Getgems NFT Contracts

The Getgems Minting API allows you to create NFTs via REST API calls without direct blockchain interaction. To use the API, you must top up a special wallet provided by Getgems to cover gas fees. The API is available for both mainnet and testnet.

Key Constraints:

• Rate Limiting: Maximum of 400 requests per 5 minutes per IP. Exceeding this results in an HTML error page.
• Cost: Minting a single NFT costs approximately 0.023 TON (gas fees).

API Documentation:

• UI: https://api.getgems.io/public-api/docs (Testnet: https://api.testnet.getgems.io/public-api/docs)
• OpenAPI Schema: https://api.getgems.io/public-api/docs.json

# Example of a POST request to mint an NFT (Testnet)
curl -X 'POST' \
  'https://api.testnet.getgems.io/public-api/minting/{{collectionAddress}}' \
  -H 'accept: application/json' \
  -H 'Authorization: {{authorization}}' \
  -H 'Content-Type: application/json' \
  -d '{ "requestId": "1689451433227", "ownerAddress": "UQB5HQfjevz9su4ZQGcDT_4IB0IUGh5PM2vAXPU2e4O6_YBm", "name": "Spotty", "description": "This is my cool nft collection", "image": "https://s.getgems.io/nft/b/c/62bd932a7b5f87901f3d8d19/image.png", "attributes": [{ "trait_type": "Background", "value": "Red" }] }'

Compressed NFTs (cNFTs) are a specialized format designed to significantly reduce minting costs for large-scale collections.

Use cNFTs if:

• Your collection contains more than 50,000 NFTs.

Key Considerations for cNFTs:

• Owner Addresses: You must know the addresses of all NFT owners in advance (though collections can be minted in parts if not).
• Fixed Capacity: You must specify the maximum number of NFTs in the collection at creation time. This number cannot be changed later.
• Cost: Minting each part costs 1 TON. The number of NFTs per part is unlimited.
• Conversion: cNFT owners must pay approximately 0.085 TON to convert a cNFT into a regular NFT for trading.
• Getgems Visibility: By default, only the first 1,000 cNFTs are shown on Getgems. To display the full collection, you must contact support via https://t.me/nfton_bot.

The nft-fixprice-sale-v4 contract facilitates the sale of NFTs for a fixed price in either TON or Jettons.

Workflow:

1. Deployment: The seller deploys the sale contract and transfers the NFT to it.
2. Purchase: The buyer sends the required amount of TON/Jettons plus an additional amount (approximately 0.1 to 0.26 TON) to cover gas fees.
3. Execution: The contract transfers the NFT to the buyer and the payment to the seller. The sale is then marked as complete.
4. Cancellation: The seller can cancel the sale at any time before a purchase occurs.

Critical Requirements:

• Bounce Flag: All messages sent to this contract must be sent with the bounce flag enabled. The contract will throw errors otherwise.
• Gas Coverage: Ensure the transaction includes enough TON to cover the ownership change (minimum ~0.1 TON). If the exact amount is unknown, it is recommended to send 1 TON; any unused funds will be returned to the sender.

The Auction contract is designed for scenarios with high buyer competition for a single NFT. A seller puts an NFT up for auction, and buyers place bids. The highest bidder wins.

Key Mechanics:

• Bidding Rules: Each subsequent bid must be greater than the previous one by a specified percentage (min_step) and must be at least 0.1 TON higher.
• Price Limits: The seller can set a min_bid (minimum starting price) and a max_bid (the price at which the NFT can be immediately bought out).
• Duration: Recommended duration is 3 days, with a maximum limit of 19 days.
• Cancellation: The seller can cancel the auction only if no bids have been placed. If at least one bid exists, the auction must run until completion or until the max_bid is reached.
• Anti-Sniping Protection: If a bid is placed within a configurable window (up to 1 day) before the auction ends, the auction duration is extended by a set amount of time (step_time, e.g., 5 minutes).
• Error Handling: All messages sent to this contract must be sent with the bounce flag, as the contract throws errors on invalid operations.

Compressed NFTs (cNFTs) are a specialized format designed to significantly reduce minting costs for large collections.

When to use cNFTs:

• Use cNFTs if your collection contains more than 50,000 NFTs.

Key Characteristics:

• Owner Addresses: You must know the owner addresses for every NFT in advance. If you cannot determine all addresses at once, you can mint the collection in parts (each part costs ~1 TON and has no limit on the number of NFTs).
• Fixed Capacity: You must specify the maximum number of NFTs in the collection during creation. This number cannot be changed later, so it is recommended to include a buffer (e.g., set 100,000 for a 70,000 NFT collection).
• Conversion Cost: To trade a cNFT like a standard NFT, owners must pay approximately 0.085 TON to convert it.
• Getgems Visibility: By default, only the first 1,000 cNFTs are shown on Getgems. To ensure your full collection is visible, contact support via https://t.me/nfton_bot.

The Offer contract facilitates a process where a buyer makes a purchase proposal to an NFT owner.

Workflow:

1. Initiation: The buyer creates the Offer contract and transfers the desired purchase amount to it.
2. Seller Action: The NFT owner can accept, reject, or ignore the offer.
3. Completion: If the seller accepts, they transfer their NFT to the Offer contract. The contract then automatically swaps the assets: it sends the NFT to the offer_owner_address and sends the TON funds to the original NFT owner.
4. Expiration: Offers have a validity period defined by a timestamp. After this time, the offer is considered invalid and can be canceled via an external message.

Cancellation: If a seller rejects an offer, the marketplace must manually cancel it. To do this, the marketplace sends a message with op-code 3. The marketplace is permitted to withdraw up to 0.5 TON from the contract to cover cancellation costs.

Implementation Note: When performing the swap, the marketplace should send sufficient TON to cover gas for the NFT exchange. A recommended forward_amount is 0.5 TON, though this may vary depending on the specific NFT.