diff --git a/ldai/client.py b/ldai/client.py
index 0312096..90218e2 100644
--- a/ldai/client.py
+++ b/ldai/client.py
@@ -2,12 +2,14 @@
 from typing import Any, Dict, List, Literal, Optional
 
 import chevron
+from dataclasses_json import dataclass_json
 from ldclient import Context
 from ldclient.client import LDClient
 
 from ldai.tracker import LDAIConfigTracker
 
 
+@dataclass_json
 @dataclass
 class LDMessage:
     role: Literal['system', 'user', 'assistant']
@@ -59,7 +61,7 @@ def model_config(
         if isinstance(variation['prompt'], list) and all(
             isinstance(entry, dict) for entry in variation['prompt']
         ):
-            variation['prompt'] = [
+            prompt = [
                 LDMessage(
                     role=entry['role'],
                     content=self.__interpolate_template(
@@ -71,7 +73,7 @@ def model_config(
 
         enabled = variation.get('_ldMeta', {}).get('enabled', False)
         return AIConfig(
-            config=AIConfigData(model=variation['model'], prompt=variation['prompt']),
+            config=AIConfigData(model=variation['model'], prompt=prompt),
             tracker=LDAIConfigTracker(
                 self.client,
                 variation.get('_ldMeta', {}).get('versionKey', ''),
diff --git a/pyproject.toml b/pyproject.toml
index c03027d..0b86b18 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -27,11 +27,12 @@ exclude = [
 ]
 
 [tool.poetry.dependencies]
-python = ">=3.8"
+python = ">=3.8,<4"
 launchdarkly-server-sdk = ">=9.4.0"
 chevron = "=0.14.0"
 pycodestyle = "^2.12.1"
 isort = "^5.13.2"
+dataclasses-json = "^0.6.7"
 
 
 [tool.poetry.group.dev.dependencies]