
An API normally requires you to ask. A webhook reverses the direction: when an event occurs in system A, it automatically sends a small message to a web address you provide in system B. For example, when a payment succeeds, the payment tool notifies your CRM, which updates the customer record in seconds.
Polling versus webhooks
Without webhooks, a system must poll, meaning ask every few minutes, "anything new?" Polling works but is slower and wasteful. Webhooks are immediate and efficient, though the receiving system must be reachable and able to handle retries, because messages can occasionally be duplicated or arrive out of order.
Native integrations, connectors and custom work
There are three common ways to connect tools:
- Native integrations are built and maintained by the software vendor, usually set up with a few clicks.
- No-code connectors are third-party automation services with a library of prebuilt triggers and actions. They suit many workflows without programming.
- Custom integrations are coded against APIs and webhooks for needs the other options cannot meet.
Native integrations are usually simplest but may be limited in what they expose. Custom work is the most flexible and the most costly to maintain.
What can go wrong
- Duplicate records when the same person is created twice by different systems.
- Field mismatches, for example a "phone" field that one tool splits into country code and number and another does not.
- Authentication expiry, where a connection silently stops working after a token expires.
- Rate limits, which cap how many requests a system accepts per minute.
- Silent failures, where errors occur but nobody is alerted.
- Changes by vendors, which can break integrations when APIs are updated.
Good habits
- Decide which system is the source of truth for each type of data.
- Map fields deliberately before connecting anything.
- Test with sample records and check both directions.
- Set up alerts for failed automations.
- Document each integration: what it does, who owns it and where the credentials are stored.
- Limit access, and use the least privilege necessary.
- Review integrations when you change tools or plans.
Security and privacy
Integrations share customer data between organisations, so treat credentials like passwords, share them only with those who need them and revoke access for tools you no longer use. Consider what personal data each connection moves and whether your privacy notice covers it.
Continue learning
Our guide to integrations, API and reporting shows how these mechanisms support dashboards and attribution, and the glossary entry for webhooks offers a short definition to keep handy.
Keep learning
- Integrations, API & ReportingLearn how APIs, webhooks and integrations connect tools, and how reporting turns connected data into decisions.
- Agency, White-Label & SaaSLearn how sub-accounts, white-label software, templates and reporting help agencies manage many clients.
- Payments & InvoicingLearn how payment links, invoices, checkout and subscriptions work, and how payments update your customer records.