Reverse chronology order of release notes.

Basechain Build 1426 Hard Fork - 2021/05/24

This build makes it possible to downsize the app.db on Basechain nodes by over 700x. The downsizing works by copying out the subset of the data representing the current on-chain state to a new DB (app_v2.db). The new DB is a lot smaller than the original because a huge portion of the old app.db is taken up by data that was previously migrated to separate databases (evm.db and receipts_db). This downsizing can be triggered at a specific chain height by setting the new AppStore.CloneStateAtHeight setting in the on-chain config once all nodes are running the new build.

Any node running this build will now check whether app.db or app_v2.db contains the most recent on-chain state upon startup, if app_v2.db has the most recent state then it will be swapped with app.db like so:

  • Rename app.db -> old_app_timestamp.db
  • Rename app_v2.db -> app.db

Once the swap is complete the node will then proceed to load and use app.db as usual.

Node operators can safely delete old_app_timestamp.db to free up a whole bunch of space on their nodes.

Such a significant reduction to the size of the app.db should also help reduce the memory usage of Basechain nodes.

Upgrade instructions:

  1. Download Basechain build 1426
wget https://downloads.loomx.io/loom/linux/stable/basechain
chmod 755 basechain
  1. Restart the node on the new build.

Basechain Build 1411 Hard Fork - 2021/04/22

This build includes all the necessary parts to support LOOM transfers between Basechain and Binance Smart Chain through the BSC Transfer Gateway.

New features:

  • Update build config to support Golang 1.16.2
  • Add new bsc-gateway Go contract to handle LOOM BEP20 deposits and withdrawals on the Basechain side.
  • Add new tg:v1.7 feature flag to enable the bsc-gateway contract.

Upgrade instructions:

  1. Download Basechain build 1411
wget https://downloads.loomx.io/loom/linux/stable/basechain
chmod 755 basechain
  1. Restart the node on the new build.

Basechain Build 1385 Hard Fork - 2020/04/28

New features:

  • Disable unecessary key sorting in the EVM.
  • Add new coin allowance CLI command that can be used to check the amount of LOOM previously approved for transfer to a particular spender.
  • Add new redelegate-all CLI command that can be used to randomly redistribute delegations from former validators to active validators.
  • Extend chain-cfg list-validators CLI command to show individual validator powers. The power displayed by this command for each validator is the percentage of the validators current voting power out of the total voting power.

Upgrade instructions:

  1. Download Basechain build 1385
wget https://downloads.loomx.io/loom/linux/stable/basechain
chmod 755 basechain
  1. Restart the node on the new build.

Basechain Build 1376 Hard Fork - 2020/04/06

New features:

  • Disable SHA3 preimage recording in EVM.
  • Add new config settings to allow disabling of some unecessary key sorting in the EVM.
      EnableStateObjectDirtyStorageKeysSorting: false
      EnableTrieDatabasePreimageKeysSorting: false
    In this build this key sorting is still enabled by default, but it'll likely be disabled in the next release.
  • Disable a cache used for speeding up client queries, the caching is of no benefit to nodes that aren't queried by clients. Since the vast majority of nodes, regardless of whether or not they're validators don't respond to client queries it makes more sense to disable the caching by default. Caching can be re-enabled on nodes via the config:
      CachingEnabled: true
  • Nodes now support a new canonical_tx_hash RPC method on the /query interface that can be used to obtain a canonical tx hash from an EVM tx hash (which is just a hash of the tx receipt).
  • Add the ability to strip voting power from jailed validators while they remain jailed. This is to ensure that if a validator with a significant chunk of the voting power is offline for a long time the remaining validators can continue to swiftly reach consensus without it. Once a jailed validator is unjailed all its voting power is restored. This feature can be activated by the dpos:v3.8 feature flag.

Bug fixes:

  • Update dpos_total_staked RPC method to exclude delegations from the bootstrap nodes.
  • Update DPOS.ClaimRewardsFromAllValidators to claim rewards from all validators, previously it only claimed rewards from active validators. This fix can be enabled via the dpos:v3.6 feature flag.
  • Update default Infura URI used by the gateway withdraw-funds command, in case Infura decides to change the URI format again the default value can be overriden with the new eth-uri flag.
  • Nodes will now load the last block header on startup before responding to queries.

Upgrade instructions:

  1. Download Basechain build 1376
wget https://downloads.loomx.io/loom/linux/stable/basechain
chmod 755 basechain
  1. Restart the node on the new build.

Basechain Upgrade Part 1 of 3 - Build 1346 Hard Fork - 2019/11/27

The Basechain upgrade is the largest upgrade ever, it consists of three parts. This build is the first part, it contains improved Web3 JSON-RPC compatibility and an upgraded Binance Transfer Gateway. The second part will consist of an upgrade to the Transfer Gateway on Ethereum Mainnet, and the third and final part will address the recent rewards shortfall due to the annual 60m LOOM cap being reached sooner than expected.

Breaking changes:

  • The eth_getTransactionCount and eth_call Web3 JSON-RPC methods on the /eth endpoint now expect the input address to be an Ethereum account, not a Loom account.
  • The eth_getLogs method and any other Web3 JSON-RPC methods that query a range of blocks will now only allow querying up to 20 blocks per request on public Basechain nodes.

New features:

  • A node will now panic when it’s started using a jump-start that requires a newer build than the node is currently running. Once you upgrade the binary, you can simply restart the node without restoring the working directory from the jump-start. This requires a jump-start that’s created after the chaincfg:v1.4 feature flag is enabled, which means it will only work with future jump-starts (the first of which will be available a few days after this release).
  • The eth_sendRawTransaction JSON-RPC method on the /eth endpoint now works similarly to the way one would expect it to work on an Ethereum node. Note that an account mapping between the Ethereum account that’s used to sign the Ethereum tx and an Basechain account must exist before eth_sendRawTransaction will accept the Ethereum tx. This feature will be enabled via the tx:eth feature flag, and should unlock the ability to use any Web3 JSON-RPC compatible library to call & deploy EVM contracts via the /eth endpoint.
  • The logs returned by eth_getLogs, eth_getTransactionReceipt, and Web3 subscriptions now contain a BlockTime field. This is a Loom-specific extension of the Web3 JSON-RPC interface.
  • A new AppStore.PruneEvmKeysInterval setting has been added to the on-chain config. This will be used to tweak the pruning of ancient data.
  • Withdrawing LOOM to Binance will now incur a fee (charged in BNB). This feature will be activated by the tg:v1.4 feature flag.
  • The Binance Gateway contract will now mint & burn coin when necessary. This feature will be activated by the coin:v1.3 feature flag.
  • Nodes now support a new dpos_total_staked RPC method that returns a simple JSON-RPC response containing the total amount staked via the DPOS contract.
  • Nodes will no longer write to mempool.wal by default. This can be re-enabled in loom.yml:
    MempoolWalEnabled: true

Bug fixes:

  • Fix broadcasting of EVM contract events to subscribers. Previously, if a contract method emitted multiple events, subscribers would only receive the first event.
  • Ensure that theeth_getBlockByNumber and eth_getBlockByHash methods return the same tx hashes regardless of whether or not the full parameter is true or not.
  • Ensure eth_getLogs returns tx hashes that are consistent with eth_getBlockByNumber.
  • Transaction events will now be emitted to subscribers after the block in which the transactions are included has been committed.
  • The Binance Gateway will now adjust the decimal precision for LOOM deposits & withdrawals. This fix will be activated by the tg:v1.3 feature flag.
  • Remove redundant TokenWithdrawer field from withdrawal receipts. This fix will be activated by the tg:v1.5 feature flag.

Upgrade instructions:

  1. Download Basechain build 1346
wget https://downloads.loomx.io/loom/linux/stable/basechain
chmod 755 basechain
  1. Restart the node on the new build.

Pre-Basechain Build 1286 Hard Fork - 2019/10/01


  • Fix memory leak in the contract event subscription system.
  • Fix events being erroneously emitted by failed calls to Go contracts.
  • Store transaction receipts for failed calls to EVM contracts. Will be enabled via the receipts:v3.1 and receipts:v3.4 feature flags.
  • Stop emitting redundant jailing events once a validator is jailed.

New features:

  • eth_getStorageAt Web3 JSON-RPC method is now supported. If the block parameter is specified it must be set to latest.
  • Allow ETH to be minted on chain genesis to make it easier to test & develop payable Solidity contracts on a local node.

Upgrade instructions:

The download location and binary name have changed from the previous build, but the configuration should remain unchanged.

  1. Download Basechain build 1286
wget https://downloads.loomx.io/loom/linux/build-1286/basechain
chmod 755 basechain
  1. Restart the node on the new build.