> For the complete documentation index, see [llms.txt](https://docs.usewinter.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.usewinter.com/marketplace-integrations/implementation-strategy/build-and-submit-a-transaction.md).

# Build and submit a transaction

This type of integration is where we call your API (e.g. \`marketplace.com/buildTx\`), we sign the transaction, and then we pass it to your API (e.g. \`marketplace.com/submitTx\`) and you submit it to your RPC!

These types of integrations are for **high volume** marketplaces where having consistency is important! With this type of integration, you can control the flow and show all pending transactions (e.g. only allow 1 buy order on each NFT to prevent gas wars)

🚧 Coming soon - a self serve dashboard for you to integrate on your own!

These are the chains we currently support for this type of integration:

* ETH
* MATIC
* SOL
* ADA
* XTZ
* AVAX
* BNB

At a high level, your API should take in a few things (passed in this format):

* `tokenId`
* `contractAddress`
* `quantity (optional)`

We then expect a complete **unsigned** transaction back, which we will then sign!

We then expect a second api to take in a **signed** transaction and return back:

* `isSubmitSuccessful`
* `txHash`

To get started, email us at `marketplaces@usewinter.com!`