--- title: Creating new Letta presets excerpt: Presets allow you to customize agent functionality category: 6580daaa48aeca0038fc2297 --- Letta **presets** are a combination default settings including a system prompt and a function set. For example, the `letta_docs` preset uses a system prompt that is tuned for document analysis, while the default `memgpt_chat` is tuned for general chatting purposes. You can create your own presets by creating a `.yaml` file in the `~/.letta/presets` directory. If you want to use a new custom system prompt in your preset, you can create a `.txt` file in the `~/.letta/system_prompts` directory. For example, if I create a new system prompt and place it in `~/.letta/system_prompts/custom_prompt.txt`, I can then create a preset that uses this system prompt by creating a new file `~/.letta/presets/custom_preset.yaml`: ```yaml system_prompt: "custom_prompt" functions: - "send_message" - "pause_heartbeats" - "core_memory_append" - "core_memory_replace" - "conversation_search" - "conversation_search_date" - "archival_memory_insert" - "archival_memory_search" ``` This preset uses the same base function set as the default presets. You can see the example presets provided [here](https://github.com/cpacker/Letta/tree/main/letta/presets/examples), and you can see example system prompts [here](https://github.com/cpacker/Letta/tree/main/letta/prompts/system).