Staking

Technical documentation for StakeChain — the Zentachain staking smart contract system.

Verified Contracts

All contracts are deployed on Ethereum mainnet and verified on Etherscan.

Contract	Address	Etherscan
Zentachain	0x6B58cfBEdCfe7C59d456c864c92257910A61D8FC	View
StakeChain	0xC00D35881e66E9eCC116De9696Ae12A18104B106	View
Zentanode	0x5a427e6aA609509C6EE089502a048f17B4895a9b	View

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Overview

StakeChain is the staking smart contract that allows CHAIN token holders to stake their tokens in configurable pools and earn rewards. Rewards are minted directly to stakers — there is no pre-funded reward pool.

The contract is built on Solidity ^0.8.28 with OpenZeppelin v5.2.0 libraries and includes reentrancy protection, timestamp manipulation safeguards, and owner-controlled administration.

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Live Staking Pools

Three staking pools are currently active on mainnet:

Pool	APR	Min Stake	Max Stake	Pool Size	Claim Lock	Unstake Lock
0	12%	1,000 CHAIN	10,000 CHAIN	100,000 CHAIN	1 day	7 days
1	16%	2,000 CHAIN	20,000 CHAIN	200,000 CHAIN	1 day	14 days
2	20%	5,000 CHAIN	50,000 CHAIN	500,000 CHAIN	1 day	28 days

Higher APR pools require larger minimum stakes and longer lock-up periods.

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Pool System

Each staking pool is an independent configuration with its own parameters:

Parameter	Description
APR	Annual Percentage Rate in basis points (1600 = 16%)
Minimum Stake Amount	Lowest amount a user can stake
Maximum Stake Per User	Cap on individual stakes
Pool Size Limit	Maximum total tokens in the pool
Claim Time Lock	Minimum time between reward claims (1 day)
Unstake Time Lock	Minimum time before withdrawal allowed

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Staking

Standard Staking

Two-transaction process:

1. Approve — User approves the StakeChain contract to spend their CHAIN tokens

2. Stake — Call stake(poolId, amount) to deposit tokens into a pool

Permit-Based Staking

Single-transaction process using ERC-2612 permit signatures:

• Call stakeWithPermit(poolId, amount, deadline, v, r, s)

• Combines approval and staking in one transaction

• Saves gas and improves UX

Compound Staking

Users can add more tokens to an existing stake at any time:

• Previous rewards are preserved and continue accruing

• The unstake timer resets for the entire staked amount

• New rewards begin accruing on the combined amount

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Rewards

Calculation

Rewards are calculated based on time elapsed and the pool's APR:

Annual Rewards = (Staked Amount × APR) / 10,000
Rewards Per Second = Annual Rewards / 31,536,000
Earned = Rewards Per Second × Time Elapsed

Key details:

• APR is stored in basis points (1200 = 12%, 1600 = 16%, 2000 = 20%)

• A 15-minute timestamp buffer is applied to prevent manipulation

• Rewards are minted to the user (inflationary), not drawn from a pool

Claiming

• User calls claimRewards(poolId)

• Claim time lock (1 day) must have elapsed since last claim

• Pool must not be paused

• Rewards are minted directly to the user's wallet

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Unstaking

Standard Unstake

• Unstake time lock must have elapsed since staking (7/14/28 days depending on pool)

• Returns full staked amount plus any unclaimed rewards

• Removes user from the pool

Emergency Unstake

• Only available when emergency mode is enabled for the pool

• Bypasses time lock restrictions

• Returns staked amount plus accumulated rewards

• Emergency mode has a 24-hour toggle cooldown to prevent abuse

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Security

Feature	Implementation
Reentrancy Protection	nonReentrant modifier on all external calls
No Contract Interaction	noContracts modifier blocks smart contract callers
APR Change Delay	48-hour delay prevents front-running
Timestamp Buffer	15-minute buffer reduces manipulation window
Emergency Cooldown	24-hour cooldown on emergency toggle
Pause Mechanism	Pools can be paused individually
Max Stake Limits	Per-user cap enforcement per pool

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Testing & Audit

Metric	Value
Test Cases	152 passing (100% coverage)
Test Files	18 dedicated test files
Security Rating	9.2 / 10
Code Quality	9.0 / 10
Gas Efficiency	8.5 / 10
Solidity Version	^0.8.28
OpenZeppelin Version	5.2.0
Framework	Hardhat + Chai

Security Tests Include

• Access control enforcement

• Staking limits and pool size enforcement

• Timelock mechanism validation

• Emergency function testing

• Reward calculation precision and edge cases

• APR change protection (48-hour delay, front-running prevention)

• Timestamp manipulation protection

• Pool deletion safety (only when empty)

• Emergency toggle rate limiting

• Permit-based staking validation

• Deployment integrity verification

Security Verification Matrix

Check	Zentachain	StakeChain	Zentanode
Reentrancy Protection	Passed	Passed	Passed
Access Control	Passed	Passed	Passed
Input Validation	Passed	Passed	Passed
Integer Overflow	Passed	Passed	Passed
Emergency Pause	Passed	Passed	Passed
Time Manipulation	Passed	Passed	Passed
Front-running Protection	Passed	Passed	Passed
Rate Limiting	Passed	Passed	Passed

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APR Changes

To prevent front-running:

1. Owner schedules an APR change via scheduleAPRChange(poolId, newAPR)

2. A 48-hour delay period begins

3. After the delay, anyone can call applyPendingAPRChange(poolId) to activate it

4. All changes are publicly visible on-chain

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View Functions

Function	Returns
getPoolInfo(id)	Complete pool configuration
getUserStakeInfo(address, id)	User's staked amount, rewards, timestamps
getUserRewards(address, poolId)	Accumulated unclaimed rewards
getUnstakeUnlockTimestamp(address, poolId)	When unstake becomes available
getClaimUnlockTimestamp(address, poolId)	When next claim is available
getPoolStatus(poolId)	Whether pool is paused
getPoolEmergencyStatus(poolId)	Whether emergency mode is active
getMaximumStakeStatus(poolId)	Whether max stake is enforced
getPendingAPRChange(poolId)	Scheduled APR change details

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Token Contract

Property	Value
Name	Zentachain
Symbol	CHAIN
Standard	ERC-20
Decimals	12
Total Supply	5,000,000
Features	Burnable, Pausable, Permit (EIP-2612)
Address	0x6B58cfBEdCfe7C59d456c864c92257910A61D8FC

StakeChain and Zentanode are both whitelisted as minters on the CHAIN token contract, allowing them to mint reward tokens directly.

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Zentanode Rewards Contract

A separate contract (Zentanode.sol) handles node operator rewards independently from StakeChain:

Parameter	Value
Address	0x5a427e6aA609509C6EE089502a048f17B4895a9b
Rewards Per Claim	25 CHAIN (configurable, max 1,000)
Claim Duration	31 days
Slash Duration	15 days
Daily Mint Limit	100,000 CHAIN
Access	Allowlist-based

Node operators are added to the allowlist and can claim rewards at regular intervals. The contract includes a slashing mechanism for misbehaving nodes and pro-rated partial rewards for operator removal.