Description

when I use @ai-sdk/openai-compatible to create a provider, and ues the GPT 5.x model, the body of the request contains max_tokens, not max_completion_tokens, so the LLM returned an error as below:

ERROR 2025-12-12T05:44:36 +2ms service=session.processor error=Unsupported parameter: 'max_tokens' is not supported with this model. Use 'max_completion_tokens' instead. stack="AI_APICallError: Unsupported parameter: 'max_tokens' is not supported with this model. Use 'max_completion_tokens' instead.\n at <anonymous> (/Users/mtk/AI_Coding/OSS/opencode/node_modules/.bun/@[email protected]+d6123d32214422cb/node_modules/@ai-sdk/provider-utils/dist/index.mjs:889:18)\n at processTicksAndRejections (native:7:39)" process

I find the ’max_tokens‘ is deprecated in the openai API reference for reasoning models.
https://platform.openai.com/docs/api-reference/chat/create#chat_create-max_tokens

My provider as below

"gaisf-openai-compatible": { "npm": "@ai-sdk/openai-compatible", "name": "gaisf-openai-compatible", "options": { "baseURL": "https://mlop-azure-gateway.xxxx.inc/v1", "apiKey": "{env:MY_GAISF_KEY}", "timeout": 300000 }, "models": { "gpt-5.1-high": { "id": "azure/gpt-5.1", "name": "gpt-5.1-high-test", "attachment": true, "modalities": { "input": ["text", "image"], "output": ["text"] }, "options": { "reasoningEffort": "high" }, "limit": { "context": 400000, "output": 128000 }, "cost": { "input": 1.25, "output": 10, "cache_read": 0.13 } } }

@rekram1-node Could you help to check this issue?

OpenCode version

1.0.150

Steps to reproduce

use @ai-sdk/openai-compatible for gpt 5.x model to create provider

Screenshot and/or share link

NA

Operating System

ubuntu 24.4

Terminal

VSCode remoteSSH