# Phase 2, Step 4: (Optional) Automate NFT Minting (If Pursuing NFTs) This document outlines the process for automating the minting of "On This Day" collectibles as Non-Fungible Tokens (NFTs). This step is applicable only if the project has chosen the NFT path (decision from P1-S4) and aims for a high degree of automation in daily operations. ## Key Objectives: * Develop scripts to automatically mint the daily generated card images as NFTs on the chosen blockchain. * Automate the preparation and uploading of NFT metadata. * Manage wallet interactions, gas fees, and transaction confirmations programmatically. * Ensure robust error handling for the minting process. ## Prerequisites: * **Completed P1-S4:** Decision made to use NFTs, blockchain selected (e.g., Polygon, Ethereum), and minting strategy considered (marketplace tools vs. custom contract). * **Completed P2-S3:** Automated card design population and export, resulting in final card image files (e.g., `YYYY-MM-DD-Card-Final.png`). * **Familiarity with Blockchain Concepts:** Understanding of smart contracts, gas, wallets, and the chosen blockchain's specifics. * **Development Environment:** Setup for interacting with the chosen blockchain (e.g., Node.js with Web3.js/Ethers.js for Ethereum/Polygon, or relevant SDKs for other chains). * **Funded Wallet:** A wallet with sufficient native currency for gas fees on the chosen blockchain. ## Actionable Steps: 1. **Finalize NFT Minting Strategy:** * **Custom Smart Contract:** * **Pros:** Maximum control over NFT properties, minting logic, and potential future features. Can optimize for batch minting. * **Cons:** Requires Solidity (for EVM chains) development skills, thorough testing, and auditing (which can be expensive). Higher upfront effort. * **Marketplace/Platform APIs (if available):** * Some platforms (e.g., Pinata for IPFS, third-party minting services like NFTPort, Alchemy Minting API) offer APIs to programmatically mint NFTs or manage metadata. * **Pros:** Simplifies interaction with the blockchain, may handle some complexities. * **Cons:** Reliance on a third-party service, potential fees, less control than a custom contract. * **Marketplace Minting Tools (Semi-Automated):** If full API automation isn't available or too complex initially, consider scripting browser automation (e.g., with Puppeteer/Playwright) to interact with a marketplace's manual minting interface. This is fragile and less recommended for robust automation. 2. **Prepare NFT Assets & Metadata:*** **Image Storage (IPFS):** NFT metadata typically points to the image URL. Storing images on IPFS (InterPlanetary File System) is a decentralized standard. * Script the uploading of the final card image (from P2-S3) to an IPFS pinning service (e.g., Pinata, Infura IPFS, Filebase). * Obtain the IPFS content identifier (CID) for each image. * **Metadata JSON File:** Create a JSON file for each NFT conforming to its standard (e.g., ERC721/ERC1155 metadata schema). This includes: * `name`: Name of the NFT. * `description`: Description. * `image`: URL to the image on IPFS (e.g., `ipfs://CID/image.png`). * `attributes`: Array of traits (e.g., date, event type, rarity elements). * Script the generation of these JSON metadata files and upload them to IPFS as well. The URL of this metadata JSON on IPFS is what the smart contract will point to. 3. **Develop Minting Scripts (interacting with Smart Contract or API):** * **If Custom Contract:** * Use libraries like Web3.js or Ethers.js (for EVM chains) to load your deployed smart contract. * Write functions to call the contract's `mint` function (or a batch mint function if implemented), passing the IPFS URL of the metadata JSON. * **If Using Minting Service API:** * Use an HTTP client in your script to interact with the service's API endpoints for minting. * Provide the image, metadata, and recipient wallet address as required by the API. * **Wallet Management:** Securely manage the private key of the minting wallet (e.g., using environment variables or a secure vault service – NEVER hardcode private keys). * **Gas Fee Management:** Estimate and handle gas fees. For EVM chains, you can specify gas price and limit. Monitor gas prices to avoid overpaying or failed transactions.4. **Automate Transaction Monitoring & Confirmation:** * After sending a minting transaction, programmatically wait for it to be confirmed on the blockchain. * Retrieve the transaction hash and, upon confirmation, the token ID of the newly minted NFT. * Log all minting activities, transaction hashes, token IDs, and any errors. 5. **Error Handling & Retries:** * **Network Issues:** Implement retries for temporary network problems. * **Gas Price Spikes/Out-of-Gas Errors:** Handle transactions failing due to gas issues. Potentially allow for resubmission with higher gas. * **Smart Contract Errors:** Catch and log errors returned by the smart contract. * **IPFS Upload Failures:** Handle issues with uploading assets to IPFS. * **Alerting:** Set up alerts for critical failures in the minting process. 6. **Batching Considerations (for 1440 NFTs/day):** * Minting a large number of NFTs one by one can be slow and costly (in gas).* If using a custom smart contract, implement a batch minting function (e.g., `mintBatch(address to, uint250[] tokenURIs)`). * If using a service, check if it supports batch operations. * This significantly improves efficiency and reduces costs. 7. **Testing on a Testnet:** * **Crucial Step:** Before deploying to mainnet and spending real gas, thoroughly test the entire automated minting pipeline on a testnet (e.g., Sepolia for Ethereum, Mumbai for Polygon). * Use testnet faucets to get free test cryptocurrency. * Verify images and metadata are correctly uploaded to IPFS. * Verify NFTs are minted correctly with the right metadata and ownership. * Test all error handling and retry logic. ## Deliverables for this Step: * Scripts for automating IPFS uploads of images and metadata. * Scripts for automatically minting NFTs (interacting with a smart contract or service API). * Documented setup for the minting wallet and security considerations. * Robust error handling and logging for the minting process. * Confirmation of successful batch testing on a testnet. Automating NFT minting is a complex step involving blockchain interaction and requires careful development and testing, especially if handling valuable assets or a large volume.