Migrating to FCMP++
What happens to coins, wallets and nodes — and where we are now
FCMP++ activates with a hard fork. Old coins don't need to be moved anywhere: they automatically join the tree and are spent with the new transaction type. Seed phrases and addresses keep working. Users only need to update their wallet and node in time.
Status (November 2026)
- FCMP++ is not yet active on mainnet; there is no official hard-fork date.
- Public testing is under way: a test network fork ("stressnet") happened in October 2026.
- The lead developer published a non-binding draft plan: a first fork-enabled release in autumn 2026, a fully featured release (hardware wallets, multisig) in early winter, activation tentatively in early 2027.
Watch for announcements on getmonero.org and in the monero-project/monero repository. Dates quoted by third-party sites are often wrong.
What happens at the hard fork
- The tree is built from all existing outputs. Every RingCT output (and older pre-RingCT outputs, brought to a common form) becomes a leaf. Nodes do this in advance or while upgrading the database.
- From the fork height on, the network accepts only the new transaction type: membership proof + SA+L instead of rings.
- Key images persist. An output spent in a RingCT transaction already left a key image, and trying to spend it again via FCMP++ yields the same
L— and is rejected.
What users should do
| Who | What to do |
|---|---|
| Ordinary user | Update the wallet to a fork-ready version. Move nothing. |
| Node operator | Update monerod before the fork; otherwise the node stays on the old chain. |
| Hardware wallet | Wait for firmware and a desktop app with FCMP++ support. |
| Multisig | Multisig schemes change; watch for wallet versions supporting the new protocol. |
| Services, exchanges | Update monero-wallet-rpc integrations; check the new transaction format and fees. |
A hard fork is a favourite phishing excuse: "move your coins to a new address", "update your seed", "claim an airdrop". The switch to FCMP++ requires no moving of coins, entering seeds on websites or "migrating" wallets. Download software only from official sites and verify signatures/hashes.
What will noticeably change
- Transaction size and fees will grow: an FCMP++ input is heavier than a ring.
- Building a transaction takes longer on weak devices (seconds instead of fractions of a second).
- Node sync gets heavier on CPU: proofs are costlier to verify.
- Sender privacy improves dramatically — with no action from the user.
Carrot — at the same time or right after
Carrot is designed for FCMP++ and introduced with it. Old wallets keep working in "legacy" mode, and new ones can create wallets with the extended key hierarchy. Compatibility details are in the Carrot specification.