Great write-up! Building your own gateway is a great learning experience.
The protocol compatibility point is so important. We spent weeks dealing with subtle differences between Chat Completions, Responses, and Messages formats. Small things like how streaming works, or how tool calls are structured - they all add up.
A few things we learned:
- Start with the OpenAI format as your internal standard. It's the most widely supported. Translate to other protocols on the way out.
- Logging is everything. You need to know exactly which model was called, how many tokens, and what it cost.
- Don't reinvent the wheel. For a lot of use cases, a managed gateway gets you 90% of the way there with 10% of the work.
We ended up using JZS Token as our gateway. It handles all the protocol translation, routing, and logging for us. We just point our tools at one OpenAI-compatible endpoint and have access to 40+ models.
That said, building your own is still a great exercise. You learn a lot about how these systems work under the hood. Good stuff.
Great write-up! Building your own gateway is a great learning experience.
The protocol compatibility point is so important. We spent weeks dealing with subtle differences between Chat Completions, Responses, and Messages formats. Small things like how streaming works, or how tool calls are structured - they all add up.
A few things we learned:
We ended up using JZS Token as our gateway. It handles all the protocol translation, routing, and logging for us. We just point our tools at one OpenAI-compatible endpoint and have access to 40+ models.
That said, building your own is still a great exercise. You learn a lot about how these systems work under the hood. Good stuff.