neo-go/CHANGELOG.md

# Changelog

This document outlines major changes between releases.

## 0.99.1 "Parametrization" (28 Jul 2022)

We're updating NeoGo to push out a number of significant updates as well as
make it compatible with 3.3.1 version of C# node. The most prominent changes
are RPC sessions for iterators returned from invoke* calls, initial bits of
RPC client refactoring and support for darwin-arm64 and linux-arm64
platforms. A number of internal changes are less visible from outside, but
are also important for future evolution of the code base.

Node operators must resynchronize their nodes to get fully compatible state
(which is confirmed to be compatible with 3.3.1 for current mainnet up to
block 1932677 and T5 testnet up to block 475938). RPC client users, please
review the changes carefully and update your code wrt refactorings made as
well as iterator session support.

Subsequent releases will also change RPC client and associated code, we want
to make it easier to use as well as extend its functionality (see #2597 for
details, comments and suggestions are welcome). 0.99.2 is expected to be
released somewhere in August with 3.4.0 C# node compatibility.

New features:
 * `getcandidates` RPC method to get full list of registered candidates and
   their voting status (#2587)
 * wallet configuration file support to simplify using CLI non-interactively,
   use `--wallet-config` option instead of `--wallet` if needed (#2559)
 * session-based JSON-RPC iterator API for both server and client with
   `traverseiterator` and `terminatesession` calls; notice that the default
   server behavior (`SessionEnabled: false`) is compatible with NeoGo 0.99.0,
   iterators are expanded the way they were previously, only when sessions are
   enabled they're returned by the server to the client (#2555)
 * `interop` package now provides helper methods for proper `Hash160`,
   `Hash256` and other type comparisons in smart contracts (#2591)
 * `smartcontract.Builder` type to assist with entry script creation as well
   as a set of CreateXXXScript functions for simple cases (#2610)

Behavior changes:
 * 3.3.1-compatible order of ABI methods for the native NeoToken contract
   which affects LedgerContract state (#2539)
 * `getnextvalidators` RPC was reworked to be compatible with C# node, if you
   rely on Active flag from the old response or full candidate list please use
   `getcandidates` method (#2587)
 * `--account` parameter for `contract manifest add-group` CLI command was
   changed to `--address` (short `-a` is still the same) for better
   consistency with other commands (#2559)
 * (*WSClient).GetError won't return an error in case the connection was
   closed with (*WSClient).Close
 * `getnepXXbalances` RPCs now return decimals, symbol and token name data
   along with asset hash (#2581)
 * Ledger.GetBlock will now return state root hash for chains that use
   StateRootInHeader extension (#2583)
 * `request.RawParams` type is gone (but it likely wasn't used anway), if
   needed use `[]interface{}` directly (#2585)
 * `RawParams` field of `request.Raw` was renamed to `Params` (#2585)
 * `vm.State` type moved to a package of its own (`vm/vmstate`) to avoid
   importing whole VM where only State type is needed (#2586)
 * `MaxStorageKeyLen` and `MaxStorageKeyLen` definitions moved from
   `core/storage` to `config/limits` package simplifying their usage (#2586)
 * `vm.InvocationTree` type moved into `vm/invocations` (#2586)
 * `storage.Operation` type moved into `storage/dboper` package (#2586)
 * `rpc/server` package moved to `services/rpcsrv` (#2609)
 * `rpc/client` package moved to `rpcclient` (#2609)
 * `network/metrics` package moved to `services/metrics` (#2609)
 * `rpc/request` and `rpc/response` packages were merged under `neorpc`,
   `request.Raw` is `neorpc.Request` now, while `response.Raw` is
   `neorpc.Response` (#2609)
 * `rpc.Config` type was moved to `config.RPC` (#2609)
 * `subscriptions.NotificationEvent` type moved to
   `state.ContainedNotificationEvent` (#2609)
 * `subscriptions.NotaryRequestEvent` type moved to
   `result.NotaryRequestEvent` (#2609)

Improvements:
 * new `make` targets to build NeoGo binaries locally or using Docker
   environment (#2537, #2541)
 * more detailed client-side error on JSON-RPC WebSocket connection closure
   (#2540)
 * various node's micro-optimizations both for CPU usage and memory
   allocations (#2543)
 * new Wallet method that allows to save it in pretty format (#2549)
 * massive test code refactoring along with some core packages restructuring
   (#2548)
 * transaction package fuzz-test (#2553)
 * simplified client-side Error structure, more predefined errors for
   comparisons, refactored server side of RPC error handling (#2544)
 * more effective entry scripts for parameterless function invocations via RPC
   (#2558)
 * internal services now can start/stop properly independent of other node
   functionality (#2566, #2580)
 * all configurations now use 'localhost' instead of 127.0.0.1 (#2577)
 * documented JSON behavior for enumerations which deviates from C# node
   slightly (#2579)
 * better error messages in the CLI for invocations (#2574)
 * compiler can inline methods now (#2583)
 * `interface{}()` conversions are supported by the compiler now (although
   they don't change values, #2583)
 * server-side code moved out of common RPC packages completely (#2585, #2586)
 * metrics and DB configurations moved to config and dbconfig packages (#2586)
 * calling methods on returned values is now possible in Go smart contracts
   (#2593)
 * NNS contract now cleans up old entries in case a domain is registered again
   after expiration (#2599)
 * GetMPTData P2P messages (from P2PStateExchangeExtensions) can now be
   processed even if KeepOnlyLatestState is enabled (#2600)
 * builds and regular tests for MacOS (#2602, #2608)
 * internal `blockchainer.Blockchainer` is finally gone, simplifying some
   dependencies (#2609)
 * updated CLI `--version` output format to conform with NeoFS tooling style
   (#2614)

Bugs fixed:
 * dBFT update: increase the number of nodes that respond to RecoveryRequest
   (#2546, nspcc-dev/dbft#59)
 * invalid block height estimation for historic calls (#2556)
 * Signature parameter to RPC invocations was expected in hex format instead
   of base64 (#2558)
 * missing data in RPC server error logs in some cases (#2560)
 * potential deadlock in consensus node before the dBFT process is started
   (#2567)
 * dBFT update: ChangeView messages were not correctly transmitted in
   RecoveryResponse messages (#2569, nspcc-dev/dbft#60)
 * dBFT update: ChangeView messages from newer views were not correctly
   processed by outdated node (#2573, nspcc-dev/dbft#61)
 * RPC server restarts via SIGHUP could lead to server not starting at all in
   very rare case (#2582)
 * inlined code couldn't have multiple `return` statements (#2594)
 * empty list of transactions is now returned instead of `null` in `getblock`
   RPC responses when block doesn't contain transactions, the same way C# node
   does (#2607)
 * candidate registration didn't invalidate committee cache leading to state
   differences for T5 testnet (#2615)

## 0.99.0 "Overextrapolation" (03 Jun 2022)

A big NeoGo upgrade that is made to be compatible with C# node version
3.3.0. All of the protocol changes are implemented there with the main one
being the Aspidochelone hardfork that will happen on mainnet
soon. Compatibility is confirmed for current T5 testnet and mainnet, but this
version requires a resynchronization so schedule your updates accordingly.

But it's not just about the protocol changes, this release introduces an
ability to perform historic invocations via RPC for nodes that store old MPT
data. Using `invokefunctionhistoric` you can perform some invocation with the
chain state at the given height, retreiving old balances, ownership data or
anything else you might be interested in.

Please also pay attention to configuration files used by your node, mainnet
ones must have Aspidochelone hardfork enabled at height 1730000 to be
compatible and T5 testnet enables it at height 210000. T5 testnet is different
from T4, it uses different magic number, different seed nodes and different
protocol configuration settings. 0.99.0 won't work for T4 testnet, please
use 0.98.5 for it.

New features:
 * new methods in native contracts:
   - getTransactionVMState and getTransactionSigners in LedgerContract (#2417,
     #2447, #2511)
   - murmur32 in CryptoLib (#2417)
   - getAllCandidates and getCandidateVote in NeoToken (#2465)
 * System.Runtime.GetAddressVersion syscall (#2443)
 * StartWhenSynchronized option for RPC server (defaults to the old behaviour,
   #2445)
 * historic RPC invocations (invokefunctionhistoric, invokescripthistoric and
   invokecontractverifyhistoric APIs, #2431)
 * protocol hardforks, with Aspidochelone being the first supported (#2469,
   #2519, #2530, #2535)
 * MODMUL and MODPOW VM instructions (#2474)
 * ability to get connection closure error from WSClient (#2510)
 * isolated contract calls with state rollback on exception (#2508)
 * vote and candidate state change events in the NEO contract (#2523)
 * immutable compound types in VM (#2525)

Behavior changes:
 * ContractManagement deploy and update methods now require AllowCall flag
   (#2402)
 * GetStorageItems* APIs are no longer available in dao package, use Seek*
   (#2414)
 * committee candidates are now checked against the Policy contract block list
   (#2453)
 * getCandidates NEO method returns no more than 256 results now (#2465)
 * EQUAL checks are limited to 64K of data in VM now irrespective of the
   number of elements compared (#2467)
 * Create[Standard/Multisig]Account prices were raised to avoid DoS attacks
   (#2469)
 * System.Runtime.GetNotifications syscall costs 16 times more GAS now (#2513)
 * System.Runtime.GetRandom syscall now costs more and uses more secure seed
   (#2519)

Improvements:
 * better messages for some CLI commands (#2411, #2405, #2455)
 * fixes and extensions for example contracts (#2408)
 * better neotest documentation (#2408)
 * internal tests now use neotest framework more extensively (#2393)
 * neotest can now be used for benchmark code and has more multi-validator
   chain methods (#2393)
 * big (>64 bit) integers can now be used for RPC calls (#2413)
 * no error is logged now when notary-assisted transaction is already in the
   mempool (it's not an error, #2426)
 * T5 testnet with more aggressive protocol parameters (#2457)
 * destroyed contracts are blocked now (#2462)
 * JSONization errors for invoke* RPCs are now returned in exception field of
   the answer (#2461)
 * typos, grammar and spelling fixes in documentation, comments and messages
   (#2441, #2442)
 * faster RPC client initialization (#2468)
 * RPC processing errors use ERROR log severity now only if there is a
   server-side error occurred (2484)
 * increased server-side websocket message limit to fit any request (#2507)
 * invalid PrepareRequest now doesn't require other nodes to be alive to send
   ChangeView (#2512)
 * updated YAML library dependency (#2527)
 * notary subsystem compatibility fixes, using new IDs and options (#2380)
 * minor performance improvements (#2531)

Bugs fixed:
 * websocket-based RPCs were not counted in Prometheus metrics (#2404)
 * input data escaping missing for RPC log messages (#2404)
 * compiler panic in notification checking code (#2408)
 * missing 'hash' field in the debug data (#2427)
 * debug data used relative paths that are not compatible with neo-debugger
   (#2427)
 * getversion RPC method wasn't compatible with C# implementation (#2435,
   #2448)
 * old BaseExecFee and StoragePrice values could be used by transactions in
   the same block with transactions that change any of them (#2432)
 * context initialization race in dbft (#2439)
 * some stateroot data functions used incorrect keys in the DB (#2446)
 * voter reward data could not be deleted in NEO contract in some cases
   (#2454)
 * the maximum number of HTTPS oracle redirections is limited to 2 (and only
   using HTTPS) for C# compatibility (#2456, #2389)
 * maximum number of contract updates wasn't limited leading to overflow (#2462)
 * incorrect interop signature for getCandidates NEO contract method (#2465)
 * next instruction validitiy check is performed now before instruction
   pointer move to be compatible with C# implementation (#2475)
 * concurrent map access in Seek leading to panic (#2495, #2499)
 * insecure password reads (#2480)
 * minor VM reference counting fixes (#2498, #2502, #2525)
 * panic during serialization of transaction with empty script (#2485)
 * 'exception' field was missing in the invoke* RPC call output when there is
   no exception which differed from C# node behaviour (#2514)
 * interop interfaces used incompatible (wrt C# node) type string in JSON
   (#2515)
 * minor genesis block state differences wrt C# implementation (#2532)
 * incompatible (wrt C#) method offset check (#2532)

## 0.98.5 "Neutralization" (13 May 2022)

An urgent update to fix the same security issue that was fixed in 3.1.0.1 C#
node release. Please upgrade as soon as possible, resynchronization is not
needed for mainnet.

Bugs fixed:
 * GAS emission now happens after NEO transfer is finished (#2488)

## 0.98.4 "Mesmerization" (11 May 2022)

An urgent release to fix incompatibility with mainnet at block 1528989. The
actual pair of problems leading to inability to process this block occurred
earilier than that, so to fix this you need to resynchronize your node. Fixed
node is confirmed to have identical state as 3.1.0 C# node up to block
1529810.

Bugs fixed:
 * StdLib itoa() implementation emitted uppercase letters instead of lowercase
   (#2478)
 * StdLib jsonDeserialize() implementation couldn't handle properly integers
   larger than 64-bit signed (#2478)

## 0.98.3 "Liquidation" (07 May 2022)

This is a hotfix release to fix t4 testnet incompatibility at block
1589202. The actual problem was found and fixed during 0.99.0 development
cycle, but 0.99.0 is expected to be incompatible with t4 testnet. This release
allows to continue working with it as well as mainnet (and contains some other
fixes for known problems). It does not require resynchronizing a node.

Improvements:
 * double call to `WSClient.Close()` method won't cause a panic (#2420)

Bugs fixed:
 * Rules scope considered as invalid in binary representation (#2452)
 * incorrect compressed P2P message could lead to panic (#2409)
 * notary-assisted transaction could be in inconsistent state on the Notary
   node (#2424)
 * WSClient panics if request is made after connection breakage (#2450)
 * Rules scope JSON representation wasn't compatible with C# implementation
   (#2466)
 * JSONized Rules scope could only contain 15 conditions instead of 16 (#2466)

## 0.98.2 "Karstification" (21 Mar 2022)

We've decided to release one more 3.1.0-compatible version bringing all of the
new features and bug fixes (along with complete support for Windows platform)
made before going into full 3.2.0 compatibility. It's important for us to give
you more stable and flexible environment for the ongoing hackathon. Contract
bindings generator might be very useful for anyone operating with already
deployed contracts written in other languages, while the node itself can now
be configured for lightweight operation, keeping only the data relevant for
the past MaxTraceableBlocks, no more and no less. Current public networks
don't benefit from it yet with their large MaxTraceableBlocks setting, but
they're growing every day and it's just a matter of time when this feature
will start making a difference. And sorry, but this release is again faster
than the previous one.

We recommend updating, but if your node is not public and you don't
specifically want to play with new things brought by it you might as well wait
for the next one. It requires resynchronization and 0.99.0 will do too because
of planned protocol changes.

New features:
 * protocol extension allowing to change the number of validators in existing
   network (#2334)
 * MPT garbage collection mechanism allowing to store a set of latest MPTs,
   RemoveUntraceableBlocks setting now activates it by default unless
   KeepOnlyLatestState is used (#2354, #2360)
 * NEP-11/NEP-17 transfer data garbage collection (#2363)
 * Go bindings generator based on contract manifests (#2349, #2359)

Behavior changes:
 * some RPC client functions for divisible NEP-11 changed signatures using
   slice of bytes now instead of strings for IDs (#2351)
 * heavily refactored storage and dao package interfaces (#2364, #2366)
 * support for Go 1.18 added, 1.15 dropped (#2369)

Improvements:
 * additional CLI tests (#2341)
 * `defer` statement is now compiled more effectively (#2345)
 * `defer` statement can be used in conditional branches now (#2348)
 * new tests for divisible NEP-11 contract (#2351)
 * all tests failing on Windows platform are fixed (#2353)
 * RPC functions now accept integers larger than 2^64 from strings (#2356)
 * 10-35%% improvement in bulk block processing speed (node synchronization)
   depending on machine and configuration (#2364)
 * reworked VM CLI fixing Windows incompatibility and UTF-8 bugs (#2365)
 * incompletely signed transaction JSONs now also contain hash (#2368)
 * RPC clients can now safely be used from multiple threads (#2367)
 * additional tests for node startup sequences (#2370)
 * customizable notary service fee for Notary extension (#2378)
 * signers passed into RPC methods can now contain rules (#2384)
 * compiler tests now take less time (#2382)
 * some fuzzing tests added (#2399)

Bugs fixed:
 * test execution result wasn't checked for CLI invocations that saved
   transaction into file (#2341)
 * exception stack wasn't properly cleared during CALL processing in VM (#2348)
 * incorrect contract used in RPC client's GetOraclePrice (#2378)
 * oracle service could be tricked by redirects into going to local hosts when
   this was disabled (#2383)
 * `invoke*` RPC functions could be used to trigger OOM with specially crafted
   scripts (#2386)
 * some edge-cased integer conversions were not exactly matching the behavior
   of C# node in VM (#2391)
 * HASKEY instruction wasn't working for byte arrays (#2391)
 * specially-crafterd JSONPath filters for oracle requests could trigger OOM
   (#2372)
 * ENDFINALLY opcode before ENDTRY could lead to VM panic (#2396)
 * IsScriptCorrect function could panic on specially-crafted inputs (#2397)

## 0.98.1 "Immunization" (31 Jan 2022)

Bug fixes, interesting optimizations, divisible NEP-11 example and a big
compiler update --- everything you wanted to find in this NeoGo update. It
requires chain resynchronization, but this resynchronization will be faster
than ever.

One thing should also be noted, even though this release is 3.1.0-compatible,
it is known to have a different state for testnet after block 975644, but it's
not a NeoGo fault, it'll be fixed in the next C# node release. The root cause
is well-known and is not considered to be critical compatibility-wise.

New features:
 * support for reading the wallet from stdin in CLI (where it's possible, #2304)
 * new CLI command for wallet password change (#2327)
 * `getstateroot` support in RPC client (#2328)
 * divisible NEP-11 example (#2333)
 * helper script to compare node states via RPC (#2339)

Behavior changes:
 * zero balance is explicitly printed now for token-specific NEP-17 balance
   requests from CLI (#2315)
 * pkg/interop (used by smart contracts) is a separate Go module now (#2292,
   #2338)
 * smart contracts must be proper Go packages now (#2292, #2326)

Improvements:
 * optimized application log storage (#2305)
 * additional APIs in `neotest` framework (#2298, #2299)
 * CALLT instruction is now used by the compiler where appropriate leading to
   more optimized code (#2306)
 * DB seek improvements increasing chain processing speed by ~27% (#2316, #2330)
 * updated NeoFS dependencies (#2324)
 * optimized emitting zero-length arrays in `emit` package used to construct
   scripts (#2299)
 * native contract tests refactored using generic contract testing framework (#2299)
 * refactored internal Blockchainer interfaces, eliminating unnecessary
   dependencies and standardizing internal service behavior (#2323)
 * consensus process now always receives incoming transactions which might be
   helpful for accepting conflicting (wrt local pool) transactions or when the
   memory pool is full (#2323)
 * eliminated queued block networked re-requests (#2329)
 * better error reporting and parameter handling in FindStates RPC client
   method (#2328)
 * invoke* RPCs now also return notifications generated during execution (#2331)
 * it's possible to get storage changes from the result of invoke* RPCs (#2331)
 * better transfer data storage scheme resulting in faster getnep* RPC
   processing (#2330)
 * dropped deprecated `loader` package from compiler dependencies moving to
   updated x/tools interface (#2292)

Bugs fixed:
 * incorrect handling of missing user response in CLI (#2308)
 * improper primary node GAS distribution in notary-enabled networks (#2311)
 * excessive trailing spaces in the VM CLI output (#2314)
 * difference in JSON escaping wrt C# node leading to state difference for
   testnet at block 864762 (#2321)
 * potential panic during node shutdown in the middle of state jump (#2325)
 * wrong parameters for `findstates` call in RPC client (#2328)
 * improper call flags in Notary contract `withdraw` method (#2332)
 * incorrect ownerOf signature for divisible NEP-11 contracts (#2333)
 * missing safeness check for overloaded methods in the compiler (#2333)

## 0.98.0 "Zincification" (03 Dec 2021)

We've implemented all of Neo 3.1.0 protocol changes in this release (and
features like NEP-11 transfer tracker), but as usual it's not the only thing
it contains. If you're developing contracts in Go you might be interested in
contract testing framework this release brings with it, which allows you to
write automated tests in Go. You can also build a node for Windows now and
most of functionality works there (but some known problems still exist, so
this port is considered to be experimental for now). As usual there were some
optimizations made in various components as well as bug fixes.

There are also some things removed in this release, that is BadgerDB and
RedisDB support, this will allow us to optimize better for LevelDB and BoltDB
in future. Notice also that this release requires full node resynchronization.

New features:
 * optional signer scope parameter for deploy command (#2213)
 * interop packages extended with Abort() function and useful constants (#2228)
 * notary subsystem now allows to have multiple multisignature signers as well
   as combining simple notary-completed accounts with multisignature ones (#2225)
 * configurable method overloading for the compiler (#2217)
 * initial support for the Windows platform (#2239, #2265, #2267, #2264,
   #2283, #2288)
 * contract testing framework (#2229, #2262)
 * `Rules` witness scope (#2251)
 * PACKMAP/PACKSTRUCT opcodes and UNPACK extension (#2252)
 * NEP-11 transfer tracking with RPC API (#2266)
 * support for structure field slicing in the compiler (#2280)
 * invoked contract tracing for invoke* RPCs (#2270, #2291)

Behavior changes:
 * BadgerDB and RedisDB are no longer available for DB backend (#2196)
 * GetNEP17Transfers() RPC client method now works with Uint160 parameter
   instead of address (#2266)

Improvements:
 * compiler optimizations (#2205, #2230, #2232, #2252, #2256)
 * output fees as proper decimals in the CLI (#2214)
 * private network created from Makefile now uses dynamic IP addresses (#2224)
 * various minor optimizations across whole codebase (#2193, #2243, #2287, #2290)
 * `util convert` command now also handles base64 representations of script
   hashes (#2237)
 * unified "unknown transaction" RPC responses (#2247)
 * faster state switch when using P2P state synchronization extension (#2201)
 * better logging for oracle errors (#2275)
 * updated NeoFS client library dependency (#2276)

Bugs fixed:
 * getproof RPC API didn't handle destroyed contracts correctly (#2215)
 * invokefunction RPC returned error if no parameters were passed (#2220)
 * incorrect handling of empty MPT batch (#2235)
 * incoming block queue using more memory than it should, up to OOM condition
   on stuck node (#2238)
 * panic on peer disconnection in rare cases (#2240)
 * panic on password read failure (#2244)
 * miscompiled functions using `defer` and returning no values (#2255)
 * oracle responses processed not using request witnesses (#2261)
 * CreateTxFromScript() RPC client method incorrectly handled CustomContracts
   and CreateTxFromScript sender scopes (#2272)
 * potential OOM during synchronization on systems with slow disks (#2271)
 * incorrect oracle peer configuration in the default private network (#2278)
 * compiler error processing functions using defer and inlined calls (#2282)
 * node that is simultaneously a CN and Oracle node could create invalid
   oracle response transactions (#2279)
 * incorrect GetInvocationCounter() result in some cases (#2270)

## 0.97.3 "Exception" (13 Oct 2021)

This updated version of NeoGo is made to be compatible with Neo 3.0.3 bringing
with it all corresponding protocol changes and bug fixes so that you can use
it on public testnet and mainnet. It also brings with it a complete
experimental P2P state exchange extension for private networks as well as
additional optimizations. This is the first version requiring at least Go 1.15
to compile, so make sure your Go is up to date if you're not using pre-built
binaries. Protocol updates and bug fixes made in this release require a
resynchronization on upgrade.

We also make a final call on Badger and Redis DB issue #2130, if there are no
active users of them, support for both will be removed in the next release.

New features:
 * MaxConnsPerHost RPC client option (#2151)
 * P2P state exchange extension (#2019)
 * transaction-related CLI commands now show calculated fees before
   sending transaction to RPC node and ask for confirmation (#2180)
 * test invocations are now possible for partially-signed transactions stored
   in JSON format (used for manual signing by multiple parties, #2179)
 * `getstate` and `findstates` RPC to retrieve historic state data (#2207)

Behavior changes:
 * added support for Go 1.17, dropped Go 1.14 (#2135, #2147)
 * blocking native contracts is no longer possible in Policy contract (#2155)
 * `getversion` RPC call now also returns protocol configuration data (#2161,
   #2202)
 * NEF files now have Source field that can be specified in contract's
   metadata (#2191)
 * notification events from contracts in subscription service now also contain
   container (transaction usually) hash (#2192)
 * out of bounds exceptions can be catched in contracts now for PICKITEM and
   SETITEM VM instructions (#2209)

Improvements:
 * reduced number of memory allocations in some places (#2136, #2141)
 * VM optimizations (#2140, #2148)
 * notary subsystem documentation (#2139)
 * documentation fixes (#2162)
 * VM CLI now allows to dump slots (#2164)
 * better IPv6 checks in example NNS contract and `getAllRecords` method (#2166)
 * updated linters (#2177)
 * Migrate methods renamed into Update in examples (#2183)
 * old (no longer available) interop function names removed (#2185)
 * optimized processing of voting NEO transfers (#2186)
 * configuration parameters specified in seconds no longer use (improper)
   time.Duration type (#2194)
 * better error message for conflicting transactions (#2199)
 * open wallet in read-only mode if not changing it (#2184)
 * optimized header requests in P2P communication (#2200)
 * compiler now checks for method existence if it's specified as safe in
   metadata (#2206)

Bugs fixed:
 * incorrect CustomGroups witness scope check (#2142)
 * empty leaf values were ignored for MPT calculcations (#2143)
 * lower-case hexadecimal in block header JSON output (differing from C# node,
   #2165)
 * `getblockheader` RPC result missing `Nonce` and `Primary` fields (#2165)
 * return empty list of unverified transactions for `getrawmempool` RPC
   instead of null (C# node never returns null, #2165)
 * return empty list of NEF tokens in JSON format instead of null which C#
   node never returns (#2165)
 * races in some tests (#2173)
 * parameter context JSON serialization/deserialization incompatiblity with C#
   node leading to interoperability problems (#2171)
 * transfers of 0 GAS or NEO were not possible (#2169)
 * incorrect ContentTypeNotSupported oracle response transaction handling (#2178)
 * JSON escaping differences with C# implementation (#2174)
 * NEO balance update didn't save LastUpdatedBlock before GAS distribution
   leading to problems in transactions with recursive NEO transfers (#2181)
 * panic in CLI transfer command when missing destination address (#2211)
 * multiple blank identifiers in function/method were misinterpreted by the
   compiler (#2204)
 * `getnep17transfers` used uint32 for internal time processing which is not
   enough for ms-precision N3 timestamps (#2212)
 * PICKITEM instruction could fail on attempt to get an item with long key
   from map (#2209)

## 0.97.2 "Dissipation" (18 Aug 2021)

We're rolling out an update for NeoGo nodes that mostly concentrates on
performance. We've tweaked and tuned a lot of code while staying compatible
with N3 mainnet and testnet. At the same time we're gradually introducing
changes required for our P2P state exchange extension and this affected DB
format, so you'll need to resynchronize on update. This update is not
mandatory though, 0.97.1 is still perfectly valid for N3 networks.

Note also that we're discussing removal of Badger and Redis databases support
in future releases, so if you're interested in them take a look at #2130.

Behavior changes:
 * address blocking in Policy contract now also blocks calls to contracts with
   blocked addresses (#2132)

Improvements:
 * numerous memory and CPU optimizations across whole codebase (#2108, #2112,
   #2117, #2118, #2122, #2123, #2128, #2114, #2133)
 * preliminary work for P2P state exchange extension (#2119)
 * `util convert` command now also detects public keys and converts them to
   script hash/address (#2125)

Bugs fixed:
 * key decoding functions could accept some additional data even though only
   key is expected to be present (#2125)
 * conflicting dummy transactions could stay in the DB even with block removal
   enabled (#2134)

## 0.97.1 "Gasification" (06 Aug 2021)

We're updating NeoGo to make it compatible with the latest protocol changes
made in 3.0.2 version of C# node. But that's not the only thing we do, this
release also fixes one important bug, improves node's performance and adds CLI
support to add group signatures to manifests.

It requires resynchronization on upgrade.

New features:
 * `contract manifest add-group` command to add group signatures to contract
   manifest (#2100)

Behavior changes:
 * GAS contract no longer has Refuel method, it could be used as DOS
   amplification tool for attacks on network and there is no way to securely
   fix it (#2111)

Improvements:
 * memory store optimizations leading to substantial single-node TPS
   improvements (#2102)
 * various micro-optimizations across the board both for CPU usage and memory
   allocations (#2106, #2113)
 * optimized transaction decoding (#2110)

Bugs fixed:
 * ping messages created with wrong value used for node's height (#2115)

## 0.97.0 "Ventilation" (02 Aug 2021)

This is an official 3.0.0-compatible release that is ready to be used both for
mainnet and testnet. Technically, 0.96.0 and 0.96.1 are compatible too, but
they need an updated configuration to work on mainnet while this version has
it covered.

We keep improving our node and this release is not just a repackage of
something older, so DB format changes require a resynchronization if you're
upgrading from 0.96.X.

Behavior changes:
 * updated configuration for mainnet (#2103)

Improvements:
 * documentation for contract configuration file (#2097)
 * significant change to NEP-17 tracking code, it shouldn't affect valid
   NEP-17 tokens, but now we store a little less data in the DB and get more
   from token contracts when needed (for `getnep17balances` RPC for
   example); this change is required for our future state exchange protocol
   extension (#2093)
 * improved block processing speed on multicore systems (#2101)
 * JSON deserialization now has the same limits as binary, but this doesn't
   affect any valid code (#2105)

Bugs fixed:
 * potential deadlocks in notary-enabled nodes (#2064)
 * wallet files not truncated properly on key removal (#2099)

## 0.96.1 "Brecciation" (23 Jul 2021)

New CLI commands, updated dependencies and some bugs fixed --- you can find
all of this in the new NeoGo release. It's compatible with 0.96.0 (except for
multisignature contexts, but you're not likely to be using them) and
confirmed to have proper RC4 testnet state up to 15K blocks (but 0.96.0 is
fine wrt this too). At the same time we recommend to resynchronize the chain
if you're using LevelDB or BoltDB, both databases were updated.

New features:
 * `query candidates`, `query committee` and `query height` CLI commands
   (#2090)
 * `GetStateHeight` RPC client call support (#2090)

Behavior changes:
 * `wallet candidate getstate` command was renamed to `query voter`, now it
   also prints the key voted for and handles addresses with 0 balance without
   spitting errors (#2090)

Improvements:
 * `query tx` now outputs signer address along with script hash (#2082)
 * updated many of node's dependencies including BoltDB and LevelDB, there are
   no radical changes there, mostly just some fixes improving stability (#2087)
 * better error messages in some places (#2089, #2091)

Bugs fixed:
 * `query tx` command wasn't providing correct results if used with C# RPC
   node (#2082)
 * watch-only node (with a key, but not elected to participating in consensus)
   could panic on receiving a number of Commit messages (#2083)
 * `getstateheight` RPC call produced result in different format from C# node
   (#2090)
 * JSON representation of multisignature signing context wasn't compatible
   with C# implementation (#2092)

## 0.96.0 "Aspiration" (21 Jul 2021)

We're updating NeoGo to support RC4 changes, there are some incompatible ones
so this version can't be used with RC3 networks/chains (RC3 testnet is
still available, please use 0.95.4 for it). This release was checked for RC4
testnet compatibility and has the same state as C# for the first 5K blocks.

No significant protocol changes are expected now as we're moving to final N3
release, but we'll keep updating the node fixing bugs (if any), improving
performance and introducing NeoGo-specific features.

New features:
 * "System.Runtime.GetNetwork" system call (#2043)
 * ContentTypeNotSupported oracle return code and content type configuration
   for Oracle service (#2042)
 * block header have "Nonce" field again which is used for
   "System.Runtime.GetRandom" system call (#2066)
 * import from incremental chain dumps (#2061)
 * configurable initial (from the genesis block) GAS supply (#2078)
 * "query tx" CLI command to check for transaction status (#2070)

Behavior changes:
 * verification GAS limits were increased (#2055)
 * SQRT price reduced (#2071)
 * binary deserialization is now limited to 2048 (MaxStackSize) items (#2071)
 * notary deposit is stored now as serialized stack item (#2071)
 * testnet and mainnet configuration updates (#2077, #2079, #2081)

Improvements:
 * faster stack item binary and JSON serialization (#2053)
 * faster Storage.Find operation (#2057)
 * additional documentation for public network CNs (#2068)
 * better code reuse for native contract's data serialization (#2071, see new
   stackitem.Convertible interface)
 * some types from state package renamed to remove "State" word (#2075)
 * util.ArrayReverse helper moved to package of its own with additional
   helpers (#2075)

Bugs fixed:
 * nested structure cloning could lead to OOM (#2054, #2071)
 * addresses were not accepted for witness accounts in RPC calls (#2072)
 * POW instruction could take unknown amount of time to complete for big
   parameters (#2060)
 * oracle contract could accept invalid user data (#2071)
 * EQUAL for deeply nested structures could never complete (#2071)
 * arrays and structures were limited to 1024 items (#2071)
 * oracle fallback transactions could try using outdated ValidUntilBlock value
   (#2074)
 * oracle node starting from genesis block tried to process all requests from
   the chain instead of only working with current ones (#2074)
 * some tests used non-unique/wrong temporary files and directories (#2076)

## 0.95.4 "Yatter" (09 Jul 2021)

Making a fully compliant Neo node is not easy, there are lots of minuscule
details that could be done in a little different way where both ways are
technically correct but at the same time just different which is enough to
create some interoperability problems. We've seen that with Legacy node
implementation where we were functionally complete with 0.74.0 release but
some fixes kept coming up to the most recent 0.78.3 version. It was a bit
easier with Legacy because we already had some years-long chains to test the
node against while N3 is a completely new territory.

So we'd like to thank all RC3 hackathon participants as well as all other
people playing with N3 RC3 network, your joint efforts gave enough material
to keep us busy fixing things for some time. The chain moving forward hit more
and more edge cases with every block and this is actually very helpful, we saw
a lot of things that could be improved in our node and we improved them.

Now we're releasing 0.95.4 with all of these fixes which is still
RC3-compatible and it's stateroot-compatible with C# implementation up to 281K
blocks. Please resynchronize to get identic testnet state. And most likely
that's the last RC3-compatible release as we're moving forward to the official
3.0.0 release of C# version NeoGo will be updated with appropriate changes
(some of which are not compatible with RC3).

New features:
 * 'sysgas' parameter for invocation and transfer CLI commands to manually add
   some system fee GAS (#2033)

Behavior changes:
 * contract calls are now checked against specified permissions by the
   compiler (#2025)
 * stack items with nesting levels of 10 and more won't be serialized to JSON
   for purposes like including them into RPC call reply (#2045)

Improvements:
 * AddHeaders() with multiple headers added at the same time now works with
   StateRootInHeader option (#2028)
 * cached GAS per vote value leads to substantially improved block processing
   speed (#2032)
 * failed native NEP-17 transfers now still re-save the old value to the
   storage making state dumps compatible with C# (#2034)
 * refactored and renamed some stackitem package functions, added proper error
   values in all cases (#2045)
 * RPC calls (and application logs) can now return real serialization errors
   if there are any (previously all errors were reported as "recursive
   reference", #2045)
 * better tests (#2039, #2050)

Bugs fixed:
 * wrong onNEP11Payment name in contract configuration examples (#2023)
 * missing permission sections in contract configuration examples (#2023)
 * buffer stack item deserialization created byte string (#2026)
 * Extra contract manifest field serialization was reworked to match C#
   implementation more closely (#2021)
 * wildcard permission in manifest allowed any methods, while it shouldn't
   (#2030)
 * group permission in manifest worked incorrectly for a set of groups (#2030)
 * call flags were JSONized in incompatible way (#2041)
 * MPT update left branch nodes with 1 child in some cases (#2034, #2047)
 * JSON marshalling code for stack items detected item recursion in some cases
   where no actual recursion was present (#2045)
 * binary serialization code for stack items could overwrite old errors in
   some cases (#2045)
 * binary serialization code for stack items wasn't ensuring maximum size
   limit during serialization which could lead to OOM (#2045)
 * batched MPT update create excessive extension nodes for the last child of
   branch node in some cases (#2047)
 * in some cases "TCP accept error" was logged during node shutdown (#2050)
 * contract updating code was updating caches before they should've been
   updated (#2050)
 * INVERT/ABS/NEGATE unary operations were not copying their arguments (#2052)

## 0.95.3 "Yuppification" (17 Jun 2021)

One more N3 RC3-compatible release that fixes testnet state difference at
block 151376. Please resynchronize to get proper testnet state.

Behavior changes:
 * NEP2-related functions in `crypto/keys` package changed a bit to allow
   Scrypt parameters overriding, standard parameters are available via
   `NEP2ScryptParams` function (#2001)

Improvements:
 * better unit test stability (#2011, #2001)
 * updated neofs-api-go dependency (with support for TLS-enabled NeoFS node
   connections, #2003)
 * removed annoying token matching warning (#2018)

Bugs fixed:
 * state mismatch resulting from different committee candidate sorting (#2017)

## 0.95.2 "Echolocation" (10 Jun 2021)

This is another N3 RC3-compatible release and it's better in its RC3
compatiblity than the previous one because we've fixed some state mismatches
wrt C# implementation that were found on testnet. It is confirmed to have the
same state up to 126K height (which is current), but to get proper state you
need to resynchronize your node from the genesis.

New features:
 * RPC notification subsystem was extended to support notary pool events, so
   clients can now react on request additions (#1984)
 * compiler now checks notification event name length to fit into the limit
   (#1989)
 * compiler now also checks for runtime.Notify() calls from Verify method
   (which won't work anyway, #1995)

Improvements:
 * codegeneration improvements removing some unnecessary store/loads and type
   conversions (#1881, #1879)
 * additional MPT tests added ensuring compatibility with C# implementation
   (#1993)
 * additional consistency check added to prevent node running with native
   contracts differing from the ones saved in DB (#2010)

Bugs fixed:
 * `calculatenetworkfee` RPC result used format different from C# node (#1998)
 * `CALLT` opcode was missing any price leading to wrong GAS calculations and
   different state wrt C# node (#2004)
 * '+' character was emitted directly by `jsonSerialize` method which is fine
   wrt JSON itself, but differs from C# node behavior leading to node state
   difference (#2006)
 * NEO self-transfers were not checking the amount transferred (they didn't
   change balance, but they succeeded) leading to state difference wrt C#
   implementation (#2007)

## 0.95.1 "Shiftiness" (31 May 2021)

Bringing NeoGo up to date with N3 RC3 changes this release also improves
compiler and CLI a bit.

This release is mostly compatible with 0.95.0, but you need to resynchronize
your chains to have proper stateroot data and to make new methods available to
contracts. At the same time there won't be long-term support provided for it,
just as with all previous previews and RC.

New features:
 * base58CheckEncode/base58CheckDecode methods in StdLib native contract
   (#1977, #1979)
 * getAccountState method in NeoToken native contract (#1978, #1986)
 * custom contracts and groups can now be specified for witness scopes in
   invocations from CLI (#1973)

Improvements:
 * local variable handling was refactored in the compiler, removing some
   duplicate code and improving robustness (#1921)
 * CLI help now describes how "unvote" can be done (#1985)

Bugs fixed:
 * boolean parameters to function invocations via RPC were not processed
   correctly (#1976)
 * VM CLI used too restrictive default call flags for loaded scripts (#1981)
 * IPv6 check in NNS contract was out of date wrt C# implementation (#1969)

## 0.95.0 "Sharpness" (17 May 2021)

This version mostly implements N3 RC2 protocol changes (and is fully
RC2-compatible), but also brings NEP-11 CLI support and small improvements for
node operators.

Please note that this release is incompatible with 0.94.1 and there won't be
long-term support provided for it.

New features:
 * CLI command for NEP-17 transfers now accepts `data` parameter for the
   transfer (#1906)
 * contract deployment CLI comand now also accepts `data` parameter for
   `_deploy` method (#1907)
 * NEP-11 and NEP-17 transfers from CLI can now have multiple signers (#1914)
 * `System.Runtime.BurnGas` interop was added to burn some GAS as well as
   `refuel` GAS contract method to add GAS to current execution environment
   (#1937)
 * port number announced via P2P can now differ from actual port node is bound
   to if new option is used (#1942)
 * CLI now supports full set of NEP-11 commands, including balance and
   transfers (#1918)
 * string split, memory search and compare functions added to stdlib (#1943)
 * MaxValidUntilBlockIncrement can now be configured (#1963)

Behavior changes:
 * `data` parameter is now passed in a different way to NEP-17 RPC client
   methods (#1906)
 * default (used if nothing else specified) signer scope is now
   `CalledByEntry` in CLI and RPC (#1909)
 * `SignAndPushInvocationTx` RPC client method now adds as many signatures as
   it can with the wallet given which in some cases allows CLI to create
   complete transaction without going through multisignature procedure (#1912)
 * `getversion` RPC call now returns network magic number in `network` field
   (#1927)
 * RoleManagement native contract now emits `Designation` event in
   `designateAsRole` method (#1938)
 * `System.Storage.Find` syscall now strips full prefix given when
   `FindRemovePrefix` option is used (#1941)
 * LT, LE, GT, GE VM opcodes now accept Null parameters (#1939)
 * `features` field was re-added to contract manifests, though it's not
   currently used (#1944)
 * node will reread TLS certificates (if any configured) on SIGHUP (#1945)
 * contract trusts are now expressed with permission descriptors in manifest
   (#1946)
 * NEP-11 transfers now also support `data` parameter (#1950)
 * N3 RC2 testnet magic differs from N2 RC1 testnet (#1951, #1954)
 * stdlib encoding/decoding methods now only accept inputs no longer than 1024
   bytes (#1943)
 * `System.Iterator.Create` interop was removed with all associated logic (#1947)
 * `Neo.Crypto.CheckSig` and `Neo.Crypto.CheckMultisig` interops were renamed
   to `System.Crypto.CheckSig` and `System.Crypto.CheckMultisig` (#1956)
 * oracle requests now use Neo-specific JSONPath implementation (#1916)
 * native NNS contract was removed and replaced by non-native version (#1965)

Improvements:
 * RPC errors reported by server are now more verbose for `submitblock`,
   `sendrawtransaction` calls (#1899)
 * all CLI commands that accept addresses now also accept hashes and vice
   versa (#1905)
 * code cleanup based on a number of static analysis tools (#1908, #1958)
 * CLI implementation refactoring (#1905, #1911, #1914, #1915, #1918)
 * only one state validator now sends complete stateroot message normally
   (#1953)
 * oracle HTTPS requests are now sent with User-Agent header (#1955)
 * stdlib `itoa` and `atoi` methods can now be called with one parameter
   (#1943)
 * oracle nodes are no longer on extensible payload whitelist (#1948)
 * extensible message pool is now per-sender with configurable size (#1948)
 * `static-variables` field support for debugger as well as debug data for
   `init` and `_deploy` functions (#1957)
 * user documentation for configuration options (#1968)

Bugs fixed:
 * `getproof` RPC request returned successful results in some cases where it
   should fail
 * `Transfer` events with invalid numbers were not rejected by NEP-17 tracking
   code (#1902)
 * boolean function parameters were not accepted by `invokefunction` RPC call
   implementation (#1920)
 * potential races in state validation service (#1953)
 * single state validator couldn't ever complete stateroot signature (#1953)
 * SV vote resending was missing (#1953)
 * SV vote messages used invalid (too big) ValidBlockEnd increment (#1953)
 * memory leak in state validation service (#1953)
 * NEP-6 wallets have `isDefault` field, not `isdefault` (#1961)

## 0.94.1 "Channelization" (08 Apr 2021)

This is the second and much improved N3 RC1-compatible release. We've mostly
focused on documentation and examples with this release, so there is a number
of updates in this area including oracle contract example and NEP-11 NFT
contract example. At the same time proper testnet network revealed some
implementation inconsistencies between NeoGo and C# especially in oracle and
state validation services, so there are fixes for them also.

Protocol-wise this release is compatible with 0.94.0, but MPT structures have
changed and there are known state change differences for N3 RC1 testnet, so
you need to do full node resynchronization on update from 0.94.0. Some SDK
APIs have changed also improving developer experience, but they may affect
your code. We don't plan to make more of RC1-compatible releases (the protocol
has slightly changed already since the release).

New features:
 * RPC (*Client).GetDesignatedByRole method to easily get node lists from
   RoleManagement contract (#1855)
 * `calculatenetworkfee` RPC method support (#1858)
 * RPC client now has additional methods for NEP-11 contracts and specifically
   for NNS native contract (#1857)
 * contract deployment from multisig addresses (#1886)

Behavior changes:
 * node roles for RoleManagement contract were moved into separate package
   (#1855)
 * NotaryVerificationPrice constant was moved into package of its own (#1855)
 * testnet configuration now has proper N3 RC1 testnet magic (#1856)
 * crypto.Verifiable interface was removed, now any hash.Hashable thing can be
   verified (and signed, #1859)
 * Network field was dropped from transaction.Transaction, block.Header,
   payload.Extensible, state.MPTRoot, payload.P2PNotaryRequest and
   network.Message, it was needed for proper hash calculations before recent
   protocol changes (even though this field is not a part of serialized
   representation of any of these elements), but now it's only used to
   sign/verify data and doesn't affect hashing which allowed to simplify
   interface here (#1859)
 * RPC server now returns `StateRootInHeader` option in its `getversion`
   request answers if it's used by the network (#1862)
 * NNS record types were moved to separate package (#1857)
 * MaxStorageKeyLen and MaxStorageValueLen constants were moved to storage
   package from core (#1871)
 * oracle service now accepts complete URL for other nodes RPC services (#1877)

Improvements:
 * RPC (*Client).AddNetworkFee method is now more informative in some error
   case (#1852)
 * proper NEP-17 support in unit test contract (#1852)
 * documentation updates for examples and services (#1854, #1890)
 * syscall number is now printed for failed syscalls (#1874)
 * better logging (#1883, #1889)
 * Oracle native contract interop documentation extended (#1884)
 * Oracle native contract interop extended with return codes and constants (#1884)
 * oracle smart contract example (#1884)
 * NEP-11 NFT smart contract example (#1891)

Bugs fixed:
 * node could simultaneously try to connect to the same peer multiple times in
   some cases (#1861)
 * uniqueness is enforced now for other node addresses provided by peers (#1861)
 * stateroot message hash wasn't calculated the same way as in C# (#1859)
 * state validation service P2P messages were not signed properly (#1859)
 * state.MPTRoot structure JSON representation was different from C# one (#1859)
 * stateroot messages generated by state validation service were not setting
   proper message category (#1866)
 * block persistence caches were flushed too early by MPT-managing code (#1866)
 * validated stateroot data overwrote local one which lead to node not
   functioning after restart if states were different (#1866)
 * peers delivering P2P message with validated stateroot differing from local
   one were disconnected (#1866)
 * state dump comparing script was using old Ledger native contract ID (#1869)
 * candidate registration check was made in different way from C# in native
   NEO contract leading to different execution results for erroneous voting
   transactions (#1869)
 * state change dumps were different from C# node for erroneous voting
   transactions even though contract's state was the same (#1869)
 * arguments were not completely removed from stack in erroneous
   Runtime.Notify calls leading to different stack state with C#
   implementation (#1874)
 * in case contract failed execution with THROW the node didn't print the
   message from the contract properly (#1874)
 * `getproof` RPC call output was not strictly compliant with C#
   implementation (#1871)
 * MPT node serialization and some constants were out of date wrt C#
   implementation (#1871)
 * native NEP-17 contracts could use stale balance data in some cases (#1876)
 * state validation service could lock the system during shutdown, preventing
   proper node exit (#1877)
 * state validation and oracle services were started before node reaching full
   synchronization which could lead to excessive useless traffic (#1877)
 * some native contract calls in function arguments could be miscompiled
   (#1880)
 * oracle service was accepting http URLs instead of https (#1883)
 * neofs URIs were subject to host validation in oracle service even though
   there is no host there (#1883)
 * neofs URI scheme was differing from C# implementation (#1883)
 * no default value was used for NeoFS request timeout if it's not specified
   in the configuration (#1883)
 * oracle response code was marshalled as integer into JSON (#1884)
 * MPT could grow in memory unbounded (#1885)
 * Storage.Find results could differ from C# in some cases (#1888)

## 0.94.0 "Tsessebe" (19 Mar 2021)

N3 RC1-compatible release is here. We've implemented all Neo protocol changes
(including state validation service and NeoFS support for oracles) and are
ready for testnet launch now, so that you could play with new native
contracts, VM instructions and other goodies RC1 brings with it. Some
usability improvements and documentation updates also went into this release
as well as a number of fixes stabilizing Notary subsystem (which is
NeoGo-specific protocol extension).

Please note that this release is incompatible with 0.93.0. We do plan to make
an update soon (with more examples and documentation), but there won't be
long-term support provided, Neo N3 is still on its way to mainnet (although
RC1 and testnet are major milestones on this route).

New features:
 * Compiler:
   - ellipsis support for append() to non-byte slices (#1750)
   - NEP-11 standard conformance check (#1722)
   - onNEP*Payable compliance checks (#1722)
 * you can pass files as contract arguments now with `filebytes` CLI parameter
   (#1762)
 * CLI now supports specifying addresses everywhere script hashes are accepted
   (#1758)
 * System.Contract.CreateMultisigAccount interop function (#1763)
 * SQRT and POW VM instructions (#1789, #1796)
 * new NeoFSAlphabet node role added to RoleManagement contract (#1812)
 * node can serve as state validator node (#1701)
 * oracles now support NeoFS (#1484, #1830)
 * CLI can be used to dump wallet's public keys (#1811)
 * storage fee, candidate register price and oracle request price can now be
   adjusted by committee (#1818, #1850)
 * native contracts can now be versioned (#1827)
 * RPC client was extended with price getters for native contracts (#1838)

Behavior changes:
 * NFTs no longer have "description" field (#1751)
 * P2P Notary service configuration moved to ApplicationConfiguration section
   (#1747)
 * native contract methods requiring write permission in call flags now also
   require read permission (#1777, #1837)
 * System.Contract.Call interop function now requires state read permission
   (#1777)
 * NeoGo no longer supports Go 1.13 (#1791)
 * native contract calls are now contract version aware (#1744)
 * interop wrappers for smart contracts now use `int` type for all integers
   (#1796)
 * MaxTransactionsPerBlock, MaxBlockSize, MaxBlockSystemFee settings are now a
   part of node configuration and no longer are available in Policy contract
   (#1759, #1832)
 * storage items can no longer be constant (#1819)
 * state root handling is now conformant with C# implementation (with state
   validators and vote/stateroot messages, #1701)
 * blocks no longer have ConsensusData section, primary index is now a part of
   the header (#1792, #1840, #1841)
 * `wallet multisign sign` command was renamed to `wallet sign`, it now works
   not just for multisignature contract signing, but also for multiple regular
   signers as well as contract verification signing
 * conversion interops were moved to StdLib native contract (#1824)
 * crypto interops (except basic `CheckSig` and `CheckMultiSig`) were moved to
   CryptoLib native contract (#1824)
 * PACK, UNPACK and CONVERT instructions now cost more (#1826)
 * some native contract types were adjusted (#1820)
 * native Neo's `getCommittee` and `getNextBlockValidators` methods now cost
   less (#1828)
 * block/transaction/payload hashing and signing scheme has changed (#1829,
   #1839)
 * signing context is now serialized to JSON using base64 for data (#1829)
 * System.Contract.IsStandard interop was removed (#1834)
 * notifications are no longer allowed for safe contract methods (#1837)

Improvements:
 * verification script are now allowed to make contract calls (#1751)
 * extensible payloads now have the same size limit as other P2P messages
   (#1751)
 * error logging is more helpful now in some cases (#1747, #1757)
 * function inlining support in compiler for internal intrinsics, interop
   refactoring (#1711, #1720, #1774, #1785, #1804, #1805, #1806, #1796, #1809)
 * documentation updates (#1778, #1843)
 * `sendrawtransaction` and `submitblock` RPC calls now return more detailed
   information about errors for failed submissions (#1773)
 * NeoGo now supports Go 1.16 (#1771, #1795)
 * NEP-17 transfer tracking was optimized to avoid some DB accesses (#1782)
 * interop wrappers added for SIGN/ABS/MAX/MIN/WITHIN instructions (#1796)

Bugs fixed:
 * `designateAsRole` method returned value while it shouldn't (#1746)
 * deleting non-existent key could lead to node panic during MPT calculation
   (#1754)
 * some invalid IPv4 were accepted by name service contract (#1741)
 * some legitimate IPv6 addresses were rejected by name service (#1741)
 * compiler: append() to byte array produced wrong results for bytes with
   >0x80 values (#1750)
 * wrong notary-signed transaction size in notifications leading to client
   disconnects (#1766)
 * CALLT wasn't checking permission to read states and make calls in call
   flags (#1777)
 * proper escaping wasn't done in some cases on VM stack item conversion to
   JSON (#1794)
 * improper network fee calculation for complex multi-signed transactions in
   some cases (#1797)
 * importing package with the same name as compiled one could lead to
   incorrect compiler behavior (#1808)
 * boolean values were emitted as integers by compiler leading to some
   comparison failures (#1822)
 * `invokecontractverify` wasn't calculating proper GAS price of verification
   using contract (#1825)
 * ContractManagement contract wasn't returning NULL value from `getContract`
   method if contract is missing (#1851)

## 0.93.0 "Hyperproduction" (12 Feb 2021)

This is a 3.0.0-preview5 compatible release with important protocol changes,
improved smart contract interop interface for native contracts (it's much
easier now to use them) and complete Notary subsystem which is a NeoGo
experimental protocol extension for P2P signature collection.

Please note that this release is incompatible with 0.92.0 and there are no
plans for long-term support of it, Neo 3 is still changing and improving.

The release is tested with preview5 testnet data (and one of testnet CNs is
already a neo-go node) up to 48K blocks and it has exactly the same storage
data except for the Ledger contract that technically can differ between nodes
(it's not a part of state proper), and in case of neo-go it's intentionally
different (but this doesn't affect contract's functionality and state roots
compatibility).

New features:
 * "ProtocolNotSupported" oracle response code (#1630)
 * POPITEM VM opcode (#1670)
 * CALLT VM opcode and contract tokens support (#1673)
 * extensible P2P payloads (#1667, #1674, #1706, #1709)
 * contract method overloading (#1689)
 * oracle module (#1427, #1703)
 * NNS native contract (#1678, #1712, #1721)
 * complete P2P Notary subsytem (experimental protocol extension, use only on
   private networks, #1658, #1726)
 * Ledger native contract (#1696)
 * `getblockheadercount` RPC call (#1718)
 * native contract wrappers for Go smart contracts (#1702)
 * `getnativecontracts` RPC call (#1724)

Behavior changes:
 * VM CLI now supports and requires manifests to properly work with NEF files
   (#1642)
 * NEP-17-related CLI commands now output GAS balance as floating point numbers
   (#1654)
 * `--from` parameter can be omitted now for NEP-17 CLI transfers, the default
   wallet address will be used in this case (#1655)
 * native contracts now use more specific types for methods arguments (#1657)
 * some native contract names and IDs have changed (#1622, #1660)
 * NEF file is stored now in contract's state instead of script only which
   also affects RPC calls and ContractManagement's interface
 * call flag definitions were moved to a package of their own (#1647)
 * callback syscalls were removed (#1647)
 * calling a contract now requires specifying allowed flags (and `CallEx`
   syscall was removed, #1647)
 * iterator/enumerator `Concat` calls were removed (#1656)
 * `System.Enumerator.*` syscalls were removed (#1656)
 * `System.Storage.Find` interface was reworked (#1656)
 * NEF file format was changed merging compiler and version fields, adding
   reserved fields and tokens (#1672)
 * registering as committee/validator candidate now costs 1000 GAS (#1684)
 * dbft now uses extensible P2P payloads (#1667)
 * contract hashing scheme was changed now including names in the mix (#1686)
 * GAS fees JSON marshalling was changed to plain integers (#1687, #1723)
 * native methods requiring committee signature now fail the script instead of
   returning `false` (#1695)
 * native ContractManagement contract now has two `deploy` methods, with
   additional data and without it (#1693)
 * updated contract manifest now can't change contract's name (#1693)
 * default values of native contracts were moved to storage from code (#1703)
 * blocked accounts now store empty string instead of `01` byte (#1703)
 * testnet magic number was changed for preview5 (#1709, #1715)
 * `onPayment` method was renamed to `onNEP17Payment` (#1712)
 * manifests are stored and accessed as stack items instead of JSON (#1704)
 * zero-length "Headers" packet is a protocol error now (#1716)
 * `getstorage` RPC call now uses base64 instead of hex for input/output
   (#1717)
 * state dumper and comparer now use base64 instead of hex (#1717)
 * deployed contracts and manifests are now checked for correctness (#1729)
 * transaction scripts are now checked for correctness before execution
   (#1729)

Improvements:
 * default VM interop prices were adjusted (#1643)
 * batched MPT updates (#1641)
 * you can use `-m` now for manifest parameter of contract deploying command
   (#1690)
 * transaction cosigners can be specified with addresses now (#1690)
 * compiler documentation was updated (#1690)

Bugs fixed:
 * oracle response transaction can't be correctly evicted from the mempool
   (#1668)
 * the node left with zero peers didn't initiate reconnections to seeds in rare
   cases (#1671)
 * native contracts supposed to check for committee witness in fact checked
   for validators witness (#1679)
 * it was allowed for contracts to have non-bool `verify` methods (#1689)
 * previous proposal reuse could lead to empty blocks accepted even if there
   are transactions in the mempool (#1707)
 * NEO contract's `getCommittee` method name was misspelled (#1708)
 * CLI wasn't correctly handling escape sequences (#1727)
 * init and deploy methods could be misoptimized leading to execution failures
   (#1730)
 * NEP-17 contract example was missing `onNEP17Payment` invocation (#1732)
 * missing state read privilege could lead to transaction failures for
   transfers from CLI or when using native contract wrappers (#1734, #1735)
 * some native contract methods had different parameter names and return
   output types (#1736)

## 0.92.0 "Fermentation" (28 Dec 2020)

NeoGo project is closing year 2020 with 3.0.0-preview4 compatible release that
also has much improved performance, a lot of updates to compiler and SDK and
some experimental protocol extensions. This release also is the most tested
release of NeoGo ever, we've reached 83% code coverage (Neo 2.x only has
66%).

Please note that this release is incompatible with 0.91.0 and there are no
plans for long-term support of it, Neo 3 is still changing and improving.

Protocol-wise this release is tested with preview4 testnet (including working
in consensus with C# nodes) and it is compatible with it even though there are
some known storage change mismatches between NeoGo and C# (functionally the
contents is the same, this mismatch is caused by JSON handling differences and
needs to be addressed at the protocol level).

New features:
 * "high priority" transaction attribute (#1341)
 * "oracle response" transaction attribute (#1407, #1520, #1573)
 * new GAS distribution and committee update scheme (#1364, #1529, #1518,
   #1542, #1549, #1636, #1639)
 * oracle native contract (#1409, #1432, #1474, #1476, #1521, #1528, #1548,
   #1556, #1625)
 * designation native contract (#1451, #1504, #1519)
 * support for `_deploy` method (#1452, #1466)
 * `MaxTraceableBlocks` parameter can now be configured (#1520)
 * `KeepOnlyLatestState` configuration option to drop old MPT data (#1553)
 * `StateRootInHeader` configuration option to include state root data in the
   header (it's a protocol extension, so use with care, #1500)
 * NEP-5 was replaced by NEP-17 (#1558, #1574, #1617, #1636)
 * `RemoveUntraceableBlocks` configuration option to perform old (unreachable)
   block and transaction purging (#1561)
 * stable deployed contract hashes (#1555, #1616, #1628)
 * `Safe` method flag for contract manifests (#1597, #1607)
 * native Management contract to deploy/update/destroy contracts (#1610,
   #1624, #1636)
 * Compiler/SDK:
   - base58 encoding/decoding interops for smart contracts (#1350, #1375)
   - you can use aliases now when importing interop packages (#397)
   - `+=` operator is now supported for strings (#1351)
   - `switch` without statement support (#1355)
   - `make()` support for maps and slices using basic types (#1352)
   - `copy()` support for byte slices (#1352, #1383)
   - `iota` support (#1361)
   - support for basic function literals (#1343)
   - new variable initialization is now supported in `if` statements (#1343)
   - `defer` is now supported (#1343)
   - `recover()` support for exception handling (#1343, #1383)
   - `delete()` support (#1391)
   - `util.Remove()` function is added for smart contracts to remove elements
     from slice (#1401)
   - `interop` package now provides specific type aliases like Hash160/Hash256
     for smart contracts to use (it affects generated manifests, #1375, #1603)
   - variables and function calls support in struct and slice literals (#1425)
   - atoi/itoa encoding/decoding interops for smart contracts (#1530, #1533)
   - contracts specifying NEP-17 as supported standard are now checked for
     interface compliance (#1373)
   - `contract.CallEx` function is now available to contracts that allows
     specifying flags for contract called (#1598)
 * CLI:
   - support for array parameters in invocations (#1363, #1367)
   - contract addresses can now be imported into wallet (#1362)
   - deploying/invoking from multisignature accounts (#1461)
 * RPC:
   - `getcommittee` RPC call (#1416)
   - limits and paging are now supported for `get*transfers` calls (#1419)
   - `getunclaimedgas` RPC call now also supports passing address as a
     parameter (#1418)
   - `getcontractstate` now also accepts addresses, IDs and names (for native
     contracts, #1426)
   - batched JSON-RPC requests support (#1514)
   - `invokecontractverify` RPC call to run verification scripts (#1524)
 * P2P notaries subsystem (configurable `P2PSigExtensions` protocol extension,
   use with care):
   - optional `NotValidBefore` transaction attribute (#1490)
   - optional `Conflicts` transaction attribute (#1507)
   - native Notary contract (#1557, #1593)
   - notary request P2P payload (#1582)

Behavior changes:
 * converting items to boolean now fail for strings of bytes longer than 32
   (#1346)
 * consensus messages now use uint8 field for validator indexes (#1350)
 * maximum possible try-catch nesting is now limited to 16 levels (#1347)
 * maximum manifest size increased to 64K (#1365, #1555)
 * required flags changed for many interop functions (#1362)
 * compiler no longer generates code to log `panic()` message (#1343)
 * `GetBlock`, `GetTransaction` and similar interop functions now return
   pointers to structures (#1375)
 * calling script hash now also is accounted for by CheckWitness interop
   (#1435, #1439)
 * CLI is using `--address` parameter everywhere it's needed (some commands
   used `--addr` previously (#1434)
 * VM now restricts comparable byte array size to 64K (#1433)
 * `FeeOnly` witness scope was renamed to `None` (#1450)
 * `getvalidators` RPC call was renamed to `getnextblockvalidators` (#1449)
 * `emit.Opcode` is now `emit.Opcodes`, allowing for variadic specification of
   opcodes (#1452)
 * `CalculateNetworkFee` was moved to `fee.Calculate` (#1467)
 * fault exception string is now returned for failed invocations (#1462)
 * `runtime.GetInvocationCounter` no longer errors (#1455)
 * `invoke*` RPC calls now also return `transaction` field (#1418)
 * `getversion` RPC call now also returns network magic number (#1489)
 * RPC calls now return data in base64 instead of hex (#1489, #1525, #1537)
 * blocked accounts interface and storage was changed in Policy contract (#1504)
 * voting fee is lower now (#1510)
 * blocks are now processed with two execution triggers, `OnPersist` and
   `PostPersist`, `getapplicationlog` RPC call was updated to support passing
   trigger type (#1515, #1531, #1619)
 * storage fee formula has changed (#1517)
 * `MaxValidUntilBlockIncrement` is now 5760 instead of 2102400 (#1520)
 * Policy contract no longer saves default values during initialization
   (#1535)
 * opcode pricing was changed and now it's adjustable (#1538, #1615)
 * contracts no longer have `IsPayable` (see NEP-17) and `HasStorage` (they
   all have it by default now) features (#1544)
 * notification size is restricted now (#1551)
 * unsolicited `addr` messages are now treated as errors (#1562)
 * native contracts no longer have `name()` methods, it is now a part of
   manifest (#1557)
 * transaction fees, invocation GAS counters and unclaimed GAS values are now
   returned as strings with floating point values from RPC calls (#1566,
   #1572, #1604)
 * NEF format was changed (#1555)
 * `engine.AppCall()` interop was renamed to `contract.Call()` (#1598)
 * call flags were renamed (#1608)
 * deploying contract now costs at minimum 10 GAS and MaxGasInvoke
   configuration was adjusted to account for that (the fee is configurable by
   the committee, #1624, #1635)

Improvements:
 * a lot of new tests added (#1335, #1339, #1341, #1336, #1378, #1452, #1508,
   #1564, #1567, #1583, #1584, #1587, #1590, #1591, #1595, #1602, #1633,
   #1638)
 * a number of optimizations across all node's components applied (#1342,
   #1347, #1337, #1396, #1398, #1403, #1405, #1408, #1428, #1421, #1463,
   #1471, #1492, #1493, #1526, #1561, #1618)
 * smartcontract package now provides function to create simple majority
   multisignature contract (in addition to BFT majority, #1341)
 * `AddNetworkFee()` now supports contract addresses (#1362)
 * error handling and help texts for CLI wallet commands (#1434)
 * compiler emitting short jump instructions if possible (#805, #1488)
 * compiler emitting jump instructions with embedded conditions where possible
   (#1351)
 * transaction retransmission mechanism added to mempool (#1536)
 * parallel block fetching (#1568)
 * Binary and Runtime interops refactored to separate packages (#1587)
 * message broadcasts now finish successfully if the message is sent to 2/3 of
   peers (#1637)

Bugs fixed:
 * TRY opcode implementation was not allowing for 0 offsets (#1347)
 * compiler wasn't dropping unused elements returned from calls (#683)
 * MEMCPY with non-zero destination index was not working correctly (#1352)
 * asset transfer from CLI didn't work (#1354)
 * specifying unknown DB type in configuration file induced node crash (#1356)
 * address specifications in configuration file didn't work correctly (#1356)
 * RPC server wasn't processing hashes with "0x" prefix in parameters (#1368)
 * incorrect context unloding on exception handling (#1343)
 * attempt to get committee only returned validators if there was no voting on
   chain (#1370)
 * block queue could be attacked with wrong blocks to cause OOM (#1374)
 * token sale example wasn't checking witness correctly (#1379)
 * structure methods were added to generated manifests (#1381)
 * type conversions in `switch` and `range` statements were compiled as
   function calls (#1383)
 * RPC server result format wasn't conforming to C# implementation for
   `getapplicationlog` and `invoke*` (#1371, #1387)
 * subslicing non-byte slices was miscompiled (it's forbidden now, #1401)
 * potential deadlock in consensus subsystem (#1410)
 * race in peer connection closing method (#1378)
 * race in MPT calculation functions (#1378)
 * possible panic on shutdown (#1411)
 * block-level `getapplicationlog` result had block hash in it (#1413)
 * fail CN execution if wrong password is provided in the configuration
   (#1419)
 * tx witness check didn't account for GAS properly when several witnesses are
   used (#1439)
 * map keys longer than 64 bytes were allowed (#1433)
 * unregistered candidate with zero votes wasn't removed (#1445)
 * standard contract's network fee wasn't calculated correctly (#1446)
 * witness checking wasn't taking into account transaction size fee (#1446)
 * sending invalid transaction from the CLI wasn't prevented in some cases
   (#1448, #1479, #1604)
 * `System.Storage.Put` wasn't accounting for new key length in its GAS price
   (#1458)
 * blocks can't have more than 64K transactions (#1454)
 * Policy native contract wasn't limiting some values (#1442)
 * MerkleBlock payload wasn't serialized/deserialized properly (#1454, #1591)
 * partial contract updates were not always possible (#1460)
 * potential panic on verification with incorrect signature size (#1467)
 * CLI attempted to save transaction when it wasn't requested (#1467)
 * VM allowed to create bigger integers than it should support (#1464)
 * some protocol limits were not enforced (#1469)
 * iterating over storage items could produce incorrect KV pairs when using
   LevelDB or BadgerDB (#1478)
 * stale transaction were not deleted from the mempool (#1480)
 * node panic during block processing with BoltDB (#1482)
 * node that failed to connect to seeds on startup never attempted to
   reconnect to them again (#1486, #1592)
 * compiler produced incorrect code for if statements using function calls
   (#1479)
 * invocation stack size check wasn't performed in some cases (#1492)
 * incorrect code produced by the compiler when assigning slices returned from
   functions to new variables (#1495)
 * websocket client closing connection on new events (#1494)
 * minor `getrawtransaction`/`gettransactionheight` and NEP5-related RPC
   implementation incompatibilities (#1543, #1550)
 * VM CLI breakpoint wasn't stopping before the instruction (#1584)
 * VM CLI was incorrectly processing missing parameter error (#1584)
 * wallet conversion wasn't performed correctly (#1590)
 * node didn't return all requested blocks in response to `getblocks` P2P
   requests (#1595)
 * CN didn't request transactions properly from its peers in some cases
   (#1595)
 * incorrect manifests generated for some parameter types (#1599)
 * incorrect code generated when no global variables are present, but there
   are some global constants (#1598)
 * native contract invocations now set proper calling script hash (#1600)
 * byte string and buffer VM stack items conversion to JSON differed from C#
   (#1609)
 * when mempool is full new transaction's hash could still be added into it
   even if it is to be rejected afterwards (#1621)
 * CN wasn't always performing timestamp validation correctly (#1620)
 * incorrect stack contents after execution could stop block processing
   (#1631)
 * `getapplicationlog` RPC call handler wasn't validating its parameters
   properly, potentially leading to node crash (#1636)
 * a peer could be connected twice in rare circumstances (#1637)
 * missing write timeout could lead to broadcasting stalls (#1637)

## 0.91.0 "Ululation" (18 August 2020)

We've updated NeoGo for 3.0.0-preview3 compatibility implementing all the
appropriate protocol changes as well as improving NeoGo-specific
components. This release brings with it significant changes for smart
contracts, both in terms of Neo protocol changes (no more there is a single
entry point! execution environment has also changed in lots of ways) and Go
smart contract compiler updates and fixes.

Please note that this release is incompatible with 0.90.0 and there will be no
long-term support provided for it, Neo 3 is still changing and
improving. If you have any wallets used with 0.90.0 release you'll need to
regenerate them from private keys because of changes to verification scripts
that also changed hashes and addresses.

But nonetheless it is tested to be compatible with preview3 testnet for up to
68K of blocks in terms of storage changes, with neo-debugger for debug data
produced by the compiler and with consensus process for heterogeneous setups
(like 2 neo-go CNs with 2 C# CNs).

New features:
 * secp256k1 signature checks added to interop functions
   (Neo.Crypto.VerifyWithECDsaSecp256k1 and
   Neo.Crypto.CheckMultisigWithECDsaSecp256k1 syscalls,
   crypto.ECDsaSecp256k1Verify and crypto.ECDSASecp256k1CheckMultisig interop
   functions, #918)
 * RIPEMD160 hash added to interop functions (Neo.Crypto.RIPEMD160 syscall,
   crypto.RIPEMD160 interop function, #918, #1193)
 * "NotFound" P2P message (#1135, #1333)
 * base64 encoding/decoding interop functions (binary.Base64Encode and
   binary.Base64Decode, #1187)
 * new contract.GetCallFlags interop (System.Contract.GetCallFlags syscall)
   implemented (#1187)
 * it is possible now to create iterators and enumerators over primitive VM
   types in smart contracts (#1218)
 * runtime.Platform interop (System.Runtime.Platform syscall) is now available
   to smart contracts in Go (#1218)
 * storage.PutEx interop (System.Storage.PutEx syscall) is now available to
   smart contracts in Go (#1221)
 * exceptions support in VM (#885)
 * CLI conversion utility functions for addresses/hashes/etc (#1207, #1258)
 * multitransfer transactions now can be generated with RPC client or CLI
   (#940, #1260)
 * System.Callback.* syscalls for callback creation and execution (callback.*
   interop functions, #1197)
 * MPT implementation was added (#1235)
 * Policy native contract now also contains MaxBlockSystemFee setting (#1195)
 * getting blocks by indexes via P2P is now supported (#1192)
 * limited pointer support was added to the compiler (#1247)
 * voting support in CLI (#1206, #1286)

Behavior changes:
 * crypto.ECDsaVerify interop function was renamed to
   crypto.ECDsaSecp256r1Verify now that we have support for secp256k1 curve
   (#918)
 * many RPC requests/responses changed names used for data fields (#1169)
 * runtime.Notify interop function now requires a mandatory UTF8 name
   parameter (#1052) and this name can be used to filter notifications (#1266)
 * sendrawtransaction and submitblock RPC calls now return a hash instead of
   boolean value in case of success (#1216)
 * System.Runtime.Log syscall now only accepts valid UTF8 strings no longer
   than 1024 bytes (#1218)
 * System.Storage.Put syscall now limits keys to 64 bytes and values to 1024
   bytes (#1221)
 * PUSHA instruction now works with relative code offset (#1226)
 * EQUAL instruction no longer does type conversions, so that values of
   different types are always unequal (#1225)
 * verification scripts now can't use more than 0.5 GAS (#1202)
 * contracts no longer have single entry point, rather they export a set of
   methods with specific offsets. Go smart contract compiler has been changed
   accordingly to add all exported (as in Go) methods to the manifest
   (but with the first letter being lowercased to match NEP-5 expections,
   #1228). Please also refer to examples changes to better see how it affects
   contracts, manifests and configuration files (#1296)
 * native contracts are now called via Neo.Native.Call syscall (#1191)
 * compressed P2P payloads now also contain their uncompressed size (#1212,
   #1255)
 * NEF files now use double SHA256 for checksums (#1203)
 * VM's map keys and contract methods now can only contain valid UTF-8 strings
   (#1198)
 * stack items now can be converted to/from JSON natively (without
   smartcontract.ContractParameters intermediate) which is now used for
   invoke* RPC calls and application execution logs (#1242, #1317)
 * invoking Policy native contracts now requires AllowsStates (to get
   settings) or AllowModifyStates (to change setting) flags (#1254)
 * Transaction now has Signers field unifying Sender (the first Signer) and
   Cosigners, a Signer can have FeeOnly or any other regular witness scope
   (#1184)
 * verification scripts no longer have access to blockchain's state (#1277)
 * governance scheme was changed to delegated committee-based one. The number
   of validators is now specified with ValidatorsCount configuration option,
   standby validators are no longer being registered by default (#867, #1300)
 * Go 1.13+ is now required to build neo-go (#1281)
 * public contract methods now always return some value and this is being
   checked by the VM (#1196, #1331, #1332)
 * runtime interop package now exports triggers as proper constants rather
   than functions (#1299)
 * RPC client no longer has SetWIF/WIF methods that didn't do anything useful
   anyway (#1328)

Improvements:
 * Neo.Crypto.CheckMultisigWithECDsaSecp256r1 syscall is now available via
   crypto.ECDSASecp256r1CheckMultisig interop function (#1175)
 * System.Contract.IsStandard syscall now also checks script's container (#1187)
 * syscalls no longer have allowed triggers limitations (#1205)
 * better testing coverage (#1232, #1318, #1328)
 * getrawmempool RPC call now also supports verbose parameter (#1182)
 * VMState is no longer being stored as a string for application execution
   results (#1236)
 * manifest now contains a list of supported standards (#1204)
 * notifications can't be changed now by a contract after emitting them
   (#1199)
 * it is possible to call other contracts from native contracts now (#1271)
 * getnep5transfers now supports timing parameters (#1289)
 * smartcontract package now has CreateDefaultMultiSigRedeemScript that should
   be used for BFT-compliant "m out of n" multisignature script generation
   (#1300)
 * validators are always sorted now (standby validators were not previously,
   #1300)
 * debug information now contains all file names (#1295)
 * compiler now accepts directory to compile a package, only one file could be
   passed previously (#1295)
 * some old no longer used functions and structures were removed (#1303)
 * contract inspection output was improved for new Neo 3 VM instructions (#1231)
 * ping P2P message handling was changed to trigger block requests (#1326)

Bugs fixed:
 * inability to transfer NEO/GAS from deployed contract's address (#1180)
 * System.Blockchain.GetTransactionFromBlock syscall didn't pick all of its
   arguments from the stack in some error cases (#1187)
 * System.Contract.CallEx syscall didn't properly check call flags (#1187)
 * System.Blockchain.GetContract and System.Contract.Create syscalls returned
   an interop interface instead of plain well-defined structure (#1187)
 * System.Contract.Update syscall's manifest checks were improved, return
   value was fixed (#1187)
 * getnep5balances and getnep5transfers RPC calls now support addresses in
   their parameters (#1188)
 * rare panic during node's shutdown (#1188)
 * System.Runtime.CheckWitness, System.Runtime.GetTime syscalls are only allowed to be called with
   AllowStates flag (#1218)
 * System.Runtime.GasLeft syscall result for test VM mode was wrong (#1218)
 * getrawtransaction RPC call now also returns its VM state after execution
   (#1183)
 * getnep5balances and getnep5transfers RPC calls now correctly work for
   migrated contracts (#1188, #1239)
 * compiler now generates correct code for global variables from multiple
   files (#1240)
 * compiler now correctly supports exported contracts and variables in
   packages (#1154)
 * compiler no longer confuses functions with the same name from different
   packages (#1150)
 * MaxBlockSize policy setting was not enforced (#1254)
 * missing scope check for signers (#1244)
 * compiler now properly supports init() functions (#1253, #1295)
 * getvalidators RPC call now returns zero-length array of validators when
   there are no registered candidates instead of null value (#1300)
 * events were not added to the debug data (#1311, #1315)
 * RPC client's BalanceOf method was lacking account parameter (#1323)
 * VM CLI debugging commands didn't really allow to step through the contract
   (#1328)
 * recovery message decoding created incorrect PrepareRequest payload that
   lead to consensus failures (#1334)

## 0.90.0 "Tantalization" (14 July 2020)

The first Neo 3 compatible release of neo-go! We've targeted to make it
compatible with preview2 release of Neo 3, so it only contains features
available there, but at the same time this makes the node more useful until we
have some more up to date reference version. It's a completely different
network, so almost everything has changed and it's hard to describe it with
the same level of details we usually do (but we'll provide them for subsequent
releases where the changeset is going to be lower in size). Please note that
this is a preview-level release and there won't be long-term support provided
for it, Neo 3 is evolving and the next release won't be compatible with this
one.

Main Neo 3 features in this release:
 * no UTXO
 * native contracts
 * new VM
 * scoped witnesses for transaction
 * updated interop/syscalls set
 * contract manifests
 * more efficient P2P protocol

Things that have also changed:
 * transaction format
 * block format
 * address format
 * wallets
 * RPC protocol
 * notification subsystem
 * executable format output for compiler

Compatibility level of this neo-go release:
 * identical storage changes compared to C# node for 378K blocks of preview2
   testnet
 * debugging info produced is compatible with preview2-compatible neo-debugger
 * running consensus nodes in heterogeneous setup is possible (2 neo-go CNs
   with 2 C# CNs, for example)

Changes specific to neo-go:
 * some CLI parameters like wallet path or RPC endpoint URL have been unified
   across all commands and thus have changed in some of them (refer to CLI
   help for details)
 * as an extension we support post-preview2 cosigners parameter for
   invokefunction RPC calls (see neo-project/neo-modules#260)
 * Go compiler now supports comparisons with nil properly
 * we no longer provide bootstrapping 6k block dump for private networks, you
   have 30000000 GAS right in the genesis block and it's not hard to make use
   of it (see
   [neo-go-sc-wrkshp](https://github.com/nspcc-dev/neo-go-sc-wrkshp) for an
   example of how to use it)
 * we have a conversion tool for your old Neo 2 wallets (`wallet convert`
   command), so you can reuse keys on Neo 3 networks
 * util.Equals interop function may not function the way you expect it to due
   to Neo VM changes, it still is an EQUAL opcode though. This interop may be
   removed in the future.

## Older versions

Please refer to the [master-2.x branch
CHANGELOG](https://github.com/nspcc-dev/neo-go/tree/master-2.x/CHANGELOG.md)
for versions prior to 0.90.0 (that are Neo 2 compatible, unlike 0.90.0+ that
are Neo 3 compatible).