Building on Polygon Crest: Step-by-Step Integration Tips

1. Prepare your environment

Tools: Node.js (16+), npm/yarn, Git
SDKs: Install Polygon Crest SDK (assume package name @polygon/crest) and ethers.js
```
Code
npm install @polygon/crest ethers 
```
Keys: Create or obtain a wallet private key and an API key from Polygon Crest (store in .env).

2. Initialize project and config

Project scaffold:

Code
mkdir crest-integration && cd crest-integration npm init -y

Environment file (.env):
- CREST_API_KEY=your_api_key
- PRIVATE_KEY=your_wallet_private_key
- RPC_URL=https://polygon-rpc.example (use Crest RPC if provided)

3. Connect wallet and provider

Use ethers to connect:

js
import { ethers } from “ethers”;
import Crest from ”@polygon/crest”;

const provider = new ethers.providers.JsonRpcProvider(process.env.RPC_URL);
const wallet = new ethers.Wallet(process.env.PRIVATE_KEY, provider);
const crest = new Crest({ apiKey: process.env.CREST_APIKEY, provider, wallet });

4. Deploy or connect to contracts

Option A — Use Crest managed contracts: Call Crest SDK methods to create collections or use their factory functions.
js
const collection = await crest.collections.create({ name: “My Collection”, symbol: “MCLT”, // additional metadata });

Option B — Deploy your own contracts: Compile and deploy an ERC-⁄₁₁₅₅ contract, then register its address with Crest if needed.

5. Upload assets and metadata

Storage: Use Crest’s recommended storage (IPFS/Arweave) via the SDK.
js
const asset = await crest.storage.uploadFile(”./art.png”); const metadata = { name: “Art #1”, description: ”…”, image: asset.url }; const metaCid = await crest.storage.uploadJSON(metadata);

Ensure metadata follows ERC standards (name, description, image, attributes).

6. Minting flow

Server-side mint endpoint: Create an authenticated endpoint to sign mint transactions or call Crest mint API.

Client-side interaction: Use Crest SDK to initiate mint and wait for transaction confirmation.
js
const tx = await crest.mint({ collectionId: collection.id, to: recipientAddress, metadataUri: metaCid, }); await tx.wait();

7. Integrate marketplace and royalties

Configure default royalties when creating collections or set on-chain via your contract.

Register listings with Crest marketplace APIs to enable secondary sales.

8. Handle events and indexing

Subscribe to contract events (Transfer, Mint) via provider or use Crest webhooks/indexer for reliable updates.
js
provider.on(“transfer”, (from, to, tokenId) => { /* update DB */ });

9. Testing and staging

Use Polygon testnet or Crest sandbox. Run unit tests, integration tests, and user acceptance tests. Automate with CI (GitHub Actions).

10. Security and best practices

Use secure key management (vaults, KMS).

Validate and sanitize metadata.

Rate-limit API calls and handle retries/backoff.

Monitor gas usage and optimize minting (batching, lazy mint).

Quick checklist before launch

API keys and RPC configured

Contracts audited or reviewed

Metadata storage immutable and accessible

Royalties and marketplace settings verified

Webhooks/indexer integration tested

If you want, I can generate example code for a specific part (minting, metadata upload, or webhook handling).

Building on Polygon Crest: Step-by-Step Integration Tips