diff --git a/buster/completers/base.py b/buster/completers/base.py
index b3fefab..559e834 100644
--- a/buster/completers/base.py
+++ b/buster/completers/base.py
@@ -204,12 +204,6 @@ def from_dict(cls, completion_dict: dict):
 class Completer(ABC):
     """Generic LLM-based completer. Requires a prompt and an input to produce an output."""
 
-    def __init__(
-        self,
-        completion_kwargs: dict,
-    ):
-        self.completion_kwargs = completion_kwargs
-
     @abstractmethod
     def complete(self, prompt: str, user_input) -> (str | Iterator, bool):
         """Returns the completed message (can be a generator), and a boolean to indicate if an error occured or not."""
diff --git a/buster/completers/chatgpt.py b/buster/completers/chatgpt.py
index fb01672..b4a4021 100644
--- a/buster/completers/chatgpt.py
+++ b/buster/completers/chatgpt.py
@@ -1,14 +1,12 @@
 import logging
 import os
-from typing import Iterator
+from typing import Iterator, Optional
 
 import openai
 from openai import OpenAI
 
 from buster.completers import Completer
 
-client = OpenAI()
-
 logger = logging.getLogger(__name__)
 logging.basicConfig(level=logging.INFO)
 
@@ -29,9 +27,19 @@
 
 
 class ChatGPTCompleter(Completer):
+    def __init__(self, completion_kwargs: dict, client_kwargs: Optional[dict] = None):
+        # use default client if none passed
+        self.completion_kwargs = completion_kwargs
+
+        if client_kwargs is None:
+            client_kwargs = {}
+
+        self.client = OpenAI(**client_kwargs)
+
     def complete(self, prompt: str, user_input: str, completion_kwargs=None) -> (str | Iterator, bool):
         """Returns the completed message (can be a generator), and a boolean to indicate if an error occured or not."""
         # Uses default configuration if not overriden
+
         if completion_kwargs is None:
             completion_kwargs = self.completion_kwargs
 
@@ -42,7 +50,7 @@ def complete(self, prompt: str, user_input: str, completion_kwargs=None) -> (str
 
         try:
             error = False
-            response = client.chat.completions.create(messages=messages, **completion_kwargs)
+            response = self.client.chat.completions.create(messages=messages, **completion_kwargs)
         except openai.BadRequestError:
             error = True
             logger.exception("Invalid request to OpenAI API. See traceback:")
diff --git a/buster/documents_manager/base.py b/buster/documents_manager/base.py
index 22b9f86..38a7cf7 100644
--- a/buster/documents_manager/base.py
+++ b/buster/documents_manager/base.py
@@ -5,13 +5,10 @@
 from typing import Optional
 
 import pandas as pd
-from openai import OpenAI
 from tqdm import tqdm
 
 from buster.llm_utils import compute_embeddings_parallelized, get_openai_embedding
 
-client = OpenAI()
-
 tqdm.pandas()
 
 logger = logging.getLogger(__name__)
diff --git a/buster/examples/cfg.py b/buster/examples/cfg.py
index e47422f..42ec66d 100644
--- a/buster/examples/cfg.py
+++ b/buster/examples/cfg.py
@@ -2,10 +2,19 @@
 from buster.completers import ChatGPTCompleter, DocumentAnswerer
 from buster.formatters.documents import DocumentsFormatterJSON
 from buster.formatters.prompts import PromptFormatter
+from buster.llm_utils import get_openai_embedding_constructor
 from buster.retriever import DeepLakeRetriever, Retriever
 from buster.tokenizers import GPTTokenizer
 from buster.validators import Validator
 
+# kwargs to pass to OpenAI client
+client_kwargs = {
+    "timeout": 20,
+    "max_retries": 3,
+}
+
+embedding_fn = get_openai_embedding_constructor(client_kwargs=client_kwargs)
+
 buster_cfg = BusterConfig(
     validator_cfg={
         "question_validator_cfg": {
@@ -15,6 +24,7 @@
                 "stream": False,
                 "temperature": 0,
             },
+            "client_kwargs": client_kwargs,
             "check_question_prompt": """You are a chatbot answering questions on artificial intelligence.
 Your job is to determine wether or not a question is valid, and should be answered.
 More general questions are not considered valid, even if you might know the response.
@@ -35,6 +45,7 @@
                 "I'm sorry, but I am an AI language model trained to assist with questions related to AI. I cannot answer that question as it is not relevant to the library or its usage. Is there anything else I can assist you with?",
             ],
             "unknown_threshold": 0.85,
+            "embedding_fn": embedding_fn,
         },
         "documents_validator_cfg": {
             "completion_kwargs": {
@@ -42,15 +53,16 @@
                 "stream": False,
                 "temperature": 0,
             },
+            "client_kwargs": client_kwargs,
         },
         "use_reranking": True,
-        "validate_documents": True,
+        "validate_documents": False,
     },
     retriever_cfg={
         "path": "deeplake_store",
         "top_k": 3,
         "thresh": 0.7,
-        "embedding_model": "text-embedding-ada-002",
+        "embedding_fn": embedding_fn,
     },
     documents_answerer_cfg={
         "no_documents_message": "No documents are available for this question.",
@@ -61,6 +73,7 @@
             "stream": True,
             "temperature": 0,
         },
+        "client_kwargs": client_kwargs,
     },
     tokenizer_cfg={
         "model_name": "gpt-3.5-turbo",
diff --git a/buster/llm_utils/__init__.py b/buster/llm_utils/__init__.py
index f1c6be2..7588d6c 100644
--- a/buster/llm_utils/__init__.py
+++ b/buster/llm_utils/__init__.py
@@ -2,7 +2,14 @@
     compute_embeddings_parallelized,
     cosine_similarity,
     get_openai_embedding,
+    get_openai_embedding_constructor,
 )
 from buster.llm_utils.question_reformulator import QuestionReformulator
 
-__all__ = [QuestionReformulator, cosine_similarity, get_openai_embedding, compute_embeddings_parallelized]
+__all__ = [
+    QuestionReformulator,
+    cosine_similarity,
+    get_openai_embedding,
+    compute_embeddings_parallelized,
+    get_openai_embedding_constructor,
+]
diff --git a/buster/llm_utils/embeddings.py b/buster/llm_utils/embeddings.py
index 4a91a27..fab5aee 100644
--- a/buster/llm_utils/embeddings.py
+++ b/buster/llm_utils/embeddings.py
@@ -1,32 +1,42 @@
 import logging
 from functools import lru_cache
+from typing import Optional
 
 import numpy as np
 import pandas as pd
 from openai import OpenAI
-from tqdm.contrib.concurrent import process_map
+from tqdm.contrib.concurrent import thread_map
 
 logger = logging.getLogger(__name__)
 logging.basicConfig(level=logging.INFO)
 
-client = OpenAI()
 
+def get_openai_embedding_constructor(client_kwargs: Optional[dict] = None, model: str = "text-embedding-ada-002"):
+    if client_kwargs is None:
+        client_kwargs = {}
+    client = OpenAI(**client_kwargs)
 
-@lru_cache
-def get_openai_embedding(text: str, model: str = "text-embedding-ada-002") -> np.array:
-    try:
-        text = text.replace("\n", " ")
-        response = client.embeddings.create(
-            input=text,
-            model=model,
-        )
-        embedding = response.data[0].embedding
-        return np.array(embedding, dtype="float32")
-    except Exception as e:
-        # This rarely happens with the API but in the off chance it does, will allow us not to loose the progress.
-        logger.exception(e)
-        logger.warning(f"Embedding failed to compute for {text=}")
-        return None
+    @lru_cache
+    def embedding_fn(text: str, model: str = model) -> np.array:
+        try:
+            text = text.replace("\n", " ")
+            response = client.embeddings.create(
+                input=text,
+                model=model,
+            )
+            embedding = response.data[0].embedding
+            return np.array(embedding, dtype="float32")
+        except Exception as e:
+            # This rarely happens with the API but in the off chance it does, will allow us not to loose the progress.
+            logger.exception(e)
+            logger.warning(f"Embedding failed to compute for {text=}")
+            return None
+
+    return embedding_fn
+
+
+# default embedding function
+get_openai_embedding = get_openai_embedding_constructor()
 
 
 def cosine_similarity(a, b):
@@ -50,7 +60,7 @@ def compute_embeddings_parallelized(df: pd.DataFrame, embedding_fn: callable, nu
     """
 
     logger.info(f"Computing embeddings of {len(df)} chunks. Using {num_workers=}")
-    embeddings = process_map(embedding_fn, df.content.to_list(), max_workers=num_workers)
+    embeddings = thread_map(embedding_fn, df.content.to_list(), max_workers=num_workers)
 
     logger.info(f"Finished computing embeddings")
     return embeddings
diff --git a/buster/llm_utils/question_reformulator.py b/buster/llm_utils/question_reformulator.py
index 7b50050..9ce549e 100644
--- a/buster/llm_utils/question_reformulator.py
+++ b/buster/llm_utils/question_reformulator.py
@@ -5,8 +5,13 @@
 
 
 class QuestionReformulator:
-    def __init__(self, system_prompt: Optional[str] = None, completion_kwargs: Optional[dict] = None):
-        self.completer = ChatGPTCompleter(completion_kwargs=completion_kwargs)
+    def __init__(
+        self,
+        system_prompt: Optional[str] = None,
+        completion_kwargs: Optional[dict] = None,
+        client_kwargs: Optional[dict] = None,
+    ):
+        self.completer = ChatGPTCompleter(completion_kwargs=completion_kwargs, client_kwargs=client_kwargs)
 
         if completion_kwargs is None:
             # Default kwargs
diff --git a/buster/retriever/base.py b/buster/retriever/base.py
index 0436ae1..b02ed09 100644
--- a/buster/retriever/base.py
+++ b/buster/retriever/base.py
@@ -2,7 +2,7 @@
 from abc import ABC, abstractmethod
 from dataclasses import dataclass
 from functools import lru_cache
-from typing import Optional
+from typing import Callable, Optional
 
 import numpy as np
 import pandas as pd
@@ -18,10 +18,13 @@
 
 @dataclass
 class Retriever(ABC):
-    def __init__(self, top_k, thresh, embedding_model, *args, **kwargs):
+    def __init__(self, top_k, thresh, embedding_fn: Callable[[str], np.array] = None, *args, **kwargs):
+        if embedding_fn is None:
+            embedding_fn = get_openai_embedding
+
         self.top_k = top_k
         self.thresh = thresh
-        self.embedding_model = embedding_model
+        self.embedding_fn = embedding_fn
 
         # Add your access to documents in your own init
 
@@ -37,11 +40,9 @@ def get_source_display_name(self, source: str) -> str:
         If source is None, returns all documents. If source does not exist, returns empty dataframe."""
         ...
 
-    @staticmethod
-    @lru_cache
-    def get_embedding(query: str, model: str) -> np.ndarray:
+    def get_embedding(self, query: str) -> np.ndarray:
         logger.info("generating embedding")
-        return get_openai_embedding(query, model=model)
+        return self.embedding_fn(query)
 
     @abstractmethod
     def get_topk_documents(self, query: str, source: str = None, top_k: int = None) -> pd.DataFrame:
diff --git a/buster/retriever/deeplake.py b/buster/retriever/deeplake.py
index 236626a..84103e6 100644
--- a/buster/retriever/deeplake.py
+++ b/buster/retriever/deeplake.py
@@ -118,7 +118,7 @@ def get_topk_documents(
         If no matches are found, returns an empty dataframe."""
 
         if query is not None:
-            query_embedding = self.get_embedding(query, model=self.embedding_model)
+            query_embedding = self.get_embedding(query)
         elif embedding is not None:
             query_embedding = embedding
         else:
diff --git a/buster/retriever/service.py b/buster/retriever/service.py
index 38c38b8..78834c8 100644
--- a/buster/retriever/service.py
+++ b/buster/retriever/service.py
@@ -77,7 +77,7 @@ def get_topk_documents(self, query: str, sources: Optional[list[str]], top_k: in
                 logger.warning(f"Sources {sources} do not exist. Returning empty dataframe.")
                 return pd.DataFrame()
 
-        query_embedding = self.get_embedding(query, model=self.embedding_model)
+        query_embedding = self.get_embedding(query)
 
         if isinstance(query_embedding, np.ndarray):
             # pinecone expects a list of floats, so convert from ndarray if necessary
diff --git a/buster/validators/validators.py b/buster/validators/validators.py
index 93336c6..be6a467 100644
--- a/buster/validators/validators.py
+++ b/buster/validators/validators.py
@@ -19,7 +19,7 @@ def __init__(
         check_question_prompt: Optional[str] = None,
         invalid_question_response: Optional[str] = None,
         completion_kwargs: Optional[dict] = None,
-        completer: Optional[Completer] = None,
+        client_kwargs: Optional[dict] = None,
     ):
         if check_question_prompt is None:
             check_question_prompt = (
@@ -39,10 +39,8 @@ def __init__(
 A user will submit a question. Respond 'true' if it is valid, respond 'false' if it is invalid.""",
             )
 
-        if completer is None:
-            completer = ChatGPTCompleter
-
         if completion_kwargs is None:
+            # default completion kwargs
             completion_kwargs = (
                 {
                     "model": "gpt-3.5-turbo",
@@ -51,7 +49,7 @@ def __init__(
                 },
             )
 
-        self.completer = completer(completion_kwargs=completion_kwargs)
+        self.completer = ChatGPTCompleter(completion_kwargs=completion_kwargs, client_kwargs=client_kwargs)
         self.check_question_prompt = check_question_prompt
         self.invalid_question_response = invalid_question_response
 
@@ -117,6 +115,7 @@ class DocumentsValidator:
     def __init__(
         self,
         completion_kwargs: Optional[dict] = None,
+        client_kwargs: Optional[dict] = None,
         system_prompt: Optional[str] = None,
         user_input_formatter: Optional[str] = None,
         max_calls: int = 30,
@@ -144,7 +143,7 @@ def __init__(
                 "temperature": 0,
             }
 
-        self.completer = ChatGPTCompleter(completion_kwargs=completion_kwargs)
+        self.completer = ChatGPTCompleter(completion_kwargs=completion_kwargs, client_kwargs=client_kwargs)
 
         self.max_calls = max_calls
 
diff --git a/tests/test_chatbot.py b/tests/test_chatbot.py
index a074b5b..a0ed267 100644
--- a/tests/test_chatbot.py
+++ b/tests/test_chatbot.py
@@ -30,6 +30,10 @@
             "model": "gpt-3.5-turbo",
             "temperature": 0,
         },
+        "client_kwargs": {
+            "timeout": 20,
+            "max_retries": 2,
+        },
     },
     validator_cfg={
         "validate_documents": False,
@@ -47,6 +51,10 @@
                 "stream": False,
                 "temperature": 0,
             },
+            "client_kwargs": {
+                "timeout": 20,
+                "max_retries": 2,
+            },
             "check_question_prompt": "You are validating if questions are related to AI. If a question is relevant, respond with 'true', if it is irrlevant, respond with 'false'.",
         },
     },