Ratings API

On-chain reputation attestations using EAS (Ethereum Attestation Service).

Overview

All ratings in Horizon are attested on-chain via EAS on Base L2. This provides:

• Permanent record of reputation
• Verifiable on any block explorer
• Portable across dApps
• Gasless via CDP Paymaster sponsorship

Endpoints

Submit Rating

POST /ratings/mission/:missionId

Submit a rating after mission completion. Creates an on-chain EAS attestation.

Request Body

{
  "score": 5,
  "comment": "Excellent work, delivered on time!"
}

Response

{
  "id": "rating123",
  "missionId": "mission123",
  "raterId": "user456",
  "rateeId": "user789",
  "score": 5,
  "comment": "Excellent work, delivered on time!",
  "signature": "0x...",
  "easUid": "0x1234567890abcdef...",
  "onChainTxHash": "0xabc123...",
  "isOnChain": true,
  "explorerUrl": "https://base-sepolia.easscan.org/attestation/view/0x...",
  "createdAt": "2025-12-01T10:00:00Z"
}

---

Get Mission Ratings

GET /ratings/mission/:missionId

Get all ratings for a specific mission.

Response

[
  {
    "id": "rating123",
    "rater": {
      "id": "user456",
      "displayName": "João",
      "evmAddress": "0x..."
    },
    "ratee": {
      "id": "user789",
      "displayName": "Maria",
      "evmAddress": "0x..."
    },
    "score": 5,
    "comment": "Excellent!",
    "easUid": "0x...",
    "isOnChain": true,
    "createdAt": "2025-12-01T10:00:00Z"
  }
]

---

Get User Rating Stats

GET /ratings/user/:userId/stats

Get aggregated rating statistics for a user.

Response

{
  "userId": "user789",
  "averageScore": 4.8,
  "totalRatings": 156,
  "ratingDistribution": {
    "5": 120,
    "4": 28,
    "3": 6,
    "2": 1,
    "1": 1
  },
  "asPerformer": {
    "average": 4.9,
    "count": 134
  },
  "asPoster": {
    "average": 4.6,
    "count": 22
  }
}

---

Verify Rating On-Chain

GET /ratings/:id/verify

Verify a rating's on-chain attestation status.

Response

{
  "id": "rating123",
  "easUid": "0x1234567890abcdef...",
  "isOnChain": true,
  "verified": true,
  "attestation": {
    "schemaId": "0x...",
    "recipient": "0x...",
    "attester": "0x...",
    "time": 1704067200,
    "revocable": false
  },
  "explorerUrl": "https://base-sepolia.easscan.org/attestation/view/0x..."
}

---

EAS Schema

Ratings use a custom EAS schema on Base:

bytes32 missionId,
address rater,
address ratee,
uint8 score,
string comment,
uint256 timestamp

Schema UID

Network	Schema UID
Base Sepolia	0x... (see deployment docs)
Base Mainnet	Coming soon

---

Gasless Attestations

Rating attestations are gas-sponsored via Coinbase Developer Platform:

1. User submits rating via API
2. Backend signs EAS attestation request
3. CDP Paymaster sponsors the transaction gas
4. Attestation recorded on Base L2
5. User pays $0 in gas fees

This enables seamless UX where users can rate without holding ETH for gas.

---

Reputation Impact

Ratings affect user reputation score:

Rating	Reputation Impact
5 stars	+5 reputation
4 stars	+2 reputation
3 stars	0 (neutral)
2 stars	-3 reputation
1 star	-5 reputation

Reputation is used for:

• Mission eligibility requirements
• Guild membership criteria
• Feed ranking algorithm
• Trust indicators in UI