I have written myself a web fronetend using langchain that uses a json based agent to do advanced tool use (websearch, calculations, document summarisation/information extraction, etc) and chain of thought reasoning. At the moment im using openai gpt-4-turbo for the main agent and gpt-3.5-turbo for some of the summation tools but openai models are limited in capabilities (wont talk about certain topic to the point of disregarding required output json formatting). What service can use that will run a preferably foss model as powerfull as gpt-4 that is pay per use with a langchain integration?

here's the project https://github.com/muntedcrocodile/Sydney

EDIT: Added link to project