Using OpenAI via Cloudflare AI Gateway results in Unsupported parameter error. #22374

Description

When using /models to pick a GPT model like GPT-5.4 or some other modern OpenAI model you get the following result from any prompt: Unsupported parameter: 'max_tokens' is not supported with this model. Use 'max_completion_tokens' instead.

If you use an older GPT model like GPT-4o does work. I think this has to do with "OpenAI officially switched to max_completion_tokens in September 2024 to coincide with the release of the o1 series models"

Curious if there is a plan to fix or a best workaround.

Plugins

No response

OpenCode version

1.3.10

Steps to reproduce

After making sure you set up Cloudflare AI Gateway and a model like Claude Opus 4.6 works

1. opencode
2. /models
3. GPT-5.4 Cloudflare AI Gateway
4. Get error.

Screenshot and/or share link

Operating System

macOS 26.4.1

Terminal

macos terminal