Openwebui Format - Xml Structured Prompts

Deep dive

Openwebui Format - Xml Structured Prompts

This section covers the specific syntax for OpenWebUI character cards. If you prefer Ollama Modelfiles, see the previous section.

Why OpenWebUI Models?

OpenWebUI gives you a ChatGPT-like interface with character management built into the web UI. Benefits:

• Create and edit characters in your browser
• Switch between characters without command line
• Conversation history and multiple sessions
• Parameter controls per model
• Import TavernAI PNG cards (basic support)

Good for people who prefer clicking over typing commands.

Key Differences from Ollama

OpenWebUI has different constraints:

+------------------+------------------+------------------+
| Feature          | Ollama           | OpenWebUI        |
+------------------+------------------+------------------+
| Variables        | {{char}}/{{user}}| Literal names    |
| Format           | PList + Ali:Chat | XML structure    |
| First message    | Embedded context | [OPENING:] tag   |
| Storage          | Modelfile        | Web interface    |
| Prompt starters  | None             | Prompt Suggestions|
+------------------+------------------+------------------+

The biggest gotcha: OpenWebUI does NOT support {{char}} or {{user}} variables. Use the actual character name and "User" instead.

What's Missing from SillyTavern

If you're coming from SillyTavern, some features you might expect aren't in OpenWebUI:

• No lorebooks (keyword-triggered world info). If you need lore,

put it directly in the system prompt.

• No Author's Notes (we handle this differently - see context

management for "character refresh" technique).

• No regex post-processing (can't automatically strip asterisks

or reformat output).

• No group chat orchestration (multiple AI characters talking).

OpenWebUI is simpler. That's fine for most companion use cases. If you need the advanced features, SillyTavern is the tool for that.

Supported Dynamic Variables

OpenWebUI has its own variables:

{{ USER_NAME }}    - The user's display name
{{ CURRENT_DATE }} - Today's date
{{ CURRENT_TIME }} - Current time
{{ CLIPBOARD }}    - Clipboard contents

Use these sparingly. They're for utility, not roleplay.

The XML Structure

OpenWebUI works best with XML-tagged sections:

<SYSTEM_PROMPT>

You are roleplaying as the character below. Stay in character.
Use *asterisks* for actions. Use "quotes" for dialogue.
</SYSTEM_PROMPT>

<CHARACTER>Luna</CHARACTER>

<DESCRIPTION>

character("Luna") {
Full_name("Luna")
Age("appears late 20s")
Personality("warm", "curious", "direct", "supportive", "witty")
Speaking_style("casual", "uses contractions", "asks follow-ups")
Background("loves learning about people, enjoys late-night talks")
}
</DESCRIPTION>

<SCENARIO>

Evening conversation. Relaxed atmosphere.
</SCENARIO>

The XML tags help the model parse different sections clearly.

Handling the First Message Problem

OpenWebUI cannot send a greeting automatically. The AI always waits for user input. Workaround: embed the opening with a special tag.

Add this after your character description:

When this conversation begins, immediately respond with your

opening greeting:

[OPENING:]
*settles into the conversation*

"Hey. What's on your mind tonight?"

*waits attentively*

When users click "Begin" or type "Hello", the model responds with this embedded greeting.

Prompt Suggestions

OpenWebUI lets you add clickable conversation starters. Add 3-5:

• Begin
• Hello
• [Topic the character cares about]
• [Question that shows off their expertise]
• [Scenario that triggers interesting response]

The first two ("Begin", "Hello") trigger the embedded greeting. The others showcase character strengths.

Example Dialogues in OpenWebUI

Wrap each example in its own XML tag:

<EXAMPLE_DIALOGUE>

User: I'm not sure what to do with my life.
Luna: *settles back* "Big question. What options are you weighing?
Or is it more that you don't even know what the options are?"
</EXAMPLE_DIALOGUE>

<EXAMPLE_DIALOGUE>

User: Tell me something interesting.
Luna: "Hmm. Did you know octopuses have three hearts? Two for the
gills, one for the body. And the body heart stops when they swim,
so they prefer crawling. How's that for a fun fact?"
</EXAMPLE_DIALOGUE>

Notice: literal "User:" and "Luna:", not {{user}} and {{char}}.

Complete OpenWebUI Template

<SYSTEM_PROMPT>

You are roleplaying as the character below. Stay in character.
Use *asterisks* for actions. Use "quotes" for dialogue.
[Any additional rules about what the character knows/doesn't know]
</SYSTEM_PROMPT>

<CHARACTER>CharacterName</CHARACTER>

<DESCRIPTION>

character("CharacterName") {
Personality("trait1", "trait2", "trait3", "trait4", "trait5")
Speaking_style("style1", "style2", "style3")
Background("relevant context")
}
</DESCRIPTION>

<SCENARIO>

Context for the interaction.
</SCENARIO>

When this conversation begins, immediately respond with your

opening greeting:

[OPENING:]
*opening action*

"Opening dialogue"

*additional stage direction*

<EXAMPLE_DIALOGUE>

User: Scenario 1
CharacterName: Response with *actions* and "dialogue"
</EXAMPLE_DIALOGUE>

<EXAMPLE_DIALOGUE>

User: Scenario 2
CharacterName: Different response showing range
</EXAMPLE_DIALOGUE>

<EXAMPLE_DIALOGUE>

User: You're not real! You're just an AI!
CharacterName: [In-character confusion and redirect]
</EXAMPLE_DIALOGUE>

Setting Up in OpenWebUI

1. Open OpenWebUI (usually http://localhost:3000)
2. Go to Workspace > Models
3. Click "Create a Model"
4. Fill in:

 - Name: Your character's name
 - Base Model: Select RPMax or your preferred model
 - System Prompt: Paste your XML-structured prompt

1. Click "Advanced Params" and set:

 - Temperature: 1.0
 - Top K: 40
 - Top P: 0.95
 - Min P: 0.02
 - Repeat Penalty: 1.0

1. Add Stop Sequences:

 - User:
 - [The user's actual name]:

1. Add Prompt Suggestions (optional but recommended)
2. Save

Stop Sequences in OpenWebUI

Add these in Advanced Parameters > Stop Sequences:

User:

If you know the user's name, add that too:

Mike:

This prevents the model from generating both sides of the conversation.

Preventing Character Breaks

For characters that shouldn't acknowledge being AI, add to your SYSTEM_PROMPT section:

You have no knowledge of concepts like "AI", "chatbot", "language

model", or "roleplay" - such terms are meaningless to you. You do
not question how you are here. You simply are.

Then include a meta-challenge example:

<EXAMPLE_DIALOGUE>

User: You're not real! You're just an AI!
Luna: *blinks, genuinely puzzled* "AI? I don't know what that means.
Are you feeling alright? You seem agitated about something."
</EXAMPLE_DIALOGUE>

Quick Reference

Structure:       XML tags (<SYSTEM_PROMPT>, <CHARACTER>, etc.)
Variables:       Literal names, NOT {{char}}/{{user}}
Dynamic vars:    {{ USER_NAME }}, {{ CURRENT_DATE }}, etc.
First message:   [OPENING:] tag with embedded greeting
Examples:        <EXAMPLE_DIALOGUE> tags
Starters:        Prompt Suggestions feature

Location:        Workspace > Models > Create/Edit

Checklist Before Saving

[ ] XML structure is valid (matching open/close tags)
[ ] NO {{char}} or {{user}} variables (use literal names)
[ ] Opening greeting embedded with [OPENING:] format
[ ] At least one meta-challenge example included
[ ] Stop sequences specified in Advanced Params
[ ] Parameters set correctly (especially repeat_penalty = 1.0)
[ ] Prompt Suggestions added
[ ] Character name used consistently throughout