Layer 1 blockchain
Grin ticker GRIN
Summary
Grin implements Mimblewimble and is secured by Cuckatoo32+ proof of work with a 60-second block target and a fixed reward of 60 GRIN per block, forever. By default, amounts sit inside Pedersen commitments with range proofs and there are no on-chain addresses; each transaction leaves a kernel with a signature, a fee shown in the clear and an optional lock height. Nodes check that all commitments sum to the expected supply, which lets spent outputs be pruned while every kernel is kept. 238911152425
Design
- System
- Layer 1 blockchainIndependent proof-of-work chain implementing Mimblewimble, launched 15 January 2019 with its own Rust codebase; it is not a sidechain, extension block or fork of another chain.
- Settlement family
- Its own design
- Scarce resource
- Work (proof of work)
- State model
- UTXO
- Finality
- Probabilistic
- Who makes blocks
- Miners propose blocks by finding 42-cycles in large Cuckatoo graphs with GPUs or purpose-built hardware, solo or through pools. At launch a second, ASIC-resistant algorithm (Cuckaroo29) was targeted to produce 90% of blocks; its share fell steadily to zero over two years, its variant was changed at each six-monthly hard fork, and it was dropped at the fourth. The primary algorithm began as Cuckatoo31+ and was narrowed to Cuckatoo32+ during 2020.
- Fork choice
- Every block header records the chain's total difficulty, and nodes follow the valid chain with the most accumulated work. Settlement is probabilistic. A node not running in archive mode keeps about one week of full blocks (10,080) and can roll back only that far; a fork that starts deeper than that forces it to re-sync chain state instead of simply switching branches.
Qualifications
- State model · Partial. Output-based: outputs are bare commitments with no address and no visible amount, spent outputs can be pruned from history, and transactions are built interactively by sender and receiver.
- Block explorer visibility · Partial. Explorers can show blocks, kernels with their fees and lock heights, and output commitments, but not amounts, senders, receivers or balances. Kernel counts approximate transaction counts per block.
- Settlement family · Partial. Grin is an independent chain implementing Mimblewimble with its own Rust codebase, secured by Cuckatoo32+ proof of work, with no scripts or on-chain addresses, so its settlement family is recorded as other.
Tradeoffs
- Emphasizes
- Decentralization and Security Contested
- Gives up
- Base-layer capacity and convenience: one-minute blocks with a weight cap the code comments put at about 1.5 MB, transactions the receiver must help build, no scripting or token layer, and constant issuance with no supply cap to keep paying for mining security.The security reading is contested: security in practice depends on how much hashrate Grin attracts, and a community node operator's report on 7 and 8 November 2020 recorded three reorganizations of 23 to 43 blocks in which payments were reversed after 9 to 18 confirmations. Pruning keeps chain storage small, which helps home nodes; that is not the same as more transaction capacity. Privacy is a separate design goal, not a trilemma corner.
- Full node at home
- Practical at home 561116192728No official RAM, disk or bandwidth figure was found. The design keeps nodes light: blocks are capped at about 1.5 MB (per a code comment), spent outputs are pruned, and new nodes sync current state in verified segments. On 27 September 2026 the grincoin.org explorer reported about 334,000 unspent outputs (about 236 MB) and 6.4 million kernels (about 726 MB), which is provider data, not a requirement. GRIM can run a local node; Grin++ says its node syncs in minutes, an unmeasured project claim.
- Throughput claims
- No classified figure recorded
Scaling layers
- Mimblewimble payment channels (design only) · Payment channels, research 10121315
Design stage only. Robust channels need relative lock heights for a revocable close; Grin defines these as No Recent Duplicate kernels, but the reference node keeps them disabled on mainnet and rejects such kernels there. No channel software for Grin was found.
Capabilities
| Capability | How it is provided | Notes and sources |
|---|---|---|
| Account abstraction | Structured assessment pending | Not yet assessed for any chain. |
| Atomic swaps | Unknown | Not yet assessed under the current definitions; Grin's contracts document describes cross-chain swaps in which an adapted Schnorr signature reveals the secret that unlocks the other chain's side, with a jointly built refund locked to a block height, and height-locked kernels are valid on mainnet. These are building blocks: no maintained swap tool was found, forum members describe earlier work as stalled, and a Monero-to-Grin swap tool called Janus was shown only as a demo video in July 2026, with no public code or release. 10122930 |
| Authenticated data publication | Unknown | Not yet assessed under the current definitions; the earlier review found no data publication feature (Grin carries only private value transfers) but did not verify absence. 8 |
| Light clients | Built into the protocolLimited scope | Protocol, limited: every header records the chain's total difficulty, and a new node can fully verify current state from headers, the unspent outputs and all kernels without downloading spent history, fetched in parallel segments (PIBD) with proofs against the header. The limit: there is no light client for wallets; phone wallets either run a node or trust a remote one. 56916 |
| Native staking or delegation | Structured assessment pending | Not yet assessed for any chain. |
| On-chain governance | Structured assessment pending | Not yet assessed for any chain. |
| Parallel execution | Structured assessment pending | Not yet assessed for any chain. |
| Payment or state channels | None found Earlier definition | Payment channels exist only as a design: the relative lock heights they need are disabled on mainnet in the reference node, and no channel software was found. 1315 |
| Programmable spending | Partial (layer not stated) Earlier definition | No script language or contract state. Spend conditions are limited to what kernels and signatures express: absolute lock heights, and multi-party outputs built from aggregated keys as described in Grin's contracts document. Relative lock heights are disabled on mainnet. 101213 |
| Protocol-verified messaging | Structured assessment pending | Not yet assessed for any chain. |
| Reversible transfers or recovery | Unknown | Not yet assessed under the current definitions; jointly held outputs and absolute lock heights are building blocks with which parties can build escrow or refund-after-a-height paths, as Grin's contracts document describes, but the relative lock heights that delayed-recovery or revocable designs rely on are disabled on mainnet in the reference node, and no live implementation is cited. The protocol cannot reverse a confirmed payment. 101315 |
| Rollups | Unknown | No source was cited for absence, so the rule that absence needs a source makes this unknown. Earlier finding: no rollup anchored to Grin was found in reviewed sources; absence was not exhaustively verified. |
| Shielded transfers | Structured assessment pending | Not yet assessed for any chain. |
| Signed partial offers | Unknown | Not yet assessed under this row's current definition. |
Reading these values
- How this feature is provided
- Built into the protocol, core-team software or independent software says where a feature lives and who can change it. These are implementation layers, not quality: core-team software is not closer to the protocol than independent software.
- Structured assessment pending
- The shared review has not assessed this feature for any chain yet (Account abstraction, Native staking or delegation, On-chain governance, Parallel execution, Protocol-verified messaging and Shielded transfers). That does not mean it is absent, and a chain’s profile may already describe it.
- Unknown
- The review has not established this for this chain under the current definition; the note beside it says why. Unknown is not absent and not a low score. A feature reads “Not present” only when a source shows it is absent.
- Earlier definition
- Payment or state channels, Programmable spending and Rollups keep the earlier definition until the next fact-check. There, “Native” does not separate the protocol from core-team software, “Ecosystem software” does not say who publishes it, and “Partial” does not say which layer.
- Reading across rows
- The list of capabilities is incomplete. Do not read these rows as a chain leading or lagging overall.
Ecosystem & custody
| Product type | Status | Notes and sources |
|---|---|---|
| Automated market makers | None found | Grin has no contract layer or token registry to host an AMM. Grin's services page lists centralized exchanges and the peer-to-peer exchange Bisq instead; whether each still offers GRIN markets was not verified. 7 |
| Issuer-native stablecoins | None found | Grin transactions carry a single asset, GRIN; the protocol has no token issuance, so no native stablecoin can exist on it. 8 |
| Algorithmic stablecoins | None found | None: the protocol has no token issuance or contract layer to host one. 8 |
| Bridges | Unknown | The earlier note said absence was not verified, so the rule that absence needs a source makes this unknown. Earlier finding: no bridge or wrapped GRIN was found in Grin's docs or services list, and Grin cannot lock coins under script control, so any wrapped form would rely on a custodian. 7 |
| Block explorers | Thingrincoin.org | Grin's services page lists three mainnet explorers. At review only grincoin.org worked, serving a current block height of about 4.04 million with a block 35 seconds old; grinexplorer.net returned a server error and the grinminer explorer's domain did not resolve. By design no explorer can show amounts, addresses or balances. 471826 |
| Hardware wallets | Unknown | The earlier note said absence was not verified, so the rule that absence needs a source makes this unknown. Earlier finding (see custody rows): Trezor states it does not support Grin, and no working Ledger path was found (Ledger Wallet has no Grin entry and the catalogue's Grin app was last built in March 2023 for firmware since replaced), although Ledger has not stated that it does not support Grin. No other hardware wallet path was found. 2331 |
Hardware-wallet custody
| Device maker | Status | What users can and cannot do |
|---|---|---|
| Ledger | UnknownSame as native: Unknown | Cannot: Manage GRIN in Ledger Wallet (formerly Ledger Live), whose currency list has no Grin entry Cannot: Install a Grin app built for current Ledger firmware; the catalogue's last Grin build dates from March 2023 Cannot: Sign Grin transactions on a Ledger device through any wallet found in this reviewLedger support is left open rather than marked unsupported, because no Ledger statement that it does not support Grin was found (Ledger's Grin coin page returned not found), and the custody rule marks a coin unsupported only on a vendor statement. The evidence found points to no working path: Ledger's app catalogue still holds a Grin app (version 3.0.3) built from the community MimbleWimble Coin app's code, but its builds stop in March 2023 at firmware versions since replaced, while the MWC app for the separate MWC chain is built for current firmware. The app's current source builds only MWC. 6212231323334 |
| Trezor | None foundSame as native: No | Cannot: Use GRIN with a Trezor device; Trezor's Grin page says it does not currently support Grin 23 |
Public data
iKnow Blockchain has no public-data lookups for Grin yet. This is a limit of the service, not a statement about the network.
| Lookup | Status | What it covers and its limits |
|---|---|---|
| Address or account | Not available yet | Public-data lookups for this chain are not built yet. |
| Tokens and assets | Not available yet | Public-data lookups for this chain are not built yet. |
| NFTs | Not available yet | Public-data lookups for this chain are not built yet. |
| Transactions | Not available yet | Public-data lookups for this chain are not built yet. |
Sourced developments
Developments: Review overdue Reviewed Sep 27, 2026; next review was due Oct 7, 2026, 12:00 UTC.
Publication date · newest first
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Grin wallet 5.5.0 adds a built-in Tor client and mixing APIs
grin-wallet v5.5.0 integrates the Arti Tor client, exposes interfaces for the experimental mwixnet mixing service, resumes and speeds up output scanning, and fixes Slatepack address handling. It followed node v5.5.1 on 2026-08-11, which updated TLS and HTTP dependencies and switched the terminal interface backend.
- Implementation:shipped in wallet v5.5.0 and node v5.5.1
- Release:stable releases published 2026-08-11 and 2026-08-12
- Activation:no consensus change; takes effect as users upgrade
Sources: GitHub API (mimblewimble/grin-wallet) — Grin wallet release records (external site) · GitHub API (mimblewimble/grin-wallet) — Grin wallet commits between v5.4.1 and v5.5.0 (external site) · GitHub API (mimblewimble/grin) — Grin v5.5.1 release record (external site) · GitHub API (mimblewimble/grin) — Grin commits between v5.5.0 and v5.5.1 (external site)
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Mwixnet mixing service opened for community testing on testnet
A Grin developer reported deploying a public testnet route for mwixnet, with one swap server and one mixer running over Tor, and published a test guide while wallet and server compatibility work continued.
- Proposal:community test
- Implementation:testnet route deployed by a developer
- Release:not released for mainnet
- Activation:not active on mainnet as of 2026-09-27
Sources: Grin forum — Mwixnet community TEST (external site) · Grin developers — mimblewimble/mwixnet (external site) · Grin forum — Grin Development Progress Reports (external site)
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Grin node 5.5.0 fixes parallel sync peer handling
Grin v5.5.0 lists a fix to how the node picks and blocks peers during parallel state sync, and to terminal-interface startup and shutdown. The commit comparison also shows the node's database binding moving to a new library, IPv6 as the default listen address and validation of sync segment indices.
- Implementation:shipped in v5.5.0
- Release:stable release published 2026-06-16
- Activation:no consensus change; takes effect as nodes upgrade
Sources: GitHub API (mimblewimble/grin) — Grin v5.5.0 release record (external site) · GitHub API (mimblewimble/grin) — Grin commits between v5.4.1 and v5.5.0 (external site)
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Grin node 5.4.1 fixes parallel sync and peer handling
Grin v5.4.1 is a point release of the reference node published without notes. Its seven commits fix a loop that could leave parallel state sync stuck while requesting kernel segments, cap how many items the node will allocate when decoding sync segments from peers, stop treating newly learned peers as healthy before they are checked and mark peers that fail pings as defunct, and refresh the list of seed nodes a new node contacts first.
- Implementation:shipped in v5.4.1
- Release:stable release published 2026-06-11
- Activation:no consensus change; takes effect as nodes upgrade
Sources: Grin developers (mimblewimble/grin) — Grin v5.4.1 (external site) · GitHub API (mimblewimble/grin) — Grin commits between v5.4.0 and v5.4.1 (external site) · GitHub API (mimblewimble/grin) — PIBD sync stuck fixes (pull request 3822) (external site) · GitHub API (mimblewimble/grin) — More reliable peers check (pull request 3824) (external site) · GitHub API (mimblewimble/grin) — PIBD: bound segment decoding allocations (pull request 3850) (external site)
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Grin node 5.4.0 released, the first node release since 2024
Grin v5.4.0 was the first new reference-node version since v5.3.3 in September 2024 (a rebuild of 5.3.3 followed in November 2024). Its commits make long-overdue upgrades to the networking libraries (Tokio 1.x and Hyper 0.14), fix a case where fast state sync could stall, add a chain-type field to node status, allow running without the terminal interface, and publish Docker images for x86 and ARM.
- Implementation:shipped in v5.4.0
- Release:stable release published 2026-03-09
- Activation:no consensus change; takes effect as nodes upgrade
Sources: Grin developers (mimblewimble/grin) — Grin v5.4.0 (external site) · GitHub API (mimblewimble/grin) — Grin commits between v5.3.3 and v5.4.0 (external site)
Topics your AI can explain
Your AI can explain these topics for Grin through the connection, with sources.
Known gaps
What this profile's review did not establish:
- No throughput figure is listed; no primary-source rate was classified for this profile.
- No official RAM, disk, bandwidth or current chain-size figure for a Grin node was found; the home-node reading rests on design limits and wallet developers' claims.
- Current hashrate, pool concentration and the share of purpose-built mining hardware were not measured.
- The November 2020 reorganization depths and double-spends come from a community node operator's report; they were not checked against chain data here.
- Ledger's public supported-asset search page could not be read and its Grin coin page returned not found. Ledger support is left open because no Ledger statement of non-support was found; its app catalogue and open-source currency list show no working Grin path, and whether the old Grin app still installs on devices running superseded firmware was not tested.
- No maintained atomic-swap tool for Grin was verified; the swap row rests on a design document and a demo announcement.
- Two of the three explorers in Grin's services list were unreachable at review.
- The unspent-output and kernel sizes come from one explorer's own node and are not an official node requirement.
- Whether the exchanges listed in Grin's services page still list GRIN was not verified.
- The mwixnet mixing service is in community testing only and is not reflected in the privacy rows; this profile must be updated if it reaches mainnet.
Sources
Oldest dated source check: Source checked Sep 27, 2026 Next check due Oct 27, 2026.
- Grin (external site)
- Proof of Work (external site)
- Emission (external site)
- Privacy (external site)
- Scalability (external site)
- Wallets (external site)
- List of services (external site)
- Introduction to Mimblewimble and Grin (external site)
- Blockchain syncing (external site)
- Contracts (external site)
- core/src/consensus.rs (external site)
- core/src/core/transaction.rs (external site)
- src/bin/grin.rs (external site)
- RFC 0017: fix-fees (external site)
- RFC 0013: nrd-kernels (external site)
- RFC 0022: pibd-deployment (external site)
- Grin node releases (external site)
- Grincoin.org Grin explorer (external site)
- Grin++ (external site)
- GRIN 51% attack technical report - published (external site)
- Ledger-MimbleWimble-Coin (external site)
- Ledger-MimbleWimble-Coin Makefile (external site)
- Grin on Trezor (external site)
- chain/src/chain.rs (external site)
- GRIN REORG Attack - 2020/11/08 (external site)
- grincoin.org latest block height (external site)
- grincoin.org unspent output count and size (external site)
- grincoin.org kernel count and size (external site)
- The ever elusive atomic swap. Whats the current status? (external site)
- Janus: Monero<->Grin Atomic Swaps (external site)
- Ledger app catalogue entry: Grin (external site)
- Ledger app catalogue entry: MimbleWimble Coin (external site)
- app-mimblewimblecoin Makefile (external site)
- Ledger Wallet currency definitions (external site)
Report an error
Found something wrong or out of date? Reporting is free, and every chain goes through the same process. Published corrections appear in the public log.
Funding disclosure
Funding disclosures appear here when an upkeep arrangement exists, in the form “Upkeep funded by [name]; verdicts unaffected.” The funder ledger has not been published yet. Neutrality & funding