Question: I'm looking for an API client that integrates design, testing, and team collaboration features in one place.

If you're looking for an API client that combines design, testing and team collaboration in one package, ApyHub Fusion is a good all-in-one option. It includes a visual API design and development editor, API testing with code previews and automated test generation, API documentation with AI-boosted generation, and mock servers. The service also handles team collaboration with private workspaces and in-line commenting, so it's good for developers and teams. It also has a free tier and "pay as you grow" pricing.

Another good option is ReAPI, which uses AI and ChatGPT to help with API design, testing and documentation. It includes a no-code test case designer, a serverless cloud runner, and a detailed test report. ReAPI also offers collaboration abilities with internal and external sharing, versioning and permission controls, and automated API documentation generation that's visually appealing and easy to read.

If you want to concentrate more on designing B2B integrations, Conektto is a powerful platform with AI-boosted tools for API design, testing and deployment. It includes APIs Design Studio, API Test Harness and an Enterprise API SDLC, which should make it easier and faster for product managers, architects, developers, testers and DevOps teams to handle API development.

Last, SmartBear offers a collection of tools designed to help with software development, monitoring and testing. With products like SwaggerHub and PactFlow for API design and testing, and TestComplete and Zephyr Enterprise for test automation, SmartBear's tools are flexible and accessible, letting customers start small and scale up as needed. The company's tools also integrate with widely used development tools and frameworks, so it's good for big projects and enterprise environments.