This guide provides instructions for upgrading to specific versions of CometBFT.
This release introduces state machine-breaking changes, as well as substantial changes on the ABCI interface and indexing. It therefore requires a coordinated upgrade.
- The field
Version
in the mempool section has been removed. The priority mempool (what was called versionv1
) has been removed (see below), thus there is only one implementation of the mempool available (what was calledv0
). - Config fields
TTLDuration
andTTLNumBlocks
, which were only used by the priority mempool, have been removed.
- The priority mempool (what was referred in the code as version
v1
) has been removed. There is now only one mempool (what was called versionv0
), that is, the default implementation as a queue of transactions. - In the protobuf message
ResponseCheckTx
, fieldssender
,priority
, andmempool_error
, which were only used by the priority mempool, were removed but still kept in the message as "reserved".
- The
ABCIVersion
is now2.0.0
. - Added new ABCI methods
ExtendVote
, andVerifyVoteExtension
. Applications upgrading to v0.38.0 must implement these methods as described here - Removed methods
BeginBlock
,DeliverTx
,EndBlock
, and replaced them by methodFinalizeBlock
. Applications upgrading tov0.38.0
must refactor the logic handling the methods removed to handleFinalizeBlock
. - The Application's hash (or any data representing the Application's current state)
is known by the time
FinalizeBlock
finishes its execution. Accordingly, theapp_hash
parameter has been moved fromResponseCommit
toResponseFinalizeBlock
. - Field
signed_last_block
in structureVoteInfo
has been replaced by the more expressiveblock_id_flag
. Applications willing to keep the semantics ofsigned_last_block
can now use the following predicatevoteInfo.block_id_flag != BlockIDFlagAbsent
- For further details, please see the updated specification
This release introduces state machine-breaking changes, and therefore requires a coordinated upgrade.
When upgrading from the v0.34 release series, please note that the Go module has
now changed to github.com/cometbft/cometbft
.
- The
ABCIVersion
is now1.0.0
. - Added new ABCI methods
PrepareProposal
andProcessProposal
. For details, please see the spec. Applications upgrading to v0.37.0 must implement these methods, at the very minimum, as described here - Deduplicated
ConsensusParams
andBlockParams
. In the v0.34 branch they are defined both inabci/types.proto
andtypes/params.proto
. The definitions inabci/types.proto
have been removed. In-process applications should make sure they are not using the deleted version of those structures. - In v0.34, messages on the wire used to be length-delimited with
int64
varint values, which was inconsistent with theuint64
varint length delimiters used in the P2P layer. Both now consistently useuint64
varint length delimiters. - Added
AbciVersion
toRequestInfo
. Applications should check that CometBFT's ABCI version matches the one they expect in order to ensure compatibility. - The
SetOption
method has been removed from the ABCIClient
interface. The corresponding Protobuf types have been deprecated. - The
key
andvalue
fields in theEventAttribute
type have been changed from typebytes
tostring
. As per the Protocol Buffers updating guidelines, this should have no effect on the wire-level encoding for UTF8-encoded strings.
If you rely on the /tx_search
or /block_search
endpoints for event querying,
please note that the default behaviour of these endpoints has changed in a way
that might break your queries. The original behaviour was poorly specified,
which did not respect event boundaries.
Please see tendermint/tendermint#9712 for context on the bug that was addressed that resulted in this behaviour change.
This is the first official release of CometBFT, forked originally from Tendermint Core v0.34.24 and subsequently updated in Informal Systems' public fork of Tendermint Core for v0.34.25 and v0.34.26.
If you already make use of Tendermint Core (either the original Tendermint Core
v0.34.24, or Informal Systems' public fork), you can upgrade to CometBFT
v0.34.27 by replacing your dependency in your go.mod
file:
go mod edit -replace github.com/tendermint/tendermint=github.com/cometbft/[email protected]
We make use of the original module URL in order to minimize the impact of
switching to CometBFT. This is only possible in our v0.34 release series, and we
will be switching our module URL to github.com/cometbft/cometbft
in the next
major release.
CometBFT, by default, will consider its home directory in ~/.cometbft
from now
on instead of ~/.tendermint
.
The environment variable prefixes have now changed from TM
to CMT
. For
example, TMHOME
becomes CMTHOME
.
We have implemented a fallback check in case TMHOME
is still set and CMTHOME
is not, but you will start to see a warning message in the logs if the old
TMHOME
variable is set. This fallback check will be removed entirely in a
subsequent major release of CometBFT.
CometBFT must be compiled using Go 1.19 or higher. The use of Go 1.18 is not supported, since this version has reached end-of-life with the release of Go 1.20.
If you run into any trouble with this upgrade, please contact us.
For historical upgrading instructions for Tendermint Core v0.34.24 and earlier, please see the Tendermint Core upgrading instructions.