From 8c9442ad11691004278607d83a4205807c644e82 Mon Sep 17 00:00:00 2001
From: Umesh Yadav <23421535+imumesh18@users.noreply.github.com>
Date: Sat, 6 Sep 2025 10:46:08 +0530
Subject: [PATCH] language_models: Skip empty delta text content in OpenAI and
 OpenAI compatible provider (#37626)

Closes #37302

Related: #37614

In case of open_ai_compatible providers like Zhipu AI and z.ai they
return empty content along with usage data. below is the example json
captured from z.ai. We now ignore empty content returned by providers
now to avoid this issue where we would return the same empty content
back to provider which would error out.

```
OpenAI Stream Response JSON:
{
  "id": "2025090518465610d80dc21e66426d",
  "created": 1757069216,
  "model": "glm-4.5",
  "choices": [
    {
      "index": 0,
      "finish_reason": "tool_calls",
      "delta": {
        "role": "assistant",
        "content": ""
      }
    }
  ],
  "usage": {
    "prompt_tokens": 7882,
    "completion_tokens": 150,
    "total_tokens": 8032,
    "prompt_tokens_details": {
      "cached_tokens": 7881
    }
  }
}
```

Release Notes:

- Skip empty delta text content in OpenAI and OpenAI compatible provider

Signed-off-by: Umesh Yadav <git@umesh.dev>
---
 crates/language_models/src/provider/open_ai.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/crates/language_models/src/provider/open_ai.rs b/crates/language_models/src/provider/open_ai.rs
index 4348fd42110b2554de801b812a7b001dc49ad06e..cfd43033515e2c3527c8d0dfbf1267fb96793819 100644
--- a/crates/language_models/src/provider/open_ai.rs
+++ b/crates/language_models/src/provider/open_ai.rs
@@ -586,7 +586,9 @@ impl OpenAiEventMapper {
         };
 
         if let Some(content) = choice.delta.content.clone() {
-            events.push(Ok(LanguageModelCompletionEvent::Text(content)));
+            if !content.is_empty() {
+                events.push(Ok(LanguageModelCompletionEvent::Text(content)));
+            }
         }
 
         if let Some(tool_calls) = choice.delta.tool_calls.as_ref() {