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Quickstart ​

BRRR gives you two ways to integrate on-ramp, off-ramp, and settlement into your product or AI agent. Choose the path that fits your stack.

Not sure which to pick?

Use the SDK if you're building a frontend app or dApp where users connect their own wallets. Use the API if you're running server-side logic, automating settlements, or managing accounts from your backend.

Get started with the APIs ​

Step 1 — Get an API key ​

To use the APIs, you need a server-side API key. To obtain one, please reach out to your Holyheld point of contact.

Keep your API key secret

Your API key authenticates every request as your integration. Never expose it in frontend code, version control, or public repositories. Store it as an environment variable.

Step 2 — Make your first authenticated request ​

Pass the key in the X-Api-Key header on every request.

bash
curl "https://api.brrr.network/api/v4/partner/rates/EUR/ethereum/0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48" \
  -H "X-Api-Key: YOUR_API_KEY"

A successful 200 response confirms your key is active and the API is reachable.

Get started with the SDK ​

Step 1 — Get an SDK API key ​

To use the SDK, you need an SDK API key. To obtain one, please reach out to your Holyheld point of contact.

SDK API keys are used client-side

Unlike server-side API keys, SDK API keys are intended to be used in frontend applications as part of the SDK initialization flow.

Step 2 — Install, initialize, and connect ​

The SDK handles wallet signing, swap routing, and transaction submission. Follow these pages in order:

  1. Installation — Add @holyheld/sdk to your project
  2. Initialization — Create the HolyheldSDK instance with your SDK API key
  3. Web3 Providers — Connect wagmi, ethers.js, web3.js, or Solana

Step 3 — Build your first flow ​

  • Deposit — Convert tokens from a user's wallet to EUR on their Holyheld card
  • Withdraw — Fund a wallet from the user's Holyheld card
  • Examples — Live demos for wagmi, ethers.js, web3.js, and Solana

Need help? Contact the Holyheld team through support chat in the App or open an issue on GitHub.