ImpulsAr is our Stellar GIVE Hackathon 2025 project. It lets KYC’d users request to list donation proposals. An admin reviews each request and, once approved, creates an on‑chain crowdfunding campaign secured by a Soroban smart contract with milestone-based releases. Donors contribute using a chosen token (e.g., XLM on Soroban). Funds can be refunded while a campaign is still running, and are withdrawn by milestone receivers only after judge approval.
- Team: ImpulsAr
- Core: Soroban smart contract in
contracts/contracts/baf-crowdfunding-contract - Language/SDK: Rust +
soroban-sdk = 22.0.0
- Listing workflow: users submit requests in the app. and an admin reviews and, if approved, creates the campaign on-chain by calling the contract.
- Milestone escrow: Each campaign defines milestones, each with an amount and receiver. Judges approve liberations; receivers withdraw only when the campaign is fully funded and the milestone is available and approved.
- Donor protections: Minimum donation enforced; refunds allowed while the campaign hasn’t completed; strict math checks avoid overflows/underflows.
sequenceDiagram
autonumber
participant U as User (Donor)
participant F as Frontend
participant B as Backend
participant A as Admin
participant J as Judge
participant C as Contract
U->>F: Submit listing request
F->>B: Store request
A->>B: Review + approve
A->>C: __constructor (once) / create_campaign
U->>C: contribute(campaignId, amount)
J->>C: approve_liberation(campaignId, milestoneId)
Note right of C: On full funding and approval
C-->>U: refundable until COMPLETE
Milestone Receiver->>C: withdraw(campaignId, milestoneId)
Prerequisites: Rust toolchain + Soroban target + Stellar CLI.
- Install the WASM target (choose one based on your rustc):
# rustc >= 1.85
rustup target add wasm32v1-none
# rustc < 1.85
rustup target add wasm32-unknown-unknown- Install the Stellar CLI:
cargo install --locked [email protected]- Build the contract:
# rustc >= 1.85
cargo build --manifest-path contracts/Cargo.toml --target wasm32v1-none --release
# rustc < 1.85
cargo build --manifest-path contracts/Cargo.toml --target wasm32-unknown-unknown --release- Optimize the WASM:
# adjust the path if using the other target
stellar contract optimize \
--wasm contracts/target/wasm32v1-none/release/baf_crowdfunding_contract.wasm- Prepare keys and asset on Testnet:
stellar keys generate --global admin --network testnet --fund
stellar contract asset id --asset native --network testnet # XLM asset id- Deploy and initialize:
stellar contract deploy \
--wasm contracts/target/wasm32v1-none/release/baf_crowdfunding_contract.optimized.wasm \
--source admin \
--network testnet \
-- \
--admin <G....ADMIN_PUBKEY> \
--token <XLM_ASSET_ID>Note: initialization sets the admin and which token the contract will accept.
__constructor(admin: Address, token: Address)create_campaign(campaign: Campaign)– admin‑onlyget_campaign(campaign_id: u32) -> Campaignget_max_campaign_index() -> u32contribute(contributor: Address, campaign_id: u32, amount: i128)– contributor‑authrefund(contributor: Address, campaign_id: u32)– contributor‑auth; not allowed once COMPLETEwithdraw(campaign_id: u32, milestone_id: u32)– requires milestone.receiver auth; allowed only after goal reached and milestone approved & availableadd_judge(user: Address)/remove_judge(user: Address)– admin‑onlyapprove_liberation(sender: Address, campaign_id: u32, milestone_id: u32)– judge‑only
Events: contract_initialized, add_campaign, add_contribute, refund, withdraw.
- All amounts are i128; the unit depends on the token’s decimals (for native XLM that’s stroops; 1 XLM = 10,000,000 stroops).
- The contract uses strict overflow/underflow checks and enforces minimum donation per campaign.
- Judges are stored by role; only judges can approve milestone liberations.