Real-time token streaming on Stellar. Send tokens that unlock continuously by the second — perfect for payroll, token vesting, and grants. Built on Soroban smart contracts.
Inspired by Streamflow on Solana.
Testnet deployment — connect a Freighter wallet set to Stellar testnet to try it.
Contract: CBNDCZTRFNTDAPQLPK2ESOKO4XFMSC4PX37QE75BBYFOYIEWIPMHAKFV (Testnet)
- Per-second unlocking — funds stream continuously, recipients withdraw anytime
- Cliff support — set a cliff date with an optional lump-sum unlock
- Cancel anytime — sender cancels and gets unstreamed tokens back, recipient keeps what unlocked
- Non-custodial — contract holds funds, no intermediary
- Multi-token — XLM, USDC, EURC (any SEP-41 token)
| Layer | Tech |
|---|---|
| Frontend | Next.js 16, React 19, Tailwind CSS 4, shadcn/ui |
| Smart Contract | Rust, Soroban SDK v26 |
| Blockchain | Stellar (Soroban) |
| Wallet | Freighter, xBull, LOBSTR (with WalletConnect v2 fallback), Albedo |
| RPC | Stellar Soroban Testnet RPC |
├── app/ # Next.js app router pages
│ └── app/ # Protected app area
│ ├── page.tsx # Dashboard
│ ├── streams/ # All streams list
│ ├── create/ # Create stream form
│ └── stream/[id]/ # Stream detail + withdraw/cancel
├── components/
│ ├── landing/ # Marketing landing page
│ ├── layout/ # Navbar, wallet button, auth gate
│ ├── streams/ # Stream card, stats, empty state
│ └── ui/ # shadcn/ui primitives
├── contracts/
│ └── streaming/ # Soroban smart contract (Rust)
│ └── src/
│ ├── lib.rs # Contract logic
│ ├── test.rs # Unit tests (13 tests)
│ └── test_security.rs # Security tests (31 tests)
├── hooks/ # useStreams, useContract, useWallet, useNow
├── lib/
│ ├── contract.ts # Contract integration layer
│ ├── stellar.ts # Network config + RPC client
│ ├── stream-utils.ts # Unlock math, formatters
│ └── mock-data.ts # Dev mock store
└── types/stream.ts # StreamData, TokenInfo, CreateStreamInput
The Soroban contract is at contracts/streaming/. Full API reference: see docs/api-reference.md.
| Function | Description |
|---|---|
create_stream |
Fund a new stream (requires prior approve on token) |
create_streams_batch |
Create multiple streams in one atomic transaction (up to 20 per batch) |
withdraw |
Recipient (or delegate) withdraws unlocked tokens |
cancel |
Sender cancels — recipient gets unlocked portion, sender gets remainder |
partial_cancel |
Sender reduces a stream's locked balance, releasing funds back |
transfer_stream |
Recipient transfers stream rights to another address |
top_up |
Sender adds additional funds to an active stream |
| Function | Description |
|---|---|
get_stream |
Read full stream details by ID |
get_withdrawable |
Current withdrawable amount for a stream |
get_sent_streams |
Paginated stream IDs sent by an address |
get_received_streams |
Paginated stream IDs received by an address |
get_sent_stream_count |
Total count of streams sent by an address |
get_received_stream_count |
Total count of streams received by an address |
get_archived_sent_streams |
Paginated archived (cancelled/completed) streams sent by an address |
get_archived_received_streams |
Paginated archived streams received by an address |
get_stream_metadata |
Read optional metadata (name, category, memo) for a stream |
| Function | Description |
|---|---|
update_stream_metadata |
Set optional metadata (name, category, memo) for a stream |
set_delegate |
Designate a delegate who can withdraw on the recipient's behalf |
remove_delegate |
Revoke delegation for a stream |
get_delegate |
Read the delegate address for a stream, if set |
cleanup_stream |
Either party removes a fully-drained or cancelled stream from storage |
bump_stream |
Extend the TTL of a stream's ledger data (anyone can call) |
| Function | Description |
|---|---|
initialize |
One-time contract initialization, sets admin address |
pause |
Prevent new stream creation (admin only) |
unpause |
Resume normal operations (admin only) |
upgrade |
Deploy a new contract wasm (admin only) |
migrate |
Post-upgrade data migration hook (admin only) |
version |
Get contract version number |
name |
Get contract name |
unlocked = cliffAmount + (elapsed × amountPerSecond)
Capped at depositedAmount. The cliff blocks any unlock until cliffTime is reached.
cd contracts
cargo test44 tests pass covering the full lifecycle, authorization, overdraw protection, cliff edge cases, integer math, and self-streams.
- Node.js 18+
- Freighter browser extension (set to Testnet)
npm install --legacy-peer-deps
npm run devOpen http://localhost:3000.
# .env.local
NEXT_PUBLIC_STREAM_CONTRACT_ID_TESTNET=CBNDCZTRFNTDAPQLPK2ESOKO4XFMSC4PX37QE75BBYFOYIEWIPMHAKFV
# NEXT_PUBLIC_STREAM_CONTRACT_ID_MAINNET=<your mainnet contract id>The contract is already deployed to testnet — use the value above as-is. The app reads
NEXT_PUBLIC_STREAM_CONTRACT_ID_TESTNET (or _MAINNET) depending on
NEXT_PUBLIC_STELLAR_NETWORK. If the variable is absent the app runs in mock mode
automatically (no wallet or testnet funds required); see Architecture notes.
# Install stellar-cli
cargo install stellar-cli --locked
# Generate a deployer key and fund it
stellar keys generate deployer --network testnet
stellar keys fund deployer --network testnet
# Build
cd contracts/streaming
stellar contract build
# Deploy
stellar contract deploy \
--wasm contracts/target/wasm32v1-none/release/flowstar_streaming.wasm \
--source deployer \
--network testnet- Install Freighter and switch to Testnet
- Fund your wallet at Stellar Laboratory Friendbot
- Open the app at
localhost:3000 - Connect Freighter → Create a stream → use this as the recipient address for testing:
GBWEDYWFGPNPAWCYOKWMCRPTR4IMV4SNZ7CVOZHPUXGHVXXPJSCFKVXQ
You'll sign two transactions: one approve on the token contract, then create_stream.
lib/contract.tsis the single integration boundary — mock mode is automatic:isMockMode = !config.streamContractId. SetNEXT_PUBLIC_STREAM_CONTRACT_ID_TESTNET(or_MAINNET) to connect to the real contract; omit it to run on mock data with no wallet needed- Stream unlock math runs client-side in
lib/stream-utils.tsfor live UI counters without polling - The contract uses
Persistentstorage with TTL extensions on every write (~30 days per stream) - All token amounts use
bigint(i128/u64) to match Soroban types exactly — no precision loss
Key design choices are documented in docs/adr/. Start there if you're wondering "why was it done this way?" before changing something fundamental.
Found a suspected vulnerability? Please report it privately rather than opening a public issue. See SECURITY.md for the supported scope, reporting process, response timeline, and safe harbor policy. We prefer private disclosure via GitHub Security Advisories.
Want to contribute? Read our Contributing Guide to get your local environment set up and learn the development workflow.
MIT