diff --git a/README.md b/README.md
index 153ee56f..21155dd9 100644
--- a/README.md
+++ b/README.md
@@ -41,7 +41,10 @@ A [Telegram bot](https://core.telegram.org/bots/api) that integrates with OpenAI
 - [x] (NEW!) Text-to-speech support [announced on November 6, 2023](https://platform.openai.com/docs/guides/text-to-speech) - by [@gilcu3](https://github.com/gilcu3)
 - [x] (NEW!) Vision support [announced on November 6, 2023](https://platform.openai.com/docs/guides/vision) - by [@gilcu3](https://github.com/gilcu3)
 - [x] (NEW!) GPT-4o model support [announced on May 12, 2024](https://openai.com/index/hello-gpt-4o/) - by [@err09r](https://github.com/err09r)
+- [x] (NEW!) GPT-4.1, gpt-4.1-mini and gpt-4.1-nano model support [(docs)](https://platform.openai.com/docs/models/)
 - [x] (NEW!) o1 and o1-mini model preliminary support
+- [x] (NEW!) o3 and o3-mini model preliminary support
+- [x] (NEW!) o4 and o4-mini model preliminary support
 
 ## Additional features - help needed!
 If you'd like to help, check out the [issues](https://github.com/n3d1117/chatgpt-telegram-bot/issues) section and contribute!  
@@ -94,7 +97,7 @@ Check out the [Budget Manual](https://github.com/n3d1117/chatgpt-telegram-bot/di
 | `PROXY`                             | Proxy to be used for OpenAI and Telegram bot (e.g. `http://localhost:8080`)                                                                                                                                                                                                             | -                                  |
 | `OPENAI_PROXY`                      | Proxy to be used only for OpenAI (e.g. `http://localhost:8080`)                                                                                                                                                                                                                         | -                                  |
 | `TELEGRAM_PROXY`                    | Proxy to be used only for Telegram bot (e.g. `http://localhost:8080`)                                                                                                                                                                                                                   | -                                  |
-| `OPENAI_MODEL`                      | The OpenAI model to use for generating responses. You can find all available models [here](https://platform.openai.com/docs/models/)                                                                                                                                                    | `gpt-4o`                           |
+| `OPENAI_MODEL`                      | The OpenAI model to use for generating responses. You can find all available models [here](https://platform.openai.com/docs/models/)                                                                                                                                                    | `gpt-4.1`                          |
 | `OPENAI_BASE_URL`                   | Endpoint URL for unofficial OpenAI-compatible APIs (e.g., LocalAI or text-generation-webui)                                                                                                                                                                                             | Default OpenAI API URL             |
 | `ASSISTANT_PROMPT`                  | A system message that sets the tone and controls the behavior of the assistant                                                                                                                                                                                                          | `You are a helpful assistant.`     |
 | `SHOW_USAGE`                        | Whether to show OpenAI token usage information after each response                                                                                                                                                                                                                      | `false`                            |
diff --git a/bot/openai_helper.py b/bot/openai_helper.py
index 9fbe5082..93501aca 100644
--- a/bot/openai_helper.py
+++ b/bot/openai_helper.py
@@ -26,8 +26,33 @@
 GPT_4_VISION_MODELS = ("gpt-4o",)
 GPT_4_128K_MODELS = ("gpt-4-1106-preview", "gpt-4-0125-preview", "gpt-4-turbo-preview", "gpt-4-turbo", "gpt-4-turbo-2024-04-09")
 GPT_4O_MODELS = ("gpt-4o", "gpt-4o-mini", "chatgpt-4o-latest")
-O_MODELS = ("o1", "o1-mini", "o1-preview")
-GPT_ALL_MODELS = GPT_3_MODELS + GPT_3_16K_MODELS + GPT_4_MODELS + GPT_4_32K_MODELS + GPT_4_VISION_MODELS + GPT_4_128K_MODELS + GPT_4O_MODELS + O_MODELS
+GPT_4_1_MODELS = (
+    "gpt-4.1",
+    "gpt-4.1-mini",
+    "gpt-4.1-nano",
+)
+O_MODELS = (
+    "o1",
+    "o1-mini",
+    "o1-preview",
+    "o3",
+    "o3-mini",
+    "o3-preview",
+    "o4",
+    "o4-mini",
+    "o4-preview",
+)
+GPT_ALL_MODELS = (
+    GPT_3_MODELS
+    + GPT_3_16K_MODELS
+    + GPT_4_MODELS
+    + GPT_4_32K_MODELS
+    + GPT_4_VISION_MODELS
+    + GPT_4_128K_MODELS
+    + GPT_4O_MODELS
+    + GPT_4_1_MODELS
+    + O_MODELS
+)
 
 def default_max_tokens(model: str) -> int:
     """
@@ -52,6 +77,8 @@ def default_max_tokens(model: str) -> int:
         return 4096
     elif model in GPT_4O_MODELS:
         return 4096
+    elif model in GPT_4_1_MODELS:
+        return 4096
     elif model in O_MODELS:
         return 4096
 
@@ -632,14 +659,14 @@ def __max_model_tokens(self):
             return base * 31
         if self.config['model'] in GPT_4O_MODELS:
             return base * 31
+        if self.config['model'] in GPT_4_1_MODELS:
+            return base * 256  # 1,048,576 token context
         elif self.config['model'] in O_MODELS:
             # https://platform.openai.com/docs/models#o1
-            if self.config['model'] == "o1":
-                return 100_000
-            elif self.config['model'] == "o1-preview":
-                return 32_768
+            if self.config['model'] == "o1-preview":
+                return 128_000
             else:
-                return 65_536
+                return 200_000
         raise NotImplementedError(
             f"Max tokens for model {self.config['model']} is not implemented yet."
         )
@@ -655,7 +682,10 @@ def __count_tokens(self, messages) -> int:
         try:
             encoding = tiktoken.encoding_for_model(model)
         except KeyError:
-            encoding = tiktoken.get_encoding("o200k_base")
+            if model in O_MODELS or model in GPT_4O_MODELS or model in GPT_4_1_MODELS:
+                encoding = tiktoken.get_encoding("o200k_base")
+            else:
+                encoding = tiktoken.get_encoding("cl100k_base")
 
         if model in GPT_ALL_MODELS:
             tokens_per_message = 3