Question: Are there any ChatGPT integrations that support advanced models like GPT-4 and Claude 3 Opus?

Halist AI offers fast and private access to ChatGPT models on the web, mobile, desktop and Chrome. It supports multiple platforms and can use OpenAI GPT-3, GPT-4 and Anthropic Claude 3 Opus to generate useful responses. Halist offers several pricing levels, including a free tier and a pro tier for unlimited fair usages per month with GPT-4 and Claude 3 Opus models.

Another top contender is Anthropic, which offers Claude as a more advanced AI assistant for tasks like conversational interactions, data processing and code generation. Claude comes with more advanced models like Haiku, Sonnet and Opus, the latter of which is geared for heavy processing and high-order math. Pricing ranges from a free version to a Team plan, and the Claude API is available for developers.

If you want a Chrome extension, HARPA lets you automate websites with AI models like ChatGPT, GPT-3, GPT-4, Claude2 and others. It has more than 100 web-aware commands across many domains, and you can turn it on for any website with an Alt + A keyboard shortcut. HARPA offers several pricing tiers, including a free version and subscription plans.

Last, ChatBotKit is a service for building AI chatbots that supports multiple interfaces and foundational models including GPT-4, Claude 3 and Mistral Large. It comes with a variety of tools like a coding assistant, custom datasets and webhooks, so it should work for a lot of use cases. ChatBotKit has four pricing tiers, including options for developers and nondevelopers.