How to Write an AI Character That Works in Any App
By myaicompanion Editorial · Updated 2026-10-23
A good AI character definition is short, specific and written so any app can use it.
I rebuilt every character on this site with the same card, and it is the one habit that keeps characters from forgetting who they are.
If you are moving your bots off Character.AI, this is the part that actually travels. Chats stay behind, but a well-written character card works in almost any companion app. Here is the format I use for every character on this site, with a template you can copy.
Quick answer. Write six fields: name, one-line identity, personality, scenario, greeting and two short example exchanges. Keep the whole card under about 400 words. Describe behaviour you can see ("teases you, then apologises too fast") rather than labels ("nice, funny"). Copy the template below, fill it in, and paste it into your new app's character or persona field.
Why most characters fall apart
Most characters break for one of three reasons.
The definition is a list of adjectives, so the model has nothing concrete to act on.
The backstory is so long that the important traits get lost.
There are no examples of how the character talks, so the model falls back to its default voice.
A portable card fixes all three.
The 6 fields of a portable character card
| Field | What to write | Length |
|---|---|---|
| Name | The character's name, plus a nickname if they use one | 1 line |
| Identity | Who they are in one sentence: role, age (always adult), setting | 1 sentence |
| Personality | 4–6 behaviours you could see on camera | 3–6 lines |
| Scenario | Where the story starts and who the user is to them | 2–4 lines |
| Greeting | The first message, in the character's voice | 2–5 sentences |
| Example dialogue | Two short exchanges that show the voice | 4–8 lines |
The template
Copy this, replace the brackets, and delete anything you don't need.
NAME: [Name] ("[nickname]")
IDENTITY: [Name] is a [age, adult] [role] in [setting].
PERSONALITY:
- [Behaviour 1, e.g. "answers questions with a question when nervous"]
- [Behaviour 2]
- [Behaviour 3]
- [Behaviour 4]
- Speaks in [short / formal / playful] sentences; uses [a verbal habit].
SCENARIO: [Where the first scene happens]. {{user}} is [the user's role] and [what just happened].
GREETING:
[2–5 sentences in the character's voice that set the scene and invite a reply.]
EXAMPLE DIALOGUE:
{{user}}: [a typical message]
[Name]: [a reply that shows the voice]
{{user}}: [a second message]
[Name]: [a second reply]
BOUNDARIES: [Name] is an adult. Stay in character. Keep the story fictional.
{{user}} is a placeholder many apps replace with your name.
If your app does not support it, write "you" instead.
If your new app imports character files, two references are worth a look: the SillyTavern character design guide explains how each field shapes replies, and the open Character Card V2 specification documents the file format many apps share.
Write behaviours, not adjectives
"Kind, funny, mysterious" tells the model almost nothing.
Behaviours tell it what to do.
| Instead of | Write |
|---|---|
| Shy | Looks for an excuse to leave when the conversation gets personal, then comes back |
| Funny | Makes dry jokes at their own expense, never at the user's |
| Protective | Steps between the user and trouble before asking what happened |
| Mysterious | Answers personal questions with a story about someone else |
Let the greeting do the heavy lifting
The greeting is the strongest signal in most apps.
It sets the tone, the tense, the length of replies and the scene.
If you want short, punchy replies, write a short, punchy greeting.
If you want a slow-burn story, open in the middle of a scene and end on something the user can react to.
Use example dialogue sparingly
Two short exchanges are usually enough to lock in a voice.
More than that and the model starts copying lines word for word.
Make the examples typical moments, not the most dramatic ones.
How to move a Character.AI bot to a new app
- Open the character on Character.AI while the service is still running.
- Copy its name, description, definition, greeting and any example dialogue into a document.
- Rewrite it into the six fields above, cutting anything vague.
- In the new app, create a character and paste each field into the matching box. If there is only one big box, paste the whole card.
- Start a chat and test three things: the voice, the scenario and whether it remembers a detail you mention early.
Character.AI is in a court-supervised sale, so do step 1 soon.
My bankruptcy guide has the timeline.
Common mistakes
- A wall of backstory. Keep only what changes how the character acts today.
- Contradictions. "Cold and distant" plus a greeting full of hearts confuses the model.
- Writing the user's actions. Let the user decide what they do and feel.
- Ages that are unclear. Every character on this site is an adult, and your cards should say so.
Ready-made characters
If you want a starting point, my character archetypes are complete cards built with this exact template: copy one, change the details and make it yours.
Frequently asked questions
How long should an AI character definition be?
Aim for roughly 200 to 400 words.
Short, concrete details work better than long backstories.
Can I copy my Character.AI bot to another app?
You can copy its definition and paste it into the new app's character fields.
It will sound a little different, because every app uses a different model.
Why does my AI character forget its personality?
Usually the definition is vague or too long, or the chat has drifted far from it.
Concrete behaviours, short examples and a clear greeting keep the model anchored.
Should I write the character in first or third person?
Third person works in almost every app.
Keep the greeting and example dialogue in the character's own voice.
The bottom line
A portable AI character definition is six short fields, written as behaviours, with a greeting that sets the tone.
Write it once and you can take your character to any app.
How I write this. This guide describes the card format I use for every character on myaicompanion. App fields differ, so check your app's help page for exact field names. Last updated on October 23, 2026. myaicompanion Editorial
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