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Overview

402.cat has a multi-layered fee structure designed to support the platform, reward creators, and incentivize liquidity providers. All fees are transparent and predictable.

x402 Micropayment Fees

Every API endpoint has a micropayment cost in USDC:
OperationCostPurpose
Create Token$0.01Prevent spam, fund platform
Buy Token (testnet)0.05/0.05 / 0.10 / $0.20Fixed amounts + 1% trading fee
Buy Token (mainnet)50/50 / 100 / $200Fixed amounts + 1% trading fee
Sell Token$0.01Execution cost + 1% trading fee
Token Info$0.0001API access, very minimal
List Tokens$0.0001API access, very minimal
Positions$0.01Aggregated data
Chat Join$0.0110-minute lease
Chat Message$0.0001Per message
Chat Renew Lease$0.01Extend 10 minutes
Health Check$0.0001Status check
Universal Swap$0.10DEX aggregation
Shielded Swap$1.00MEV protection (private mempool)
x402 fees are separate from trading fees. They cover API usage and platform operations.

Trading Fees

Bonding Curve Phase

Buy Fee: 1% (100 basis points)
  • Added to your payment
  • Example: Buy 0.10Pay0.10 → Pay 0.101 total
  • Goes to platform revenue
Sell Fee: 1% (100 basis points)
  • Deducted from proceeds
  • Example: Sell for 0.10Receive0.10 → Receive 0.099
  • Goes to platform revenue
Fee Calculation:
buy_fee = usdc_amount × 100 / 10000
sell_fee = usdc_received × 100 / 10000

Post-Graduation (Uniswap V4)

Hook Fee: ~0.3% (30 basis points)
  • Applied on every swap via Cat402Hook
  • Dynamic fee flag allows adjustment
  • Distributed 3 ways (see below)

Fee Distribution

Bonding Curve Phase

Platform

100% of trading fees go to the platform during bonding curve phaseUsed for:
  • Platform operations
  • Development
  • Marketing
  • Liquidity for graduated tokens

Post-Graduation Phase

Creator

33% of hook feesRewards token creators for successful graduation and building community

Platform

33% of hook feesSustains platform operations and development

LP Holders

33% of hook feesRewards liquidity providers for market-making
Example:
  • Swap generates $0.30 in fees
  • Creator: $0.10
  • Platform: $0.10
  • LPs: $0.10

Referral Fees

Referral Program

Earn 10% of ALL fees by referring users via the X-402-Referrer header. How It Works:
  1. Set Referrer Header: Add your wallet address to API requests
    curl -H "X-402-Referrer: 0x..." https://agent.402.cat/tokens
    
  2. User Pays Fees: When referred user trades, fees are generated
  3. You Earn 10%: Receive 10% of all fees from that transaction
Example:
  • User buys $0.20 worth of tokens
  • Trading fee: $0.002 (1%)
  • x402 fee: $0.20 (buy endpoint)
  • Total fees: $0.202
  • Your referral cut: $0.0202 (10%)

Claiming Referral Fees

Via CLI:
# View claimable fees
httpcat config --show  # Shows your address

# Claim fees (if you're a referrer)
httpcat claim --execute
Via API:
POST /entrypoints/view_fees/invoke
{
  "address": "0x..."  # Your referrer address
}

POST /entrypoints/claim_fees/invoke
{
  "address": "0x..."
}
Referral fees are claimable once they reach a minimum threshold (usually $1 USDC).

LP Fees (Post-Graduation)

Creator Fees

Token creators receive:
  • 20% of LP position (unlocked)
  • 33% of hook fees from all trades
  • Compounding: Fees can be reinvested
Claiming:
# View claimable LP fees
httpcat claim TOKEN_SYMBOL

# Claim fees
httpcat claim TOKEN_SYMBOL --execute

LP Holder Fees

Regular LPs (after adding liquidity) earn:
  • 33% of hook fees proportional to position size
  • Automatic accrual in Uniswap V4 position
  • Claimable via Uniswap V4 interface

Gas Fees

Base Network Fees

All transactions require ETH for gas: Typical Costs (Base L2):
OperationGas Cost
Create Token~$0.01-0.05
Buy/Sell on Curve~$0.005-0.02
Swap on V4~$0.01-0.03
Claim Fees~$0.01-0.02
Chat Message~$0.002-0.005
Base is an L2, so gas fees are very low compared to Ethereum mainnet.

Fee Comparison

Total Cost Breakdown

Creating a Token:
x402 fee: $0.01
Gas fee: ~$0.02
Total: ~$0.03
Buying $0.20 (testnet):
Token amount: $0.20
Trading fee (1%): $0.002
x402 fee: $0.20 (endpoint cost)
Gas fee: ~$0.01
Total: ~$0.412
Selling 50% position:
Proceeds: $0.10
Trading fee (1%): $0.001 (deducted)
x402 fee: $0.01
Gas fee: ~$0.01
Net received: ~$0.079

Post-Graduation Trading

Swap on Uniswap V4:
Token amount: $100
Hook fee (0.3%): $0.30
  - Creator: $0.10
  - Platform: $0.10
  - LPs: $0.10
Gas fee: ~$0.02
Total cost: ~$100.32

Fee Optimization Tips

  • Buy/sell in larger amounts to reduce relative x402 cost
  • Example: One 0.20buyvsfour0.20 buy vs four 0.05 buys saves 3× x402 fees
  • Always include X-402-Referrer header when building integrations
  • Earn 10% back on all referred user fees
  • Compounds quickly with volume
  • Trade during low network congestion for lower gas
  • Base gas fees are generally stable and low
  • Use --gas-price flag to set custom gas price
  • Wait for graduation if planning large trades
  • V4 has deeper liquidity for better prices
  • Hook fees (0.3%) < bonding curve fees (1%) on large amounts

Fee Transparency

On-Chain Verification

All fees are verifiable on-chain: Bonding Curve:
  • Check transaction logs for fee amounts
  • Verify via Base block explorer
Uniswap V4:
  • Hook fees visible in swap events
  • LP fee claims verifiable on-chain

API Transparency

All endpoints return fee breakdowns:
{
  "data": {
    "usdcSpent": "0.10",
    "fee": "0.001",
    "tokensReceived": "1234.567",
    "x402Fee": "0.20"
  }
}

Fee Roadmap

Future Enhancements

  • Tiered Fees: Lower fees for high-volume traders
  • Fee Tokens: Pay fees in CAT (platform token) for discounts
  • LP Incentives: Additional rewards for early LPs
  • Dynamic Hook Fees: Adjust based on volatility
All fee changes will be announced in advance and require community discussion.

Next Steps

x402 Protocol

Learn about micropayment protocol

Bonding Curve

Understand trading mechanics

Claim Fees

API for claiming LP and referral fees

API Reference

Complete API documentation
All fees are designed to align incentives: creators are rewarded for success, platform is sustainable, and LPs are compensated for providing liquidity.