Milestone Escrow
The client locks the full budget up front, split into milestones. Funds move only on release, arbiter decision or cancellation.
Solidity 0.8.28OpenZeppelin v5ETH / ERC-20
Gold-Backed Token (RWA)
Real-world-asset demo: 1 sGOLD = 1 gram of custodied gold, minting enforced against proof of reserve
ERC-20AccessControlProof of reserveFoundry
What it is
GoldBackedToken makes 1:1 backing a precondition instead of a promise: mint(to, amount) only succeeds if totalSupply + amount ≤ reserve(). The reserve is read from a proof-of-reserve feed whose interface is identical to Chainlink's AggregatorV3, validated for freshness and normalised to 18 decimals.
Holders redeem by burning tokens with an off-chain reference; the custodian watches the redemption events and delivers the metal or settles in cash. This is a demo — sGOLD is not backed by real gold, has no monetary value and is not offered for sale. It draws on our team's domain knowledge from building a platform for a precious-metals dealer.
The business problem
Tokenised commodities and stablecoins depend on one promise: every token is backed. When that promise is only checked by occasional attestations, an issuer can mint more than it holds — and nobody sees the under-collateralisation until it's too late.
How it works
- 1
The custodian (or a Chainlink proof-of-reserve feed) reports the grams of gold held.
- 2
The minter role mints tokens to a customer after payment — only if the new supply stays within the reserve.
- 3
Tokens trade freely as ERC-20, with EIP-2612 permit for gasless approvals.
- 4
A holder redeems by burning tokens with a reference; the custodian settles off-chain.
- 5
In an incident, the pauser role halts all transfers, mints and redemptions.
Security measures
- Minting reverts with InsufficientReserve if the supply would exceed the reserve
- Oracle validation: non-positive, missing, future or stale data is rejected
- Bounded staleness window (1 second to 7 days) — the check can't be switched off
- Decimal normalisation for any feed precision
- Role-based AccessControl
- Fuzzed invariant: totalSupply ≤ reserve
Features
- 1 token = 1 gram of gold
- Reserve-checked minting
- Chainlink AggregatorV3-compatible reserve feed
- Redemption by burn with reference
- Separate admin, minter and pauser roles
- Pausable circuit breaker
Typical use cases
- Tokenised precious metals, commodities and warehouse receipts
- Reserve-enforced stablecoins
- Other real-world assets with a verifiable off-chain registry
Known limitations
Demo only: a mock reserve feed stands in for a real oracle. Production would need a real proof-of-reserve feed, multisig + timelock admin and, where required, transfer restrictions (e.g. under MiCA).
Other showcase contracts
Token + Vesting + Staking
A capped ERC-20 with gasless approvals, vesting schedules with cliff for team and investors, and Synthetix-style staking rewards.
ERC-20EIP-2612OpenZeppelin v5
SigmaNFT Collection
A fair NFT launch: allowlist and public phases, per-wallet limits, immutable max supply, ERC-2981 royalties and a delayed reveal.
ERC-721ERC-2981Merkle proofs
Standards: Solidity 0.8.x, OpenZeppelin, Foundry tests with fuzzing, Slither static analysis, verified source. 223 tests · 100% coverage · Slither-analysed.
Have a project in mind?
Tell us what you're building. You get an honest assessment, a clear scope and a fixed-price or milestone proposal, usually within a few working days.
Prefer to write first? Write to us