FAQ

Why is there no keeper bot? Because the vault schedules its own checks through the Hedera Schedule Service (HIP-1215). When a sweep runs it books the next one, so the chain of checks continues with nothing off-chain staying online. The only "operator" cost is the HBAR budget each order prepays.

What happens if the checks stop? A market can stall if the Schedule Service's per-second capacity is full when a sweep tries to rebook, or if a gas-price spike outruns the cost model's margin. The market then reads Stalled, the UI shows "Checks stopped", and anyone can call restartSweep to resume it — it is permissionless and costs only the scheduling fee. See "A residual stall is recoverable, not preventable" in ARCHITECTURE.md.

Why doesn't an HBAR/USDC order fill on testnet? The only testnet HBAR/USDC pool trades ~19× away from Chainlink, so the guard correctly refuses the fill — that is the guard doing its job, not a bug. The DAI/USDC pool tracks Chainlink (~23 bps), so DAI stop-losses fill. On a mainnet fork the HBAR/USDC pool is arbitraged and the same guard opens (yarn foundry:fork-guard).

What does an order cost? A fixed scheduleCall network fee of about $0.12 per scheduled check dominates; gas is the rest. You prepay a budget in HBAR sized to the order's expected number of checks; unused budget is refunded when the order fills or is cancelled. The Trade page shows the budget and an upper-bound fee before you place. See "What an order costs" in the README.

Can I add a new market or a new order type? A new market is a config entry plus listMarket (README "Extending the vault"). Pluggable order types (with a trailing stop as the example) are designed in PLUGINS-DESIGN.md.

Is it audited? Can I use it on mainnet? It is a template, not an audited production system — treat it as a starting point. Before mainnet, work through MAINNET-CHECKLIST.md (mainnet addresses, feed heartbeats, a real WalletConnect id, cost recalibration, an audit).

Do I need to run an indexer or a backend? No. Reads come from the public mirror node and the JSON-RPC relay; the frontend is static. The only thing that must exist is the deployed vault.

Who can cancel or collect an order? Whoever holds the order NFT. Transferring the NFT transfers the right to cancel and the fill proceeds. If you send the NFT to the vault itself, the order becomes unclaimable — don't.

Why ECDSA keys, not ED25519? The EVM tooling (relay, browser wallet, deploy scripts) signs with an ECDSA (secp256k1) key, which has a matching 0x EVM address. ED25519 accounts work on Hedera but not through this EVM path.

There's no local chain — how do I test? Anvil has none of Hedera's system contracts (0x16b, 0x167, 0x168), so the unit/fuzz/invariant suites etch mocks of them, and the fork suites read the real testnet (and, opt-in, mainnet) contracts. See the README "Tests" section.