Gas Sponsorship

Overview

Gas sponsored swaps on Solana enable users to execute token swaps without needing to hold sufficient SOL for transaction fees and rent exemption requirements. Blink's Solana gas sponsorship solution addresses the unique challenges of the Solana blockchain, including rent exemption minimums and transaction bundling complexities.

Solana-Specific Use Cases

Primary Use Cases

• No SOL Holdings: Users hold tokens like USDC, BONK, or other SPL tokens but have zero SOL balance

• Insufficient SOL for Rent: Users have some SOL but not enough to cover both transaction fees and maintain rent exemption after the swap

• CEX-to-Wallet Onboarding: Users transferring assets from centralized exchanges who receive tokens but no SOL for transaction fees

• Cross-Chain Bridge Recipients: Users receiving tokens from other chains who lack SOL for subsequent transactions

Common Scenarios

• User holds 1,000 USDC but 0 SOL and wants to swap to another token

• User has 0.001 SOL (enough for fees) but swapping would drop them below rent exemption threshold

• New user receives airdropped tokens but has never held SOL

How Solana Gas Sponsorship Works

Sponsorship Activation

Gas sponsorship can be enabled through:

• Request Flag: Including a sponsorable: true parameter in the swap request

• Wallet Configuration: Pre-configured sponsorship settings agreed with the Blink Team

Jito Bundle Integration

Blink leverages Jito bundles to ensure transaction reliability and cost efficiency:

1. Pre-execution Validation: Transactions are simulated within the bundle environment before execution

2. Atomic Execution: SOL transfer and user swap execute atomically in the same bundle

3. Revert Protection: Failed transactions don't consume sponsored SOL, protecting against unnecessary costs

Sponsored Transaction Process

1. Transaction Analysis: Blink detects insufficient SOL for transaction execution

2. Rent Exemption Calculation: System calculates minimum SOL needed for rent exemption post-swap

3. Bundle Simulation: Complete transaction bundle is simulated to ensure success

4. SOL Transfer: Required SOL amount is transferred to user's wallet within the bundle

5. Swap Execution: User's swap transaction executes immediately after SOL transfer

Solana Rent Exemption Considerations

Rent Exemption Requirements

Solana accounts must maintain a minimum SOL balance to remain "rent exempt." This creates additional complexity for gas sponsorship:

• Minimum Balance: Typically ~0.00203928 SOL per account

• Post-Swap Balance: Users must retain sufficient SOL after transaction fees

• Token Account Creation: New token accounts require additional rent exemption SOL

Blink's Rent Exemption Handling

• Comprehensive Calculation: Blink calculates total SOL needed including transaction fees AND rent exemption

• Account Analysis: System checks if new token accounts will be created during the swap

• Buffer Provision: Ensures users maintain rent exemption status after transaction completion

Cost Structure Example

Required SOL = Transaction Fee + Rent Exemption Buffer + New Account Rent (if applicable)
- Transaction Fee: ~0.000005 SOL
- Rent Exemption: ~0.00203928 SOL  
- New Token Account: ~0.00203928 SOL (if creating new account)
Total: ~0.004084 SOL minimum

Fee and Revenue Model

Threshold Configuration

Wallets can configure gas sponsorship thresholds to ensure profitability:

Sponsorship Condition: Swap Fee Revenue ≥ (SOL Transfer Cost + Rent Exemption Cost)

Revenue Optimization

• Dynamic Thresholds: Adjust sponsorship thresholds based on SOL price volatility

• Fee Markup: Wallets can add premium swap fees for sponsored transactions

• Volume Incentives: Higher swap volumes can justify lower thresholds

Example Scenario

User Swap: $10,000 USDC → BONK
Wallet Fee: 0.5% = $50
Required SOL: 0.004084 SOL (~$0.80 at $200/SOL)
Net Revenue: $50 - $0.80 = $49.20
Sponsorship Decision: ✅ Profitable

Implementation Details

API Integration

No additional technical integration required. Existing Blink swap endpoints automatically handle:

• SOL balance detection

• Rent exemption calculation

• Bundle creation and execution

• Revenue tracking and reporting