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
Subscription Manager
Recurring ERC-20 subscriptions with pull payments and automatic revenue splits
ERC-20SafeERC20OpenZeppelin v5Foundry
What it is
SubscriptionManager is a non-custodial billing contract. Merchants create plans with a token, a price, a billing period and up to five revenue-share payees in basis points; the merchant receives the remainder.
Subscribers approve an allowance once and subscribe — the first period is charged immediately. When a period is due, anyone (a merchant backend, a keeper bot or Chainlink Automation) can trigger the charge. Funds move directly from subscriber to payees; the contract never holds a balance.
The business problem
Crypto payments are push-based: customers must sign a new transaction every month, which drives churn and manual follow-up. Revenue shares need separate payout runs, and custodial billing providers reintroduce counterparty risk.
How it works
- 1
The merchant creates a plan: token, price, period and optional revenue-share payees.
- 2
The subscriber approves an allowance (e.g. for 12 months) and subscribes; period 1 is charged.
- 3
When the next period is due, a keeper calls
charge(); the split is paid out and the next charge date advances. - 4
Subscriber or merchant can cancel at any time; the merchant can deactivate a plan.
Security measures
- At most one charge per period and no back-billing after a lapse (fuzz-tested)
- Immutable price and period — no surprise price increases
- Subscribers can cancel any time and cap exposure via their allowance
- Non-custodial: nothing to drain
- Exact splits — payouts sum exactly to the price (fuzzed)
- Bounded payees and minimum period; nonReentrant, SafeERC20
Features
- Merchant plans with immutable pricing
- Approve once, keeper-triggered charges
- Up to 5 revenue-share payees in basis points
- Cancel and deactivate
- Non-custodial — zero balance
Typical use cases
- Web3 SaaS and API access billed in stablecoins
- Creator memberships with automatic splits
- B2B retainers with reseller commissions
Known limitations
Fee-on-transfer and rebasing tokens are not supported. A charge fails without state changes if allowance or balance is too low; the keeper can retry.
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