Crosslist one listing across marketplaces from Claude.
Connect once and Claude becomes a crosslisting tool: describe the product once, and ask for it rewritten for any of the six marketplaces Optimlister covers - each version follows that marketplace's own title length, tag or bullet rules and its own keyword demand, because a listing copy-pasted across marketplaces under-performs the one written for it.
- Get your key. Every Optimlister plan has an API key, Free included - it lives in your account.
- Add the connector. In Claude: Settings, then Connectors, then Add custom connector. Name it Optimlister, URL https://optimlister.ai/api/mcp, and send your key as Authorization: Bearer opk_...
- Ask. That is the whole setup. Your first successful connect adds 10 credits to your balance.
Key lives at your account · full setup details on the Connect your AI page.
Each marketplace has its own title length, tag rules and buyer search behavior - the same product gets a genuinely different listing per marketplace, built on that marketplace's own keyword demand.
Amazon, Etsy, eBay, Walmart, Shopify and TikTok Shop are all reachable from the same chat, so a seller crosslisting a catalog does not switch tools per marketplace.
Character limits, required fields and prohibited claims are checked against each marketplace's own rules before you paste anything in.
I sell this product: <describe it>. Write me the Amazon version first, then the Etsy version, then the eBay version - each one built to that marketplace's own rules and keywords, not the same text copy-pasted.
Get your keyHow connecting works
Questions
Is crosslisting not just copying the same listing everywhere?
That is what most crosslisting tools do, and it under-performs - Amazon's 75-character Item name plus 125-character Item Highlights structure reads wrong on Etsy's buyer-friendly title and tag system. Optimlister rewrites the listing per marketplace instead of copying it.
Does this cost extra on top of Claude?
The MCP server and API key come with every Optimlister plan, including Free. Tool calls price exactly like the site: listings use your monthly listings, photos and video use credits at the same rates, and free tools stay free.
Is this official MCP?
Yes - Optimlister runs a standard MCP (Model Context Protocol) server over HTTP, the same open standard Claude uses for all its connectors. One URL, one key, no extension to install.
Can it work from a listing I already have somewhere else?
Yes - paste the existing listing's text and ask for it rewritten for a different marketplace; it works from what you give it rather than starting from nothing.
See it work
Three steps, and what each one actually produces - words, pictures and video.

- Deep juice groove catches runoff from meat and fruit
- Reversible: groove side for carving, flat side for bread
- Knife-friendly bamboo, no dulling


- Material: Bamboo
- Size: 17 in x 11 in
- Features: Juice Groove, Reversible
- Condition: New

- Juice groove keeps counters dry
- Reversible two-sided board
- Hand wash, oil monthly


- Material: Bamboo
- Size: 17 x 11 in
- Hook line for the video caption