Support claude-sonnet-5 extended thinking in ChatSnowflake

CHANGELOG.md

@@ -12,6 +12,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Bug fixes
 
+* `ChatSnowflake()` now supports Anthropic extended thinking content (e.g. from `claude-sonnet-5`) in both streaming and non-streaming responses. Previously, the thinking deltas sent by Snowflake Cortex raised `ValueError: Unexpected streaming delta type: anthropic`.
+
 * `ChatBedrock()` (with the default `api="converse"`) no longer sends assistant turns with an empty `content` array, which Converse rejects. This happens when a response carries no content blocks, for example when a guardrail intervenes before the model produces any. A `"[empty string]"` placeholder is sent instead, matching how empty text content is already normalized. (#426)
 
 

chatlas/_content_image.py

@@ -156,7 +156,7 @@ def content_image_file(
                 "Install it with `pip install pillow-heif`, or pass "
                 "`resize='none'` to send the original bytes without resizing."
             )
-        pillow_heif.register_heif_opener()
+        pillow_heif.register_heif_opener()  # pyright: ignore[reportPrivateImportUsage]
 
     if resize == "none":
         with open(path, "rb") as image_file:

chatlas/_provider_snowflake.py

@@ -19,6 +19,8 @@
     Content,
     ContentJson,
     ContentText,
+    ContentThinking,
+    ContentThinkingDelta,
     ContentToolRequest,
     ContentToolResult,
 )
@@ -389,7 +391,12 @@ def stream_content(self, chunk, completion, turns=()) -> list[Content]:
         if not chunk.choices:
             return []
         delta = chunk.choices[0].delta
-        if delta is None or "content" not in delta:
+        if delta is None:
+            return []
+        if delta.get("type") == "anthropic":
+            thinking = delta["content_list"][-1]["anthropic"]["thinking"].get("thinking")
+            return [ContentThinkingDelta(thinking=thinking)] if thinking else []
+        if "content" not in delta:
             return []
         return [ContentText.model_construct(text=delta["content"])]
 
@@ -457,6 +464,24 @@ def stream_merge_chunks(self, completion, chunk):
                 # if we don't find it, just append to the end
                 # this shouldn't happen, but just in case
                 content_list.append({"type": "text", "text": text})
+        elif new_delta["type"] == "anthropic":
+            # Extended thinking blocks stream in as a "thinking" fragment
+            # followed by a "signature" fragment, both under the same item.
+            new_thinking = new_content_list[-1]["anthropic"]["thinking"]
+            for i in range(len(content_list) - 1, -1, -1):
+                if content_list[i].get("type") == "anthropic":
+                    thinking = content_list[i]["anthropic"]["thinking"]
+                    if "thinking" in new_thinking:
+                        thinking["thinking"] = (
+                            thinking.get("thinking", "") + new_thinking["thinking"]
+                        )
+                    if "signature" in new_thinking:
+                        thinking["signature"] = (
+                            thinking.get("signature", "") + new_thinking["signature"]
+                        )
+                    break
+            else:
+                content_list.append(new_content_list[-1])
         else:
             raise ValueError(
                 f"Unexpected streaming delta type: {new_delta['type']}. Please report this issue."
@@ -582,6 +607,16 @@ def _as_turn(self, completion: "Completion", has_data_model: bool) -> AssistantT
                     contents.append(ContentJson(value=data))
                 else:
                     contents.append(ContentText(text=content["text"]))
+            elif "anthropic" in content:
+                thinking = content["anthropic"].get("thinking", {})
+                contents.append(
+                    ContentThinking(
+                        thinking=thinking.get("thinking", ""),
+                        extra={"signature": thinking["signature"]}
+                        if "signature" in thinking
+                        else None,
+                    )
+                )
             elif "tool_use_id" in content:
                 params = content.get("input", "{}")
                 try:

chatlas/data/bedrock_apis.json

@@ -10,10 +10,16 @@
   "openai.gpt-5.6-luna": "responses",
   "openai.gpt-5.6-sol": "responses",
   "openai.gpt-5.6-terra": "responses",
+  "openai.gpt-daybreak-blue-5.6-sol": "responses",
   "us-gov-east-1/openai.gpt-5.4": "responses",
+  "us-gov-east-1/xai.grok-4.6": "responses",
+  "us-gov-west-1/google.gemma-4-26b-a4b": "responses",
+  "us-gov-west-1/google.gemma-4-31b": "responses",
+  "us-gov-west-1/google.gemma-4-e2b": "responses",
   "us-gov-west-1/openai.gpt-5.4": "responses",
   "us-gov-west-1/openai.gpt-5.6-luna": "responses",
   "us-gov-west-1/openai.gpt-5.6-terra": "responses",
   "us-gov-west-1/xai.grok-4.3": "responses",
+  "us-gov-west-1/xai.grok-4.6": "responses",
   "xai.grok-4.3": "responses"
 }