Add Anthropic prefill messages

.env.example

@@ -2,8 +2,9 @@ AZURE_OPENAI_API_KEY=YOURKEY
 AZURE_OPENAI_ENDPOINT=https://YOURENDPOINT.openai.azure.com
 AZURE_OPENAI_API_VERSION=2024-02-01
 MODEL=gpt-4o-mini
+ANTHROPIC_PREFILL_PROMPT={
 EMBEDDING=text-embedding-3-small
 EMBEDDING_MODEL_MAX_TOKENS=8192
 GITHUB_TOKEN=YOURTOKEN
 SUPABASE_URL=https://YOURLINK.supabase.co
-SUPABASE_KEY=your_supabase_key
+SUPABASE_KEY=your_supabase_key

README.md

@@ -56,6 +56,7 @@ To run this project in Daytona, you'll need to have Daytona installed. Follow th
     AZURE_OPENAI_API_KEY=your_azure_openai_api_key
     AZURE_OPENAI_API_VERSION=your_azure_openai_api_version
     MODEL=your_model_name
+    ANTHROPIC_PREFILL_PROMPT=optional_prefill_for_claude_models
     GITHUB_TOKEN=your_github_token
     ```
 
@@ -85,6 +86,7 @@ AZURE_OPENAI_ENDPOINT=your_azure_openai_endpoint
 AZURE_OPENAI_API_KEY=your_azure_openai_api_key
 AZURE_OPENAI_API_VERSION=your_azure_openai_api_version
 MODEL=your_model_name
+ANTHROPIC_PREFILL_PROMPT=optional_prefill_for_claude_models
 GITHUB_TOKEN=your_github_token
 ```
 
@@ -128,4 +130,4 @@ This project is licensed under the MIT License. See the [LICENSE](LICENSE) file
 
 ---
 
-Thank you for using **devcontainer-generator**! If you have any questions or issues, feel free to open an issue on GitHub.
+Thank you for using **devcontainer-generator**! If you have any questions or issues, feel free to open an issue on GitHub.

helpers/devcontainer_helpers.py

@@ -6,6 +6,7 @@
 import jsonschema
 import tiktoken
 from helpers.jinja_helper import process_template
+from helpers.llm_message_helpers import build_devcontainer_messages
 from schemas import DevContainerModel
 from supabase_client import supabase
 from models import DevContainer
@@ -92,10 +93,7 @@ def generate_devcontainer_json(instructor_client, repo_url, repo_context, devcon
             response = instructor_client.chat.completions.create(
                 model=os.getenv("MODEL"),
                 response_model=DevContainerModel,
-                messages=[
-                    {"role": "system", "content": "You are a helpful assistant that generates devcontainer.json files."},
-                    {"role": "user", "content": prompt},
-                ],
+                messages=build_devcontainer_messages(prompt, os.getenv("MODEL")),
             )
             devcontainer_json = json.dumps(response.dict(exclude_none=True), indent=2)
 
@@ -136,4 +134,4 @@ def save_devcontainer(new_devcontainer):
         return result.data[0] if result.data else None
     except Exception as e:
         logging.error(f"Error saving devcontainer to Supabase: {str(e)}")
-        raise
+        raise

helpers/llm_message_helpers.py

@@ -0,0 +1,37 @@
+import os
+
+
+ANTHROPIC_PREFILL_ENV_VAR = "ANTHROPIC_PREFILL_PROMPT"
+DEFAULT_ANTHROPIC_PREFILL_PROMPT = "{"
+
+
+def is_anthropic_model(model_name):
+    if not model_name:
+        return False
+
+    normalized_model = model_name.strip().lower()
+    return normalized_model.startswith("claude") or (
+        "anthropic" in normalized_model and "claude" in normalized_model
+    )
+
+
+def get_anthropic_prefill_prompt():
+    configured_prefill = os.getenv(ANTHROPIC_PREFILL_ENV_VAR, DEFAULT_ANTHROPIC_PREFILL_PROMPT)
+    return configured_prefill.strip() or DEFAULT_ANTHROPIC_PREFILL_PROMPT
+
+
+def build_devcontainer_messages(prompt, model_name=None):
+    messages = [
+        {"role": "system", "content": "You are a helpful assistant that generates devcontainer.json files."},
+        {"role": "user", "content": prompt},
+    ]
+
+    if is_anthropic_model(model_name):
+        messages.append(
+            {
+                "role": "assistant",
+                "content": get_anthropic_prefill_prompt(),
+            }
+        )
+
+    return messages

tests/test_llm_message_helpers.py

@@ -0,0 +1,40 @@
+import os
+import unittest
+from unittest.mock import patch
+
+from helpers.llm_message_helpers import build_devcontainer_messages, is_anthropic_model
+
+
+class LlmMessageHelpersTest(unittest.TestCase):
+    def test_non_anthropic_models_keep_original_messages(self):
+        messages = build_devcontainer_messages("render this prompt", "gpt-4o-mini")
+
+        self.assertEqual(
+            messages,
+            [
+                {"role": "system", "content": "You are a helpful assistant that generates devcontainer.json files."},
+                {"role": "user", "content": "render this prompt"},
+            ],
+        )
+
+    def test_anthropic_models_add_default_prefill(self):
+        messages = build_devcontainer_messages("render this prompt", "claude-3-5-sonnet-20241022")
+
+        self.assertEqual(messages[-1], {"role": "assistant", "content": "{"})
+        self.assertEqual(len(messages), 3)
+
+    def test_anthropic_prefill_can_be_overridden(self):
+        with patch.dict(os.environ, {"ANTHROPIC_PREFILL_PROMPT": '{"name":'}, clear=False):
+            messages = build_devcontainer_messages("render this prompt", "anthropic/claude-3-haiku")
+
+        self.assertEqual(messages[-1], {"role": "assistant", "content": '{"name":'})
+
+    def test_anthropic_model_detection_requires_claude_context(self):
+        self.assertTrue(is_anthropic_model("claude-3-opus"))
+        self.assertTrue(is_anthropic_model("anthropic/claude-3-haiku"))
+        self.assertFalse(is_anthropic_model("gpt-4o-mini"))
+        self.assertFalse(is_anthropic_model("some-anthropic-compatible-model"))
+
+
+if __name__ == "__main__":
+    unittest.main()