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Sargas (v2.50.4-ovm)

Published: Oct 12, 2021

Codebase: v2.50.4-ovm


Wezen (v2.49.0)

Published: Sep 20, 2021

Codebase: v2.49.0

  • SIP-158 Deprecate Inverse Synths: This SIP will deprecate all iSynths (which have already been frozen for some time) in favor of synth shorting.
  • SIP-169 Deprecate Low Volume L1 Synths: Deprecates a number of synths with relatively low usage on L1 (see here for more details).

Mirfak (v2.48.0)

Published: Sep 14, 2021

Codebase: v2.48.0

  • SIP-142 Deprecating EtherCollateral loans: Will officially deprecate old loan contracts that have already been wound down.
  • SIP-145 Debt Cache Event Consistency: Fixes an incorrect debt cache event value.
  • SIP-170 Inflation Diversion for L2 Incentives: Directs part of SNX inflation to L2 staking rewards.
  • SIP-174 Redeem Deprecated Synths: Creates a synth redeemer contract that allows holders of deprecated synths to redeem them for sUSD at a frozen price from the time of deprecation. Note that no synths will be deprecated during this release.


Alnitak (v2.46.0-ovm)

Published: Jul 1, 2021

Codebase: v2.46.0-ovm


Alioth (v2.45.0)

Published: May 13, 2021

Codebase: v2.45.0


Alnair (v2.44.0)

Published: May 11, 2021

Codebase: v2.44.0

  • SIP-116 Upgrading deposit and withdrawal interface to Optimism's new interfaces
  • SIP-117 Support for exchanging on L2
  • SIP-118 Support for conditional fee reclamation


Regor (v2.43.0)

Published: Apr 29, 2021

Codebase: v2.43.0

SIP 115: Add sMSFT equity synth SIP 128: Add sCOIN equity synth

(No audit required, no new contract changes)

Alnilam (v2.42.0)

Published: Apr 22, 2021

Codebase: v2.42.0


Miaplacidus (v2.41.0)

Published: Mar 24, 2021

Codebase: v2.41.0

  • SIP-113 Re-enable sKRW (Korean Won)

(No audit required, no new contract changes)

Elnath (v2.39.0)

Published: Feb 11, 2021

Codebase: v2.39.0

(No audit required, no new contract changes)

Bellatrix (v2.38.0)

Published: Feb 4, 2021

Codebase: v2.38.0


Gacrux (v2.37.0)

Published: Jan 17, 2021

Codebase: v2.37.0

(No blog post)

No audit - reused older audited contract to fix debt issue on L2 caused by skewed pool from initial test involving 1 wei.

Castor (v2.36.1)

Published: Jan 15, 2021

Codebase: v2.36.1

  • SIP-60: New Escrow Contract & Migration
  • SIP-102 Support SNX on L2 with Optimism
  • SIP-105 Multi-collateral Liquidation Bug Fix


Shaula (v2.35.2)

Published: Dec 24, 2020

Codebase: v2.35.2

  • SIP-97: Multi-collateral loans β€” This SIP allows users to borrow Synths against ETH and ERC20 collateral. Initially, the system will support borrowing sUSD or sETH against ETH, and sUSD or sBTC against renBTC.
  • SIP-100: Resolver and cache improvements β€” Improves the β€˜AddressResolver’ to improve protocol upgrades, reduce gas of deployments and further decentralization.
  • SIP-103: sUSD shorts β€” This SIP allows users to short Synths against sUSD. This mechanism provides an alternative to iSynths for users seeking inverse price exposure. While these positions require collateral, they return the sUSD proceeds of the sale to the shorter, which can then be deployed productively throughout DeFi.


Adhara (v2.34.0)

Published: Dec 1, 2020

Codebase: v2.34.0

SIP-98 Re-implement double exchange fee rate on swing trades

Audit: (report combined with Shaula release)

Regulus (v2.32.2)

Published: Nov 13, 2020

Codebase: v2.32.2

  • SIP-94 Virtual Synth Fix to Ensure Settlement Is Connected

Audit: (bundled with Mimosa report)

Mimosa (v2.31.1)

Published: Nov 12, 2020

Codebase: v2.31.1

  • SIP-89 Virtual Synths
  • SIP-91 Debt Cache Contract
  • SIP-92 Historical iSynths Pricing Tracks When Last Frozen


Deneb (v2.30.0)

Published: Oct 8, 2020

Codebase: v2.30.0

  • SIP-83: Total Issued Synths (Debt pool) Snapshots
  • SIP-88: ExchangeRates patch - Chainlink aggregator V2V3
  • SCCP-51: Update sDEFI index
  • Resume synths paused previously by SIP-84


Fomalhaut (v2.28.4)

Published: Sep 24, 2020

Codebase: v2.28.4

  • SIP-77: Staking rewards contract
  • SIP-85: EtherCollateral for sUSD Loans
  • SIP-86: SIP 86: ExchangeRates Chainlink Aggregator V2V3
  • SIP-87: Add iETH incentive to RewardsDistribution


Pollux (v2.27.2)

Published: Sep 1, 2020

Codebase: v2.27.2

  • SIP-36: Chainlink Phase 2
  • SIP-63: Trading and volume incentives
  • SIP-64: Flexible contract storage
  • SIP-75: Freezing iSynths with public function with SNX reward
  • SIP-76: Chainlink warning flags integration
  • SIP-78: Reset iSynth does not trigger circuit breaker from SIP-65
  • SIP-84: Pause Synths Below Open Interest Threshold
  • SCCP-43: As part of the Pollux deployment and transition to Chainlink Oracles a number of SCCP controlled variables need to be updated to improve trading UX and reduce front-running attacks.


Spica (v2.26.2)

Published: Jul 30, 2020

Codebase: v2.26.2

  • SIP-54 : Limit Orders
  • SIP-65 : Decentralized circuit breaker
  • SIP-69 : New Index Synths
  • SIP-58 : Emit individual Reclaim and Rebate events
  • SIP-44 : Settlement Improvements β€” Minor modifications to the settlement process for exchange rates deployments.
  • SCCP-27 : Ether collateral second trial β€” Now that the first Ether collateral trial is complete, we will be launching a second trial that incorporates the collateralization ratio update from 150% to 125%.


Antares (v2.25.0)

Published: Jul 20, 2020

Codebase: v2.25.0

Implements most of SIP-71:

  • Allow market creators to cancel a market if no bids have been placed on it yet
  • Allow market creators to disable bid withdrawals at market creation
  • Emit bid events for the initial capital at market creation
  • Fix a bug that prevents creators from exercising their options before expiry under certain circumstances

Aldebaran (v2.24.0)

Published: Jul 1, 2020

Codebase: v2.24.0

  • SIP-66 Reduce gas of SNX transfers for non-stakers

Acrux (v2.23.3)

Published: Jun 30, 2020

Codebase: v2.23.3

  • SIP-48 Allow read views while rates are stale
  • SIP-53 Binary options


Altair (v2.22.4)

Published: Jun 5, 2020

Codebase: v2.22.4


Hadar (v2.21.6)

Published: Mar 31, 2020

Codebase: v2.21.6

  • SIP-9 One week claim window

  • SIP-10 Improved Delegation Powers

  • SIP-21 Deprecate swing fee

  • SIP-44 System & Synth Disabling

  • SIP-46 Address resolver gas optimizations

  • SIP-47 Prevent empty exchanges



Betelgeuse (v2.20.0)

Published: Feb 28, 2020

Codebase: v2.20.0


Achernar (v2.19.6)

Published: Feb 20, 2020

Codebase: v2.19.6

  • SIP-31: sETH pool automatic rewards β€” SNX rewards for providing sETH/ETH liquidity on Uniswap are currently paid out manually using a multisig. Using an automated system will be far more efficient and reduce the possibility of human error. Liquidity providers will now have to claim their rewards from a smart contract (no timeframe requirement).
  • SIP-33: Removal of XDRs β€” The XDR Synth was originally used as the base unit of account, but sUSD now fills that role. Taking out XDR will simplify several functions for users, particularly the payment of trading fees.
  • SIP-35: Skinny Ether collateral β€” There has been significant demand from the crypto community for ETH to be enabled as collateral in Synthetix. The three-month trial will reduce friction for new traders.
  • SIP-37: Fee reclamations and rebates β€” This SIP implements anti-frontrunning measures, ensuring that traders cannot profit from Oracle latency.
  • SIP-38: Charge fees during purge β€” This SIP adds a trading fee to when a Synth holder gets purged out of a Synth, to prevent users from camping out in these Synths without paying their fair share of fees. Synthetix.Exchange v2 β€” We are launching a new version of Synthetix.Exchange. V2 will move to production from beta as part of the Achernar release.
  • SIP-43: Adding an AddressResolver contract for better inter-contract communication within Synthetix
  • SCCP-11: Reduce trading fee to 0.3% β€” As part of the fee reclamation release, we’ll be reducing the trading fee back down to 30bps.
  • SCCP-12: Reactivate previously deactivated Synths β€” s/iXTZ, s/iBNB, and s/iLTC were all previously deactivated as they were being targeted by frontrunners, but we're reinstating them in the Achernar release.
  • SCCP-13: Reinstate fee claim buffer to 750% from 500% β€” The requirement to claim fees was reduced from 750% to 500% to allow stakers to not get hit by the temporary fee increase.



Procyon (v2.17.6)

Published: Dec 18, 2019

Codebase: v2.17.6

Capella (v2.16.4)

Published: Dec 12, 2019

Codebase: v2.16.4

DappMaintenance contract (v2.15.0)

Published: Dec 9, 2019

Codebase: v2.15.0

The DappMaintenance contract is here to keep a state of the dApps (Mintr and Synthetix Exchange) in order to check if they are supposed to be up or down.

Vega (v2.14.0)

Published: Nov 27, 2019

Codebase: v2.14.0

Arcturus (v2.13.1)

Published: Nov 21, 2019

Codebase: v2.13.1

Rigil (v2.12.2)

Published: Nov 8, 2019

Codebase: v2.12.2

  • SIP-21: This will double the exchange fee when changing between an s-Synth and an i-Synth, or vice versa, e.g. sTRX <> iBTC; or iTRX <> sBTC. The only Synth excluded is sUSD. There is already a leveraged benefit on the inverse Synths and currently being able to trade short <> long in a volatile market is a continuous advantage to front runners. The normal exchange fee rate is 30 bips (0.3%). However, it is currently 50 bips, which would make the swing trade 100 bips. When it is restored to 30 bips it would then only be 60 bips on a swing trade.
  • SIP-25: This SIP will decouple the gas limiter from the oracle. Currently, any invocation of the setGasPriceLimit() function has to be mined before a price update can be mined on-chain. This creates an unnecessary delay in serving timely oracle updates. This proposal is to change this access to setting the gasPriceLimit to a separate address, controlled by a setter only callable by the owner.
  • SIP-26: This is a bug fix that would reduce the gas estimation of trading SNX via Uniswap down from 900K to 100K.
  • SCCP-5: This change will divert 5% of the weekly SNX inflation into the arb pool β€” an increase from 2%. This is intended to provide a tighter sETH peg.
  • SCCP-6: This SCCP will reduce the C-Ratio buffer to 1% from 10%. The buffer was originally implemented as a protection mechanism for slashing of fees, as fee slashing is no longer implemented there is no need for such a high buffer, as it only needs to protect from minor price fluctuations. The previous 10% buffer meant a C-Ratio of ~682% was required to claim fees, while the new 1% buffer means a C-Ratio of ~742.6% is required.

Canopus (v2.11.2)

Published: Oct 4, 2019

Codebase: v2.11.2

  • SIP-8: This SIP formalises the sETH liquidity provider reward trial at the protocol level, diverting a portion of the SNX weekly inflation into a pool to incentivise liquidity providers of the sETH/ETH pair in Uniswap. The trial has been successful, but in order for this mechanism to work long term it must be formalised into the protocol.
  • SIP-12: This SIP proposes to prevent front running of the price oracle by introducing max gas price for transactions on Synthetix exchanges. Front running occurs when a user or bot reads an incoming oracle update from the mempool and transmits an exchange with higher GWEI, taking advantage of a known price movement. Front running can jeopardise the debts of SNX stakers by enabling better odds at making profitable trades, and several accounts have used front running methods already. This first phase of SIP-12 will determine a max GWEI setting based on the current Ethereum congestion (somewhere between 'standard' and 'fast'), and traders will not be able to push a trade with more GWEI than that. Synthetix.Exchange will not allow traders to use a 'fast' GWEI setting, but if someone attempts a trade using the contacts directly, if they use a higher GWEI then the transaction will fail.

Sirius (v2.10.5)

Published: Sep 26, 2019

Codebase: v2.10.5

  • SIP 16: Synthetix upgrades currently take longer than needed as the owner account makes up to 60 calls to configure the system. Most of these calls are setSynthetix and setFeePool on all of the Synths. We propose to point the Synths to the Synthetix Proxy and FeePool Proxy. This would reduce the amount of time the system is offline. Making upgrades a lot faster, cheaper (gas) and minimize the impact on users with reduced downtime.
  • SIP 17: This update will upgrade the currencyKeys from Bytes4 to Bytes32. This will enable Synthetix to create new Synths with symbols longer than 4 characters. e.g. sATOM, sDEFI, which is not currently possible with currencyKeys type defined as Bytes4.
  • SIP 18: This will recover the $2.9k sUSD that is currently unclaimable by minters in the SNX fee address. This sUSD is from the period in which there was a transfer fee for sending sUSD.
  • SIP 19: The Synthetix contracts still have transfer fees written into them, from before we disabled transfer fees in February 2018. Removing that code will optimise reclaim bytecode size required for new features.

Synthetix npm module (v2.1.9)

Published: Apr 4, 2019

Codebase: v2.1.9

We added support for synthetix as an npm module. With it, you can load the ABIs, bytecode, and target addresses for synthetix on mainnet and all available testnets (kovan, rinkeby and ropsten). Please see our documentation for more details.

10 new Synths and Synthetix upgrade (v2.1.0)

Published: Feb 26, 2019

Codebase: v2.1.0

Updates include;

  • Gas optimisation for Synth minting and burning
  • Transfer Fee Fix to allow it to be set to zero
  • SynthExchange event for DApps when exchanging between synths


Synthetix crypto-backed synthetic asset platform (v2.0.0)

Published: Dec 18, 2018

Codebase: v2.0.0

The Synthetix Platform enables the creation of on-chain synthetic assets (Synths) that track the value of assets in the real world. Some examples of assets that the platform supports now or will support in the future are synthetic fiat currencies (sUSD, sAUD, sKRW etc), synthetic commodities such as gold (sXAU), as well as more complex assets such as equity indices.


nUSD System A - Maintenance Patch 1 (v1.0.1)

Published: Aug 7, 2018

Codebase: v1.0.1

Adds some convenience functions and minor optimisations and fixes.

nUSD System A - Foundation Static Issuance (v1.0.0)

Published: Aug 7, 2018

Codebase: v1.0.0

In this version of the nUSD system, nomins are havven-backed, and only the foundation may issue, up to an issuance ratio it sets.



Ether-Backed USD Nomins (v0.1.0)

Published: Aug 7, 2018

Codebase: v0.1.0