4.8.3-ecx3

Pre-release. Unsigned. First build for eCash MAINNET.

Third tagged build of Electrum eCash, and the first for the real eCash chain, built on upstream Electrum 4.8.3 (which, with 4.8.2, is an upstream security release).

What changed since 4.8.1-ecx2

• Mainnet parameters. Fork height 973,728, fork difficulty 0x1901a6e1, replay-protection nLockTime 499999998 (LOCKTIME_THRESHOLD - 2; betanet used - 1). Server ssl://explorer.ecash.ninja:50002, explorer https://explorer.ecash.ninja/. Source: ecash-com/bitcoin master and drivechain.dev/config, network ecash.
• New post-fork difficulty algorithm. eCash mainnet retargets every 288 blocks after the fork with a 6:1 dampened adjustment (Bitcoin: every 2016, undamped). The client now computes each header's target per height from the preceding window instead of per 2016-header chunk. Details in FORK.md.
• Rebased onto Electrum 4.8.3, picking up the 4.8.2 and 4.8.3 security fixes.
• Checkpoints extended to height 971,711 (shared Bitcoin history, cross-checked against mempool.space). Pins stop at the fork by design.

Status of verification

The fork block (973,728) had not been mined when this was built. The client was verified against the mainnet server up to its tip at 973,579 with zero rejected headers, and the post-fork difficulty code is covered by unit tests written against the node's pow.cpp, but it has not yet seen a real post-fork header. Expect a follow-up release once the chain is past its first two retargets (block 974,304) and the final checkpoint can be added.

Alphanet and betanet are dead. A data directory from either will not sync: delete ~/.electrum-ecash/blockchain_headers and ~/.electrum-ecash/forks before first run. Betanet-era transactions carry the old locktime marker and are not valid on mainnet.

Built from commit 7349061 (tag 4.8.3-ecx3) by CI run 40745642213. The tests workflow shows red on this tag for one reason: test_rbf, an upstream test that asserts a transaction with nLockTime 0, was missing from our exclusion list. It is back in the list in the next commit on ecx/4.8.3; no code differs. Locally: 1146 passed, 0 failed.

Read this before downloading

• Nothing here is code-signed. macOS Gatekeeper will refuse to open the app; Windows SmartScreen will warn. Working around those warnings is a habit worth not building on software that holds Bitcoin keys. Signing and notarization are outstanding.
• There is no update mechanism. If a serious bug is found there is no way to reach you. Watch this repository.
• Do not put value you care about into this build.
• Not affiliated with, endorsed by, or supported by the Electrum developers or Electrum Technologies GmbH. Do not report issues with this software to them.

Downloads

Platform	File
Windows installer	electrum-ecash-4.8.3-ecx3-setup.exe
Windows standalone	electrum-ecash-4.8.3-ecx3.exe
Windows portable	electrum-ecash-4.8.3-ecx3-portable.exe
Linux AppImage	electrum-ecash-4.8.3-ecx3-x86_64.AppImage
macOS (arm64 only)	electrum-ecash-4.8.3-ecx3-unsigned.dmg
Source tarball	Electrum-eCash-4.8.3.tar.gz
Source only (no bundled deps)	Electrum-eCash-4.8.3-sourceonly.tar.gz

The macOS build will not run on an Intel Mac. Every hosted Intel macOS runner has been retired, so CI can only produce arm64. Intel users should run from source.

This build does not collide with an existing Bitcoin Electrum install: separate data directory (~/.electrum-ecash), separate launcher (electrum-ecash), separate install location, separate bundle and package identifiers, and it registers ecx: rather than bitcoin: URIs.

Verifying

shasum -a 256 -c SHA256SUMS.txt

These checksums establish only that your download matches what CI produced. They are not a signature and prove nothing about who built it. Until GPG signing and reproducible-build attestation exist, the meaningful check is to read the source and build it yourself: git log 4.8.3..4.8.3-ecx3 is the whole fork, on top of upstream's GPG-signed 4.8.3 tag.

What this is

ECX is a Bitcoin hard fork whose addresses are byte-identical to Bitcoin's. This wallet talks only to ECX, sets ECX's replay-protection nLockTime on every transaction, and refuses to broadcast one that could replay onto Bitcoin.

See FORK.md for what each change does, and its Known gaps section for what is still missing -- including that fiat rates would price ECX at the Bitcoin price if enabled, and that the coin-splitting feature is not built yet.