# TL;DR: Putting out a challenge for teams to code a backstop liquidity smart contract for hINJ→INJ liquidation. Reward: 1500 INJ (~USD 30K notional, INJ price: 20.14) Before you actually start working on the bounty, please register by sending your proposal to Injective via email ( **rfp@injective.foundation** ). # Overview Create a smart contract that facilitates a fixed-rate swap mechanism between two tokens (Token A and Token B), with designated roles for liquidity providers and swap executors. The contract should maintain a pool of Token A that can be swapped for Token B at a predetermined rate, serving as a backstop liquidity solution during high-demand periods or market stress. # Background Backstop liquidity mechanisms are crucial for maintaining market stability, especially during periods of high volatility or large liquidation events. This contract will serve as a guaranteed liquidity source with a fixed swap rate, ensuring that there's always available liquidity at a known price point for certain tokens. # Core Requirements *Role-Based Access Control* 1. Party A (Liquidity Provider): - Must be able to supply Token A to the contract - Can withdraw both Token A and Token B from the contract - Can set and update the swap rate - Can manage whitelist of Party B addresses - Should be set during contract instantiation 2. Party B (Swap Executor): - Must be whitelisted by Party A - Can execute swaps up to available liquidity - Can query contract state and swap parameters - Cannot modify contract parameters *Functionality* 1. Liquidity Management: - Implementation of deposit function for Token A - Implementation of withdrawal functions for both tokens - Tracking of total liquidity supplied - Prevention of unauthorized withdrawals 2. Swap Mechanism: - Fixed-rate swap execution - Validation of available liquidity before swap - Proper accounting of swapped amounts - Prevention of swaps when insufficient liquidity 3. Rate Management: - Ability to set and update swap rates - Rate validation to prevent invalid values - Rate querying functionality 4. Whitelist Management: - Functions to add/remove Party B addresses - Validation of whitelist status before swaps - Proper access control for whitelist management *Implementation Requirements* 1. Contract Structure: - Use CosmWasm standard contract structure - Implement proper error handling and custom errors - Include comprehensive testing suite - Follow CosmWasm best practices for state management 2. Security Considerations: - Implement proper access control checks - Include reentrancy protection - Add proper validation for all inputs - Handle decimal precision carefully - Include emergency pause functionality 3. Testing Requirements: - Unit tests for all main functions - Integration tests for common workflows - Error case testing - Proper mock implementations for CW20 tokens *Bonus Features* 1. Rate Limits: - Implement maximum swap amount per transaction - Add daily/weekly swap limits per address 2. Enhanced Analytics: - Track historical swap volumes - Implement swap history queries - Add liquidity utilization metrics 3. Advanced Features: - Multiple token pair support - Tiered whitelist system - Fee mechanism for swaps - Time-weighted average price calculation *Evaluation Criteria* 1. Code Quality: - Clean, well-documented code - Proper error handling - Efficient state management - Gas optimization 2. Security: - Proper access controls - Input validation - Safe mathematical operations - Protection against common attack vectors 3. Testing: - Comprehensive test coverage - Edge case handling - Proper mock implementations - Integration test scenarios 4. Documentation