fix(bedrock.py): fix amazon titan prompt formatting

litellm/llms/bedrock.py

@@ -477,8 +477,8 @@ def init_bedrock_client(
 
 
 def convert_messages_to_prompt(model, messages, provider, custom_prompt_dict):
-    # handle anthropic prompts using anthropic constants
+    # handle anthropic prompts and amazon titan prompts
-    if provider == "anthropic":
+    if provider == "anthropic" or provider == "amazon":
         if model in custom_prompt_dict:
             # check if the model has a registered custom prompt
             model_prompt_details = custom_prompt_dict[model]
@@ -490,7 +490,7 @@ def convert_messages_to_prompt(model, messages, provider, custom_prompt_dict):
             )
         else:
             prompt = prompt_factory(
-                model=model, messages=messages, custom_llm_provider="anthropic"
+                model=model, messages=messages, custom_llm_provider="bedrock"
             )
     else:
         prompt = ""
@@ -623,6 +623,7 @@ def completion(
                     "textGenerationConfig": inference_params,
                 }
             )
+
         else:
             data = json.dumps({})
 

litellm/llms/prompt_templates/factory.py

@@ -90,9 +90,11 @@ def ollama_pt(
         return {"prompt": prompt, "images": images}
     else:
         prompt = "".join(
+            (
                 m["content"]
                 if isinstance(m["content"], str) is str
                 else "".join(m["content"])
+            )
             for m in messages
         )
     return prompt
@@ -422,6 +424,34 @@ def anthropic_pt(
     return prompt
 
 
+def amazon_titan_pt(
+    messages: list,
+):  # format - https://github.com/BerriAI/litellm/issues/1896
+    """
+    Amazon Titan uses 'User:' and 'Bot: in it's prompt template
+    """
+
+    class AmazonTitanConstants(Enum):
+        HUMAN_PROMPT = "\n\nUser: "  # Assuming this is similar to Anthropic prompt formatting, since amazon titan's prompt formatting is currently undocumented
+        AI_PROMPT = "\n\nBot: "
+
+    prompt = ""
+    for idx, message in enumerate(messages):
+        if message["role"] == "user":
+            prompt += f"{AmazonTitanConstants.HUMAN_PROMPT.value}{message['content']}"
+        elif message["role"] == "system":
+            prompt += f"{AmazonTitanConstants.HUMAN_PROMPT.value}<admin>{message['content']}</admin>"
+        else:
+            prompt += f"{AmazonTitanConstants.AI_PROMPT.value}{message['content']}"
+        if (
+            idx == 0 and message["role"] == "assistant"
+        ):  # ensure the prompt always starts with `\n\nHuman: `
+            prompt = f"{AmazonTitanConstants.HUMAN_PROMPT.value}" + prompt
+    if messages[-1]["role"] != "assistant":
+        prompt += f"{AmazonTitanConstants.AI_PROMPT.value}"
+    return prompt
+
+
 def _load_image_from_url(image_url):
     try:
         from PIL import Image
@@ -636,6 +666,14 @@ def prompt_factory(
             return gemini_text_image_pt(messages=messages)
     elif custom_llm_provider == "mistral":
         return mistral_api_pt(messages=messages)
+    elif custom_llm_provider == "bedrock":
+        if "amazon.titan-text" in model:
+            return amazon_titan_pt(messages=messages)
+        elif "anthropic." in model:
+            if any(_ in model for _ in ["claude-2.1", "claude-v2:1"]):
+                return claude_2_1_pt(messages=messages)
+            else:
+                return anthropic_pt(messages=messages)
     try:
         if "meta-llama/llama-2" in model and "chat" in model:
             return llama_2_chat_pt(messages=messages)