add AI/ML API as provider

[OctavianTheI]

Hi!

I'm Sergey from the Integrations team over at AI/ML API, a startup with 150K+ users, providing over 300 AI models in one place

Your project looks dope, so we'd like a native integration. We already got integrations with Langflow, AutoGPT, and LiteLLM - so our integrations team is pretty seasoned :)

Say you're interested, and we'll test the compatibility, update the code/docs to include us, create a PR and add a tutorial on using haystack with AI/ML API to our docs

If you guys give us a green light, we could get on it next week 👷

[julian-risch]

Hi @OctavianTheI Thank you for reaching out! We'd appreciate an integration with AI/ML API! 🟢

Before you get started, let me explain that there are two main options for creating an integration. It's your choice.

1. You create the integration in one of your own repositories. Then you own the repo, code changes don't need to go through our review process but we're happy to provide feedback, you can trigger new releases yourselves and move at your own speed.
2. You open a PR in the haystack-core-integrations repository. The code base and the pypi package are then with us, we are the ones who trigger new releases. We'd still rely on your support to keep the integration up to date, in particular if there are breaking changes in your interfaces. Long-term support of the integration, robustness, maintenance and nightly tests are important to us and our users.

We will list the integration on our web page https://haystack.deepset.ai/integrations in both cases and make sure the integration gets great visibility! Tutorial sounds great of course too!

Given compatibility of AI/ML API with the OpenAI SDK, you can get inspiration for your integration from Haystack's OpenAIChatGenerator and a couple of integrations that have ChatGenerator components that inherit from OpenAIChatGenerator. For example MistralChatGenerator or OpenRouterChatGenerator and PRs where we added those integrations.
Guidelines for new contributors can be found here and don't hesitate to ask if you have questions!

[mpangrazzi]

@julian-risch this should be closed after merging #2267

[julian-risch]

Merged #2267
Follow up issue about docs and social media announcement is here: #2349