Merge pull request #24468 from BerriAI/litellm_opencode-drop-reasoningSummary-docs

docs(opencode): add guidance for dropping reasoningSummary param

Author: yuneng-berri

docs/my-website/docs/tutorials/opencode_integration.md

@@ -253,7 +253,7 @@ model_list:
     litellm_params:
       model: openai/gpt-4
       api_key: os.environ/OPENAI_API_KEY
-  
+
   - model_name: gpt-4o
     litellm_params:
       model: openai/gpt-4o
@@ -264,14 +264,27 @@ model_list:
     litellm_params:
       model: anthropic/claude-3-5-sonnet-20241022
       api_key: os.environ/ANTHROPIC_API_KEY
-  
+
   # DeepSeek models
   - model_name: deepseek-chat
     litellm_params:
       model: deepseek/deepseek-chat
       api_key: os.environ/DEEPSEEK_API_KEY
 ```
 
+### Dropping OpenCode-specific parameters
+
+OpenCode sends a `reasoningSummary` parameter with reasoning-capable models such as `gpt-5`. This parameter is not supported by the Chat Completions API and will cause errors. Add `additional_drop_params` to every model entry in your `model_list` that will receive requests from OpenCode with reasoning enabled:
+
+```yaml
+model_list:
+  - model_name: gpt-5
+    litellm_params:
+      model: openai/gpt-5
+      api_key: os.environ/OPENAI_API_KEY
+      additional_drop_params: ["reasoningSummary"]
+```
+
 ## Troubleshooting
 
 **OpenCode not connecting:**
@@ -294,6 +307,16 @@ model_list:
 - Validate JSON syntax using a JSON validator
 - Ensure the `$schema` URL is accessible
 
+**`Unknown parameter: 'reasoningSummary'` error:**
+- OpenCode sends a `reasoningSummary` parameter that is not supported by the Chat Completions API. Add `additional_drop_params: ["reasoningSummary"]` to each affected model entry in your `litellm_params`:
+  ```yaml
+  - model_name: gpt-5
+    litellm_params:
+      model: openai/gpt-5
+      api_key: os.environ/OPENAI_API_KEY
+      additional_drop_params: ["reasoningSummary"]
+  ```
+
 ## Tips
 
 - Add more models to the config as needed - they'll appear in `/models`