Getting started on Avalanche Fuji (Day 0)

This page gets you ready to build Privacy on Avalanche on Fuji C-Chain before you touch PoD Solidity or the TypeScript SDK.

You will:

1. Add Avalanche Fuji C-Chain to your wallet

2. Fund the wallet with test AVAX

3. Configure Hardhat or Foundry for Fuji

4. Confirm a transaction on SnowScan

5. Jump into PoD with the right packages and next tutorial

Scope: This is the C-Chain (EVM) testnet — chain ID 43113. It is not an Avalanche L1/subnet setup guide.

1. Network parameters (copy into your wallet)

Field	Value
Network name	Avalanche Fuji C-Chain
RPC URL	https://api.avax-test.network/ext/bc/C/rpc
Chain ID	43113
Currency symbol	AVAX
Block explorer	https://testnet.snowscan.xyz

Full PoD contract tables: Avalanche Fuji.

Core

Core usually includes Fuji. Switch the network to Fuji / Avalanche Fuji C-Chain, or add the RPC above if you manage networks manually.

MetaMask (or any EIP-3085 wallet)

1. Open Settings → Networks → Add network → Add a network manually.

2. Paste the table values above.

3. Save, then select Avalanche Fuji C-Chain.

4. Confirm the chain ID shows 43113 (not Avalanche mainnet 43114).

2. Get test AVAX

PoD two-way requests pay fees in AVAX on Fuji (msg.value). You need enough for deploy gas and Inbox fees.

Official options:

• Avalanche Core testnet faucet (C-Chain)

• Avalanche Builder Hub faucet

• Avalanche support note on faucets: Is there an AVAX faucet?

Faucets may require a mainnet AVAX balance, a Builder Hub account, or a coupon. Request C-Chain test AVAX (not only P-Chain).

After funding, your wallet AVAX balance on Fuji should be non-zero.

3. Configure your toolchain for Fuji

Use Node.js 18+. Install later when you start coding; for Day 0 you only need a network entry that targets Fuji.

Hardhat (hardhat.config.ts / .js)

import { HardhatUserConfig } from "hardhat/config";
import "@nomicfoundation/hardhat-ethers";

const FUJI_RPC = process.env.AVALANCHE_FUJI_RPC_URL
  ?? "https://api.avax-test.network/ext/bc/C/rpc";

const config: HardhatUserConfig = {
  solidity: "0.8.26",
  networks: {
    fuji: {
      url: FUJI_RPC,
      chainId: 43113,
      accounts: process.env.PRIVATE_KEY ? [process.env.PRIVATE_KEY] : [],
    },
  },
};

export default config;

Deploy later with:

npx hardhat run scripts/deploy.ts --network fuji

Foundry (foundry.toml)

[profile.default]
src = "src"
out = "out"
libs = ["lib"]
solc_version = "0.8.26"

[rpc_endpoints]
fuji = "${AVALANCHE_FUJI_RPC_URL}"

.env (example):

AVALANCHE_FUJI_RPC_URL=https://api.avax-test.network/ext/bc/C/rpc
PRIVATE_KEY=0x...

Broadcast later with --rpc-url fuji (or the resolved RPC URL) and chain ID 43113.

Packages you will install for PoD (not required yet)

When you start the adder tutorial:

npm install @coti-io/pod-sdk ethers
npm install github:coti-io/coti-contracts#main

• TypeScript: @coti-io/pod-sdk

• Solidity: @coti-io/coti-contracts (PodLib, PodUserFuji)

4. Smoke-test on SnowScan

1. From your funded Fuji wallet, send a small amount of AVAX to another address you control (or to yourself).

2. Open the tx on SnowScan testnet.

3. Confirm status success, network is Fuji, and the fee was paid in AVAX.

Optional RPC check:

curl -s -X POST https://api.avax-test.network/ext/bc/C/rpc \
  -H 'content-type: application/json' \
  --data '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}'

Expected result hex: 0xa869 (= decimal 43113).

5. PoD context (what comes next)

On Fuji your dApp talks to the shared Inbox:

0x3b8B70819f27e0438cBcE7f31894f799da52648F

Private compute still runs on COTI Testnet (7082400). Solidity preset: PodUserFuji.

Next	Link
Network + contract addresses	Avalanche Fuji
Fees in AVAX	How do PoA fees work on Avalanche Fuji?
First dApp	Tutorial: private Adder on Avalanche Fuji
Animated Fuji flow	pod.coti.io/avalanche

Checklist

• Wallet on Fuji C-Chain (43113)

• Test AVAX balance > 0

• Hardhat or Foundry has a fuji RPC / chainId: 43113

• At least one successful tx visible on SnowScan

• Ready for @coti-io/pod-sdk + @coti-io/coti-contracts