One marketplace stops the title at 60 characters, the next allows 150. One wants five bullet points, another none. Paste the same text everywhere and it fits nowhere, so your team rewrites the same product for every channel. In Cernel every marketplace field has its own agent, written to that marketplace's rules from the same product data, so the facts match everywhere.
Your catalogueInsulated steel bottle, 500 ml
Moss
500 ml
Powder-coated stainless steel
Cold 24 h, hot 12 h
Leak-proof screw lid
Outdoor marketplace
Title
78 of 80 characters
Insulated steel bottle 500 ml, cold 24 h, hot 12 h, leak-proof lid, dark green
Bullet points
Three, short
Keeps drinks cold for 24 hours, hot for 12
Leak-proof screw lid
Double-walled stainless steel
Attributes
Its fields, from its value lists
Colour
Dark green
Capacity
0.5 l
Keeps cold
24 h
Description
Plain text, up to 1,000 characters
A 500 ml insulated bottle for day hikes and long rides. Double walls of stainless steel keep water cold for 24 hours.
Home marketplace
Title
31 of 60 characters
Insulated bottle, 500 ml, olive
Bullet points
None, highlights go in the description
None on this marketplace
Attributes
Its fields, from its value lists
Colour
Olive
Material
Steel
Capacity
500 ml
Description
HTML, short paragraphs
<p>A matte olive bottle that keeps water cold on your desk all day and tea hot through the afternoon.</p>
Cold water for the whole session and the ride home. Stainless steel, 500 ml, with a screw lid that does not leak.
General marketplace
Title
135 of 150 characters
Insulated Stainless Steel Water Bottle, 500 ml, Double-Walled, Keeps Drinks Cold 24 Hours and Hot 12 Hours, Leak-Proof Screw Lid, Green
Bullet points
Benefit first, in capitals
COLD FOR 24 HOURS: double walls keep water cold all day
HOT FOR 12 HOURS: coffee or tea stays hot
LEAK-PROOF: a screw lid that closes tight
Attributes
Its fields, from its value lists
Colour family
Green
Material
Metal
Capacity
500 ml
Description
Plain text, no HTML, up to 2,000 characters
This insulated water bottle holds 500 ml and keeps drinks cold for 24 hours or hot for 12, with a leak-proof screw lid.
Outdoor marketplace: title "Insulated steel bottle 500 ml, cold 24 h, hot 12 h, leak-proof lid, dark green" (78 of 80 characters). Bullet points: Keeps drinks cold for 24 hours, hot for 12; Leak-proof screw lid; Double-walled stainless steel. Colour: Dark green, Capacity: 0.5 l, Keeps cold: 24 h. Description, plain text, up to 1,000 characters. Home marketplace: title "Insulated bottle, 500 ml, olive" (31 of 60 characters). No bullet points. Colour: Olive, Material: Steel, Capacity: 500 ml. Description, html, short paragraphs. Sports marketplace: title "Insulated sports bottle 500 ml, stainless steel, cold 24 h, leak-proof screw lid, green" (87 of 100 characters). Bullet points: Cold for 24 hours, hot for 12; Leak-proof in a kit bag; 500 ml, double-walled steel. Colour: Green, Volume (ml): 500, Insulated: Yes. Description, plain text, up to 500 characters. General marketplace: title "Insulated Stainless Steel Water Bottle, 500 ml, Double-Walled, Keeps Drinks Cold 24 Hours and Hot 12 Hours, Leak-Proof Screw Lid, Green" (135 of 150 characters). Bullet points: COLD FOR 24 HOURS: double walls keep water cold all day; HOT FOR 12 HOURS: coffee or tea stays hot; LEAK-PROOF: a screw lid that closes tight. Colour family: Green, Material: Metal, Capacity: 500 ml. Description, plain text, no html, up to 2,000 characters. On the general marketplace a review step held a bullet point that claimed the bottle is dishwasher safe, which the product data does not say; your team edited it and approved. Each listing is then exported for its marketplace.
Example product, marketplaces, rules and texts. Cernel prepares the data; you upload it in the marketplace's seller tools, or your feed tool sends it.
A category tree per marketplace
Every marketplace sorts the shelf its own way.
Your shop files the bottle under Kitchen. An outdoor marketplace wants it under Camping, a general marketplace four levels down under Home & kitchen. In Cernel each marketplace's category tree sits next to yours. An agent places each product in the most specific category that fits, and that category brings the fields the marketplace asks for.
Your catalogueInsulated steel bottle, 500 ml
Your shop
KitchenDrinkwareWater bottles
Asks for Capacity, Material, Colour
Outdoor marketplace
CampingHydrationInsulated bottles
Asks for Capacity, Keeps cold, Keeps hot, Weight, Material, Colour
Fashion marketplace
SportsSports accessoriesBottles
Asks for Colour, from list, Sport, Capacity, Material
General marketplace
Home & kitchenKitchen & diningDrinkwareInsulated bottles
Asks for Colour family, Material, Capacity, Five bullet points
Example category trees and fields.
Rejected for one word
You call it Moss. One marketplace takes Dark green, the next only Green.
Every marketplace has its own list of colours, materials and sizes. Send a value that isn't on it and the listing is rejected, usually after you have uploaded it. Cernel sets up an agent for each marketplace field, with that marketplace's rules and value list, so every value it writes is one the marketplace accepts.
CernelSteel bottle, outdoor marketplace versionEvery value on its list
Keeps coldYour valueUp to 24 hoursOutdoor marketplace24 h
Every value is one the outdoor marketplace accepts. Your own values stay as they are.
Example values.
The marketplace's list goes in once
Each marketplace's colours, materials and sizes become the only values its field can take.
An agent per marketplace field
It reads your product, follows that marketplace's rules and picks the closest value on its list.
Your names stay yours
Moss stays Moss in your shop. Each marketplace gets the word it accepts, from the same product.
Before you upload
Find the gaps before the marketplace does.
An empty required field bounces the listing. An empty filter field lets it through, to a place where shoppers who filter never see it. Cernel measures completeness per marketplace and per market, agents fill only what is missing, and you export the products where every field the marketplace asks for has a value.
Cernel Home marketplace › CasserolesMarket: Germany
69%
Completeness for this marketplace
214 products, 5 tracked fields
Some tracked fields have no value:
Capacity58%
Hob type71%
Oven safe to34%
Colour, from list88%
Diameter96%
Measured against the fields this category asks for
Example category, products and figures.
Exports
Each marketplace gets the file it reads. Ready to upload.
Cernel prepares each marketplace's version, ready to upload in its seller tools or to send through the feed tool you already use. The ready products leave as a file in that marketplace's own column names and order, one language per file, or your feed tool picks up approved values over the API.
A file per marketplace
home-marketplace_casseroles_de.csv
sku
ean
article_name
capacity_l
hob_type
30418
5709876543210
Gusseisen-Bräter, 24 cm, Schwarz
4,2
Alle, inkl. Induktion
30421
5709876543227
Gusseisen-Bräter, 20 cm, Creme
2,4
Alle, inkl. Induktion
30433
5709876543234
Gusseisen-Schmortopf, 28 cm
6,7
Alle, inkl. Induktion
30440
5709876543241
Emaillierter Bräter, oval, 31 cm
5,5
Gas, Elektro
Columns named and ordered to the marketplace's template, in German, ready to upload in its seller tools.
Your feed tool picks up approved values over the API and sends them on.
Example files. The API response is shortened.
What changes
One catalogue. A ready version for every marketplace.
What goes out
A file per marketplace and language, in its own columns and order
The API, for your feed tool or your own code
Your own shop and PIM, from the same catalogue
What you control
Each marketplace's categories, fields and value lists, next to your own
One agent per marketplace field, with that marketplace's rules in its prompt
You choose which values go live automatically and which get a review step; review steps check every value and only ask a person when something fails or needs a decision
What you see
Completeness per marketplace and per market: which products still miss a field
Every AI-written value with its inputs, reasoning and prompt
Where each value came from: an agent, an import or a person
Cernel prepares each marketplace's version, ready to upload in the marketplace's seller tools or to send through the feed tool you already use. It leaves as a file with that marketplace's columns and order, one language per file, or your feed tool picks up approved values over the API.
Can we keep different values per marketplace?
Yes. Each marketplace gets its own fields next to yours, holding that marketplace's value list, and an agent set up with its rules picks from it. Your own naming stays as it is. Each marketplace's category tree sits next to yours too, so a product carries the fields its marketplace category asks for.
How do we handle several markets?
Every language you add is also a market. Content is written fresh or translated per language, each with its own instructions, and each country gets its own file.
How do we know a product is ready for a marketplace?
Track the fields a marketplace's category asks for. Completeness shows which products and fields are still empty, per marketplace and per market, agents fill only what is missing, and you export the products that are complete.
Does every value need a person to approve it?
No. You choose which values go live automatically and which get a review step; review steps check every value and only ask a person when something fails or needs a decision. A step can check a marketplace's title length or a claim your product data does not back, and a person sees the value with its inputs and reasoning.
Bring one product and the marketplaces you sell on.
In a demo we place your product in each marketplace's categories, write its title, bullet points and description to each one's rules, and show you which fields each marketplace still misses.