release initial code

Co-authored-by: Ying Sheng <sqy1415@gmail.com>
Co-authored-by: Liangsheng Yin <hnyls2002@gmail.com>
Co-authored-by: Zhiqiang Xie <xiezhq@stanford.edu>
Co-authored-by: parasol-aser <3848358+parasol-aser@users.noreply.github.com>
Co-authored-by: LiviaSun <33578456+ChuyueSun@users.noreply.github.com>
Co-authored-by: Cody Yu <hao.yu.cody@gmail.com>

python/sglang/backend/anthropic.py

@@ -0,0 +1,57 @@
+from typing import List, Optional, Union
+
+import numpy as np
+from sglang.backend.base_backend import BaseBackend
+from sglang.lang.chat_template import get_chat_template
+from sglang.lang.interpreter import StreamExecutor
+from sglang.lang.ir import SamplingParams
+
+try:
+    import anthropic
+except ImportError as e:
+    anthropic = e
+
+
+class Anthropic(BaseBackend):
+    def __init__(self, model_name):
+        super().__init__()
+
+        if isinstance(anthropic, Exception):
+            raise anthropic
+
+        self.model_name = model_name
+        self.chat_template = get_chat_template("claude")
+
+    def get_chat_template(self):
+        return self.chat_template
+
+    def generate(
+        self,
+        s: StreamExecutor,
+        sampling_params: SamplingParams,
+    ):
+        prompt = s.text_
+        ret = anthropic.Anthropic().completions.create(
+            model=self.model_name,
+            prompt=prompt,
+            **sampling_params.to_anthropic_kwargs(),
+        )
+        comp = ret.completion
+
+        return comp, {}
+
+    def generate_stream(
+        self,
+        s: StreamExecutor,
+        sampling_params: SamplingParams,
+    ):
+        prompt = s.text_
+        generator = anthropic.Anthropic().completions.create(
+            model=self.model_name,
+            prompt=prompt,
+            stream=True,
+            **sampling_params.to_anthropic_kwargs(),
+        )
+
+        for ret in generator:
+            yield ret.completion, {}