evm-nft - Dokrypt

Overview

A complete NFT project with an ERC-721 collection, decentralized marketplace, and EIP-2981 royalty standard. Includes IPFS for metadata storage and Blockscout for browsing.


Difficulty	Intermediate
Category	NFT
Chains	Ethereum
Services	IPFS (port 5001), Blockscout (port 4000)
License	Apache-2.0

Quick Start

dokrypt init my-nft --template evm-nft
cd my-nft
dokrypt up
# ethereum    Ready  http://localhost:8545
# ipfs        Ready  http://localhost:5001
# blockscout  Ready  http://localhost:4000

Generated Files

my-nft

dokrypt.yaml

foundry.toml

README.md

contracts

NFTCollection.sol

Marketplace.sol

Royalty.sol

test

NFTCollection.t.sol

Marketplace.t.sol

Royalty.t.sol

scripts

deploy-nft.js

upload-metadata.js

Configuration

version: "1"
name: my-nft

chains:
  ethereum:
    engine: anvil
    chain_id: 31337
    block_time: "2s"

services:
  ipfs:
    type: ipfs
    port: 5001
    gateway_port: 8080
  explorer:
    type: blockscout
    chain: ethereum
    port: 4000

Contracts

NFTCollection.sol (ERC-721)

Full standalone ERC-721 implementation with minting and metadata. Constructor:

constructor(
    string memory name,
    string memory symbol,
    string memory baseURI,
    uint256 maxSupply,
    uint256 mintPrice
)

Functions:

Function	Access	Description
`mint()`	Public (payable)	Mint an NFT at the configured price
`safeTransferFrom(from, to, tokenId)`	Public	Transfer with receiver check
`transferFrom(from, to, tokenId)`	Public	Transfer without receiver check
`approve(to, tokenId)`	Public	Approve transfer
`setApprovalForAll(operator, approved)`	Public	Approve operator for all tokens
`setBaseURI(newBaseURI)`	Owner	Update metadata base URI
`tokenURI(tokenId)`	View	Returns `{baseURI}{tokenId}`
`balanceOf(owner)`	View	Token count for address
`ownerOf(tokenId)`	View	Owner of specific token

Minting Logic:

Payment must equal mintPrice
Cannot exceed maxSupply
Token IDs are sequential starting from 1

Interfaces implemented: IERC721, IERC721Metadata, IERC721Receiver

Marketplace.sol

Decentralized NFT marketplace with listings, offers, and platform fees. Fee: 2.5% platform fee (250 basis points) on all sales. Functions:

Function	Access	Description
`listItem(nft, tokenId, price)`	Public	List an NFT for sale
`buyItem(nft, tokenId)`	Public (payable)	Buy a listed NFT
`cancelListing(nft, tokenId)`	Seller	Cancel a listing
`makeOffer(nft, tokenId)`	Public (payable)	Make an offer (ETH attached)
`acceptOffer(nft, tokenId, offerer)`	Seller	Accept a specific offer
`withdrawOffer(nft, tokenId)`	Offerer	Withdraw your offer
`withdrawPlatformFees()`	Owner	Withdraw collected fees

Events: ItemListed, ItemSold, ItemCanceled, OfferMade, OfferAccepted Listing struct:

struct Listing {
    address seller;
    uint256 price;
    bool active;
}

Royalty.sol (EIP-2981)

EIP-2981 royalty standard implementation for NFT secondary sales. Functions:

Function	Access	Description
`setDefaultRoyalty(receiver, basisPoints)`	Owner	Set default royalty for all tokens
`setTokenRoyalty(tokenId, receiver, basisPoints)`	Owner	Override royalty for specific token
`royaltyInfo(tokenId, salePrice)`	View	Returns (receiver, royaltyAmount)
`supportsInterface(interfaceId)`	View	ERC-165 interface detection

Constraints:

Maximum royalty: 10% (1000 basis points)
Per-token royalties override the default
Calculation: royaltyAmount = salePrice * basisPoints / 10000

IPFS Metadata

Upload Metadata

npx hardhat run scripts/upload-metadata.js --network localhost

Metadata Format

{
  "name": "My NFT #1",
  "description": "A unique digital collectible",
  "image": "ipfs://IMAGE_CID",
  "attributes": [
    { "trait_type": "Background", "value": "Blue" },
    { "trait_type": "Rarity", "value": "Rare" }
  ]
}

Upload images and metadata JSON to IPFS, then set the base URI:

nft.setBaseURI("ipfs://YOUR_METADATA_CID/");
// tokenURI(1) → "ipfs://YOUR_METADATA_CID/1"

Deployment

npx hardhat run scripts/deploy-nft.js --network localhost

Deploys NFTCollection and Marketplace. Parameters:

Collection name, symbol
Base URI (IPFS CID)
Max supply
Mint price (in wei)

​Overview

​Quick Start

​Generated Files

​Configuration

​Contracts

​NFTCollection.sol (ERC-721)

​Marketplace.sol

​Royalty.sol (EIP-2981)

​IPFS Metadata

​Upload Metadata

​Metadata Format

​Deployment

Overview

Quick Start

Generated Files

Configuration

Contracts

NFTCollection.sol (ERC-721)

Marketplace.sol

Royalty.sol (EIP-2981)

IPFS Metadata

Upload Metadata

Metadata Format

Deployment