diff --git a/packages/opencode/src/provider/transform.ts b/packages/opencode/src/provider/transform.ts
index b388297aee8..0667fc2eb09 100644
--- a/packages/opencode/src/provider/transform.ts
+++ b/packages/opencode/src/provider/transform.ts
@@ -1303,13 +1303,13 @@ export function options(input: {
       }
     }
 
-    // Only set textVerbosity for non-chat gpt-5.x models
-    // Chat models (e.g. gpt-5.2-chat-latest) only support "medium" verbosity
+    // Generic OpenAI-compatible APIs do not necessarily support OpenAI's verbosity parameter.
+    // Only enable the default for integrations known to implement it.
     if (
       input.model.api.id.includes("gpt-5.") &&
       !input.model.api.id.includes("codex") &&
       !input.model.api.id.includes("-chat") &&
-      input.model.providerID !== "azure"
+      (input.model.api.npm === "@ai-sdk/openai" || input.model.api.npm === "@ai-sdk/amazon-bedrock/mantle")
     ) {
       result["textVerbosity"] = "low"
     }
diff --git a/packages/opencode/test/provider/transform.test.ts b/packages/opencode/test/provider/transform.test.ts
index 77aa38ad73a..97f0de28148 100644
--- a/packages/opencode/test/provider/transform.test.ts
+++ b/packages/opencode/test/provider/transform.test.ts
@@ -523,6 +523,7 @@ describe("ProviderTransform.options - gpt-5 textVerbosity", () => {
     expect(result.reasoningEffort).toBe("medium")
     expect(result.reasoningSummary).toBeUndefined()
     expect(result.include).toBeUndefined()
+    expect(result.textVerbosity).toBeUndefined()
   })
 
   test("azure chat completions omit Responses-only reasoning options after variants merge", async () => {