Insightly is a CRM platform that assists businesses, particularly small to medium-sized ones, in managing relationships, sales, projects, and tasks within a centralized system, and offers further value when integrated with other products or internal applications via its API. To access the API key required for integration, users must log in, navigate to the user settings, and locate the API section. Insightly provides different pricing plans, including a free version, and enforces rate limits to prevent API abuse, which vary depending on the chosen plan level. Common API error messages include data validation errors and authentication failures, among others. Merge offers a unified API platform that facilitates integration with various CRM tools, such as Hubspot and Salesforce, and provides a comprehensive integration management solution.