[GTM glossary](/glossary.md) API Data & Enrichment # API (API) Also known as: application programming interface In short An API, or application programming interface, is a set of rules that lets one software system request data or trigger actions in another. The request and response follow a documented format, so tools can talk to each other without a person in between. In go-to-market work, APIs move data between your CRM, enrichment sources, marketing automation, and data warehouse, and they let teams automate tasks that would otherwise be manual exports and uploads. ## How an API works A client sends a request to an endpoint, a specific URL. The server checks credentials, does the work, and returns a response, usually in JSON. * **Endpoint:** The address for a resource, such as companies or contacts. * **Method:** The action: read (GET), create (POST), update (PUT or PATCH), or delete (DELETE). * **Authentication:** An API key or token proves who is calling. * **Rate limit:** A cap on requests per minute or day, to protect the service. --- ## Common API uses in GTM * **Enrichment:** Send a domain, receive company fields back. * **CRM sync:** Create and update records when something changes elsewhere. * **Lead routing:** Push new form fills to the right owner within seconds. * **Reporting:** Pull data into a warehouse or dashboard. --- ## API vs. native integration A native integration is a prebuilt connector between two products. An API is the underlying interface you can use to build your own connection. Use native integrations for standard needs and an API when you need custom logic, volume, or fields the connector does not cover. --- ## Practical tips ### Read the docs first Check endpoints, field names, pagination, and limits before planning a build. ### Handle errors and retries Calls fail. Log failures and retry with a delay instead of dropping records. ### Protect keys Store keys in a secrets manager, never in shared spreadsheets or code repositories. ### Test with a small batch Confirm field mapping on a handful of records before a full run. --- ## Common mistakes * **Ignoring rate limits:** Bursts of calls get blocked and records go missing. * **No monitoring:** A silent failure can leave data out of sync for weeks. * **Overwriting good data:** Unclear update rules let a sync replace correct values with blanks. --- ## API FAQs **What is an API in simple terms?** An API is a set of rules that lets one piece of software ask another for data or to perform an action. You can think of it as a waiter between systems: it takes a request, gets the result, and brings it back in a standard format. **What is an API used for in sales and marketing?** In sales and marketing, APIs connect tools so data moves automatically. Common uses include enriching records, syncing contacts between a CRM and marketing platform, routing leads, and sending data to a warehouse for reporting. **What is the difference between an API and an integration?** An integration is a working connection between two tools, while an API is the interface that makes such connections possible. Some integrations are prebuilt connectors; others are custom builds that call an API directly. **What is an API key?** An API key is a secret string that identifies the application or user making API requests and lets the provider authorize and track usage. Keep it private, rotate it if exposed, and never store it in shared documents or public code. Share term --- ## More related phrases * [Web scraping](/glossary/web-scraping.md) * [Data pipeline](/glossary/data-pipeline.md) * [ETL](/glossary/etl.md) ## Similar phrases * [Enrichment API](/glossary/enrichment-api.md) An enrichment API lets your own systems send a record, such as an email or domain, and receive additional data back programmatically, instead of using a manual upload or a point-and-click tool. * [Custom API integration](/glossary/custom-api-integration.md) A custom API integration is a purpose-built connection, coded against two systems’ APIs, that moves data between them according to your own business rules when off-the-shelf connectors fall short. * [Webhooks](/glossary/webhooks.md) Webhooks are automated messages one application sends to another the moment an event happens, letting GTM tools share data in real time without constant polling. * [CRM integration](/glossary/crm-integration.md) CRM integration connects your customer relationship management system with other tools, such as marketing automation, data providers, and sales engagement, so records and activity sync automatically between them. * [Native integration](/glossary/native-integration.md) A native integration is a built-in, vendor-maintained connection between two software products that syncs data without custom code or a third-party middleware tool.