[Feature]Supports Anthropic Thinking Block (#33671)

Signed-off-by: mariohong <mariohong128@gmail.com>
Co-authored-by: zetaohong <i-hongzetao@stepfun.com>
Co-authored-by: Chauncey <chaunceyjiang@gmail.com>

vllm/entrypoints/anthropic/protocol.py

@@ -34,7 +34,7 @@ class AnthropicUsage(BaseModel):
 class AnthropicContentBlock(BaseModel):
     """Content block in message"""
 
-    type: Literal["text", "image", "tool_use", "tool_result"]
+    type: Literal["text", "image", "tool_use", "tool_result", "thinking"]
     text: str | None = None
     # For image content
     source: dict[str, Any] | None = None
@@ -45,6 +45,9 @@ class AnthropicContentBlock(BaseModel):
     input: dict[str, Any] | None = None
     content: str | list[dict[str, Any]] | None = None
     is_error: bool | None = None
+    # For thinking content
+    thinking: str | None = None
+    signature: str | None = None
 
 
 class AnthropicMessage(BaseModel):
@@ -118,9 +121,14 @@ class AnthropicMessagesRequest(BaseModel):
 class AnthropicDelta(BaseModel):
     """Delta for streaming responses"""
 
-    type: Literal["text_delta", "input_json_delta"] | None = None
+    type: (
+        Literal["text_delta", "input_json_delta", "thinking_delta", "signature_delta"]
+        | None
+    ) = None
     text: str | None = None
+    thinking: str | None = None
     partial_json: str | None = None
+    signature: str | None = None
 
     # Message delta
     stop_reason: (