Base Ecosystem Integration

Horizon Protocol is built natively on Base L2 with deep integrations across the Coinbase/Base ecosystem.

Why Base?

We chose Base as our primary chain for:

• Low transaction costs - Affordable mission escrow operations
• Fast finality - Quick settlement for real-world coordination
• Coinbase ecosystem - Access to CDP, Paymaster, OnchainKit
• Growing user base - Established L2 with strong adoption
• EVM compatibility - Standard Solidity tooling

Coinbase Developer Platform (CDP)

Embedded Wallets

Users can create wallets via:

• Email signup - No seed phrase required
• Social login - Google, Apple, etc.
• Phone verification - SMS-based recovery

// CDP-powered wallet creation
const wallet = await cdpClient.evm.createAccount({
  name: `horizon-${userId}`,
});

Transaction Sponsorship (Paymaster)

Gas fees are sponsored for key operations:

Operation	Sponsored	User Pays
Rating attestations (EAS)	✅ Yes	$0
Achievement NFT minting	✅ Yes	$0
Mission creation	❌ No	Gas fee
Mission acceptance	❌ No	Gas fee

This enables seamless UX where users can rate and earn achievements without holding ETH.

Webhooks

Real-time event streaming from CDP:

• erc20_transfer - USDC payments
• transaction - Mission state changes
• wallet_activity - User wallet events
• onramp_transaction_completed - Fiat onboarding
• offramp_transaction_completed - Fiat offramp

// CDP webhook handler
async processEvent(event: CdpWebhookEvent) {
  switch (event.type) {
    case 'erc20_transfer':
      await this.handleErc20Transfer(event);
      break;
    case 'onramp_transaction_completed':
      // User successfully bought crypto
      break;
  }
}

---

Basenames Integration

Native support for .base.eth names:

Reverse Resolution

// Resolve address to Basename
const result = await basenameService.resolveAddress('0x...');
// Returns: { name: 'alice.base.eth', avatar: '...' }

Forward Resolution

// Resolve Basename to address
const address = await basenameService.resolveName('alice.base.eth');
// Returns: '0x...'

Identity Display

Users with Basenames get:

• Name displayed instead of 0x address
• Avatar from Basename profile
• ENS fallback if no Basename

---

EAS (Ethereum Attestation Service)

On-chain attestations on Base for:

Reputation Ratings

Every rating creates an immutable EAS attestation:

// Rating schema
bytes32 missionId,
address rater,
address ratee,
uint8 score,        // 1-5
string comment,
uint256 timestamp

Explorer: EAS Scan Base

Benefits

• Portable reputation - Works across any dApp reading EAS
• Verifiable - Anyone can check attestation validity
• Permanent - Cannot be deleted or modified
• Gasless - Sponsored via CDP Paymaster

---

USDC Payments

All mission escrow uses native USDC on Base:

Network	USDC Address
Base Mainnet	0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
Base Sepolia	0x036CbD53842c5426634e7929541eC2318f3dCF7e

Why USDC?

• Stable value - No volatility during mission execution
• Familiar - Users understand dollar amounts
• Liquid - Easy onramp/offramp via Coinbase
• Trustworthy - Circle-issued, regulated

---

Talent Protocol Integration

Builder reputation via Talent Protocol:

Builder Score

Users with Talent profiles get:

Level	Score Range	XP Multiplier
Novice	0-24	1.0x (no bonus)
Apprentice	25-49	1.05x (+5%)
Practitioner	50-74	1.10x (+10%)
Advanced	75-89	1.20x (+20%)
Expert	90-99	1.35x (+35%)
Master	100	1.50x (+50%)

Developer Leaderboard

Separate leaderboard for builders ranked by:

• Builder Score
• Completed missions
• Earned achievements
• Guild contributions

Mission Eligibility

Posters can require minimum Builder Score:

{
  "requirements": {
    "minBuilderScore": 50,
    "minBuilderLevel": "practitioner"
  }
}

---

Contract Deployments

Base Sepolia (Testnet)

Contract	Address
MissionFactory	0xee9234954b134c39c17a75482da78e46b16f466c
PaymentRouter	0x94fb7908257ec36f701d2605b51eefed4326ddf5
GuildFactory	0xfeae3538a4a1801e47b6d16104aa8586edb55f00
ReputationAttestations	0xedae9682a0fb6fb3c18d6865461f67db7d748002
DisputeResolver	0xb00ac4278129928aecc72541b0bcd69d94c1691e
HorizonAchievements	0x568e0e3102bfa1f4045d3f62559c0f9823b469bc

Base Mainnet

Mainnet deployment in progress. See Protocol Overview for updates.

---

OnchainKit Integration

The Horizon Mini App uses @coinbase/onchainkit for Base-native features:

import { OnchainKitProvider } from '@coinbase/onchainkit';
import {
  ConnectWallet,
  Wallet,
  WalletDropdown,
} from '@coinbase/onchainkit/wallet';
import {
  Transaction,
  TransactionButton,
} from '@coinbase/onchainkit/transaction';

Components Used

Component	Purpose
ConnectWallet	Wallet connection UI
WalletDropdown	Account management
Transaction	One-click transactions
TransactionButton	Gasless claim buttons
Identity	ENS/Basename display
Avatar	Profile pictures

---

Smart Wallet Support

Full support for Coinbase Smart Wallet (ERC-4337):

• Passkey authentication - Biometric login without seed phrases
• Account abstraction - Users don't need to manage gas
• Session keys - Smooth multi-transaction UX
• Recovery options - Social recovery built-in

// Mobile app configured for Smart Wallet
const walletConfig = {
  options: 'smartWalletOnly',
  // Paymaster for sponsored transactions
  paymasterUrl: process.env.CDP_PAYMASTER_URL,
};

---

Farcaster Integration

Social features powered by Farcaster:

Frame Support

The Mini App renders as a Farcaster Frame:

// layout.tsx meta tags
'fc:frame': 'vNext',
'fc:frame:image': '/og-image.png',
'fc:frame:button:1': 'Open Horizon',
'fc:frame:button:1:action': 'link',

Share to Warpcast

One-tap sharing of missions to Farcaster:

const farcasterUrl = `https://warpcast.com/~/compose?text=${shareText}&embeds[]=${shareUrl}`;

Social Graph

Friend activity feed based on Farcaster connections (in progress).

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Future Integrations

Planned additions:

• Base Bridge - Cross-chain asset support for multi-chain missions