v5.5.0
Notable changes
RPC Changes
getdeprecationinfo
has several changes:- It now returns additional information about currently deprecated and disabled features.
- A new
end_of_service
object that contains both the block height for end-of-service and the estimated time that the end-of-service halt is expected to occur. Note that this time is just an approximation and will change over time as the end-of-service block height approaches, due to the variability in block times. Theend_of_service
object is intended to replace thedeprecationheight
field; see the Deprecations section for additional detail. - This RPC method was previously only available for mainnet nodes; it is now also available for testnet and regtest nodes, in which case it does not return end-of-service halt information (as testnet and regtest nodes do not have an end-of-service halt feature.)
- Several
z_sendmany
,z_shieldcoinbase
andz_mergetoaddress
failures have moved from synchronous to asynchronous, so while you should already be checking the async operation status, there are now more cases that may trigger failure at that stage. - The
AllowRevealedRecipients
privacy policy is now required in order to choose a transparent change address for a transaction. This will only occur when the wallet is unable to construct the transaction without selecting funds from the transparent pool, so the impact of this change is that for such transactions, the user must specifyAllowFullyTransparent
. - The
z_shieldcoinbase
RPC method now supports an optional memo. - The
z_shieldcoinbase
andz_mergetoaddress
RPC methods now support an optional privacy policy. - The
z_mergetoaddress
RPC method can now merge to UAs and can also send between different shielded pools (whenAllowRevealedAmounts
is specified). - The
estimatepriority
RPC call has been removed. - The
priority_delta
argument to theprioritisetransaction
RPC call now has no effect and must be set to a dummy value (0 or null).
Changes to Transaction Fee Selection
- The zcashd wallet now uses the conventional transaction fee calculated according to ZIP 317 by default. This conventional fee will be used unless a fee is explicitly specified in an RPC call, or for the wallet's legacy transaction creation APIs (
sendtoaddress
,sendmany
, andfundrawtransaction
) when the-paytxfee
option is set. - The
-mintxfee
and-sendfreetransactions
options have been removed. These options previously instructed the legacy transaction creation APIs to increase fees to this limit and to use a zero fee for "small" transactions that spend "old" inputs, respectively. They will now cause a warning on node startup if used.
Changes to Block Template Construction
We now use a new block template construction algorithm documented in ZIP 317.
- This algorithm no longer favours transactions that were previously considered "high priority" because they spent older inputs. The
-blockprioritysize
config option, which configured the portion of the block reserved for these transactions, has been removed and will now cause a warning if used. - The
-blockminsize
option, which configured the size of a portion of the block to be filled regardless of transaction fees or priority, has also been removed and will cause a warning if used. - A
-blockunpaidactionlimit
option has been added to control the limit on "unpaid actions" that will be accepted in a block for transactions paying less than the ZIP 317 fee. This defaults to 50.
Change to Transaction Relay Policy
The allowance for "free transactions" in mempool acceptance and relay has been removed. All transactions must pay at least the minimum relay threshold, currently100 zatoshis per 1000 bytes up to a maximum of 1000 zatoshis, in order to be accepted and relayed. (Individual nodes can change this using -minrelaytxfee
but in practice the network default needs to be adhered to.) This policy is under review and might be made stricter; if that happens then the ZIP 317 conventional fee will still be sufficient for mempool acceptance and relay.
Removal of Priority Estimation
Estimation of "priority" needed for a transaction to be included within a target number of blocks, and the associated estimatepriority
RPC call, have been removed. The format for fee_estimates.dat
has also changed to no longer save these priority estimates. It will automatically be converted to the new format which is not readable by prior versions of the software. The -txconfirmtarget
config option is now obsolete and has also been removed. It will cause a warning if used.
Deprecations
The following features have been deprecated, but remain available by default. These features may be disabled by setting -allowdeprecated=none
. 18 weeks after this release, these features will be disabled by default and the following flags to -allowdeprecated
will be required to permit their continued use:
deprecationinfo_deprecationheight
: Thedeprecationheight
field ofgetdeprecationinfo
has been deprecated and replaced by theend_of_service
object.