> ## Documentation Index
> Fetch the complete documentation index at: https://docs.memobase.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Profile Fundamentals

Memobase serves as a [user profile backend](/features#user-profile-as-memory) for LLM applications, enabling them to track and update specific user attributes over time.

<Frame caption="A sample user profile in Memobase, showing structured data slots.">
  <img src="https://mintcdn.com/memobase/YiZ2SowwPcUyIWD4/images/profile_demo.png?fit=max&auto=format&n=YiZ2SowwPcUyIWD4&q=85&s=a61aa124f626c06ebe24d1bb648a30f0" width="3973" height="2527" data-path="images/profile_demo.png" />
</Frame>

By default, Memobase includes a set of built-in profile slots for common use cases, but it also offers full customization to control the specific memories your application collects.

### Locating the `config.yaml` File

Memobase uses a `config.yaml` file for backend configuration. You can find this file at `src/server/api/config.yaml` in your self-hosted instance. A typical configuration looks like this:

```yaml theme={null}
max_chat_blob_buffer_token_size: 1024
buffer_flush_interval: 3600
llm_api_key: sk-...
best_llm_model: gpt-4o-mini
# ... other settings
```

## Understanding Profile Slots

Memobase comes with a default schema of profile slots, such as:

```markdown theme={null}
- basic_info
    - name
    - gender
- education
    - school
    - major
```

You can extend this schema by adding custom slots under the `additional_user_profiles` field in `config.yaml`:

```yaml theme={null}
additional_user_profiles:
    - topic: "Gaming"
      description: "Tracks the user's gaming preferences and achievements."
      sub_topics:
        - name: "FPS"
          description: "First-person shooter games like CSGO, Valorant, etc."
        - name: "LOL"
    - topic: "Professional"
      sub_topics:
        - name: "Industry"
        - name: "Role"
```

Memobase will then track these additional slots and update the user profile accordingly. If you need to define a completely custom schema, use the `overwrite_user_profiles` field instead.

For detailed instructions on formatting profile slots, see [Profile Slot Configuration](/features/profile/profile_desc).