If the AI keeps answering a field differently than you'd like — your sizing conventions, your tone, a measurement your brand defines its own way — write it down once as a custom instruction on that field. Every future Prompt that touches the field follows your guidance automatically.
Add instructions to a field
- In the sidebar, open your marketplace and click Fields.
- Search for the field and open it, then click the Edit button.
- In the Mapping card, find the Extra AI Instructions box.
- Write your guidance in plain English.
- Click Save.
Two shortcuts take you to the same place: on a listing's Fields tab, open the ... menu on any field's row and choose Manage Field; or, from a Field Prompt's field detail page, choose Manage Field from the ... menu.
What to write
Short, specific, factual statements work best:
- "Sleeve length is measured from the center back of the neck, not the shoulder seam."
- "Our fits run small — when choosing a fit description, size up."
- "Never mention other brand names in descriptions."
The field edit page also sets the Mapping method — by default the AI decides how to fill the field from all your product data, but you can limit it to specific source attributes, pin a fixed value, or turn the field off. Instructions apply to the AI-driven methods; a fixed value or a field that's off has nothing for the AI to read.
Formatting your instructions
Instruction boxes support Markdown, and you can write them either of two ways. A small toggle in the box's top-right corner switches between them at any time:
- Rich text — a toolbar for bold, italic, headings, bullet and numbered lists, inline code, code blocks, quotes, links and tables. Formatting is applied as you type.
- Markdown — the raw markdown source, if you'd rather type
**bold**and-yourself.
Both write the same thing, so switching never changes what you've written. Placeholders like {{ product_type }} and names with underscores are preserved exactly as typed in either view.
Formatting is optional — plain sentences work well. Headings and lists mostly help when a field needs several distinct rules.
Tables
Click the table button in the toolbar to insert a 3×3 table with a header row. Put the cursor in any cell and a second row of controls appears underneath the toolbar for adding and removing rows and columns, toggling the header row, or deleting the table.
Tables are saved as standard markdown pipe tables, so they stay readable and editable in Markdown view too. If you need a literal | inside a cell, type it normally — it's escaped for you when saved.
Tables are useful for anything with repeating structure, like a size chart or a per-category rule:
| Category | Rule |
|---|---|
| Dresses | Measure length from the shoulder seam |
| Knitwear | Always mention the fibre blend |
To choose which view instruction boxes open in by default, set Editor on your Preferences page.
Per-category instructions
The same marketplace field can need different guidance for different product categories. When you edit a field from a specific category (for example, via Manage Field on a categorized listing), instructions you add there are appended to the field's universal instructions — the universal guidance still applies, plus your category-specific note on top.
Ask the AI to save an instruction for you
You can also teach the AI from a listing's or variant's AI Chats tab. Tell it plainly that you want something applied going forward — "From now on, measure sleeve length from the center back of the neck" or "Remember: any SKU containing ABC-123 belongs in the Outdoor Lighting category" — and it adds the rule to that field's custom instructions for the whole marketplace, below anything you've already written there. Open the field's edit page afterwards and you'll see it in the Extra AI Instructions box, ready to tweak.
A few things to know:
- The AI only saves an instruction when you ask it to remember something. Asking it to fix a value on the listing in front of you changes that value, not the field's instructions.
- Saved rules are general by design. The AI won't write a rule about one specific listing or product, because every future fill of the field across the marketplace reads it — rules about SKU patterns, product types, or how your brand measures things are the right fit.
- Rules saved this way apply to the field in every category of that marketplace. For a category-only rule, use the per-category instructions described above.
- Saving a rule doesn't change existing values — re-run the field to apply it (see "When instructions take effect" below).
Store-wide instructions
For guidance that should shape everything the AI writes, open the store menu at the bottom of the sidebar, choose Profile & Preferences, and go to the Listing Settings tab. The Universal Custom Instructions box applies across every marketplace on your store. Your Store Profile — especially "What do you sell?" — also feeds the AI context about your catalog, so it's worth filling in well.
When instructions take effect
Instructions apply to every Prompt that runs after you save them. Existing values don't change on their own — re-run the field (choose Update with AI on the field's row, or run Fill in With AI with Skip filled values unchecked) to apply your new guidance. To confirm they were used, open the prompt's field detail: the "Instructions Followed" section shows exactly what the AI was told.