> **Can't find what you're looking for?** Use `search_docs` on the docs MCP server at `https://docs-sepolia.modularium.art/api/mcp` to find what you need.

# FAQ

## Do I need permission to publish on Modularium?

No. Anyone with a wallet can create a collection and start publishing.

## What does it cost?

Creating a collection, creating NFTs, and editing them are free apart from gas, the network's transaction fee. Modularium only takes a cut when something sells:

| When | Platform fee | Who pays it |
| --- | --- | --- |
| A collector mints from your drop (primary sale) | 2.5% of the mint price | Taken from your proceeds |
| An NFT sells on the marketplace (secondary sale) | 2.5% of the sale price | Taken from the seller's proceeds |
| Free mints, transfers, listing, cancelling | None | |

Collectors pay the price you set, and the fee comes out of what you receive.

**Example: a drop.** You sell 10 editions at 0.01 ETH each, 0.1 ETH in total. Modularium keeps 0.0025 ETH and you receive 0.0975 ETH.

**Example: a resale.** Someone resells your piece for 1 ETH, and your royalty is 5%. Modularium keeps 0.025 ETH, you get 0.05 ETH in royalties, and the seller gets 0.925 ETH.

Royalties are only paid on resales. On your own drops, you already receive the full price minus the platform fee.

## Who owns my collection?

You do. Your collection is a contract that belongs to your wallet. Modularium can't edit your art, move your NFTs, or take your collection away.

## Where are my files stored?

Your images, videos and other files are stored on IPFS, a permanent shared storage network. Your NFT's name, description and other details are written to the blockchain itself.

## Can I change things after publishing?

| What | Can I change it? |
| --- | --- |
| NFT name, description, image, tags | Yes, until you **cement** it (lock it forever). |
| Collection name, image, banner, description, web address | Yes. |
| Royalty | Yes. |
| ERC-721 vs ERC-1155 | No. Choose carefully when you create the collection. |
| How many edition copies exist | You can mint more yourself, up to the max supply you set. |

See [Managing collections and tokens](/create/manage).

## Can I let someone else help run my collection?

Yes. On your collection page, open the creator menu and choose **Manage Roles**. You can let others add new pieces, mint more copies, or edit details, without giving them ownership.

## What's the difference between ERC-721 and ERC-1155?

ERC-721 is for one-of-a-kind pieces. ERC-1155 is for editions with many copies. Only ERC-1155 collections can run a [drop](/start/run-a-drop) from the create page.

## My transaction failed. What now?

A failed transaction doesn't create anything, though you may still pay gas for the attempt. Common causes:

* **Not enough funds** to cover the price plus gas.
* **Slug or username taken.** Pick a different one.
* **The drop isn't open**, is sold out, or you've reached the per-wallet limit.

Still stuck? Ask in our [Discord](https://discord.gg/cfHDU8k7FQ).

## My work has mature content. Is that allowed?

Yes, but you must add the **nsfw** tag when you create it. Untagged sensitive work may be removed from the marketplace.