Fluidkey
1 known investors
Fluidkey is a self-custodial onchain financial platform where users receive, hold, and spend funds through global bank-transfer accounts (IBAN, ACH, wire), earn automatic yield, and access over 400 crypto assets. It uses stealth addresses to keep users' onchain activity private and is aimed at individuals managing their financial life on-chain.
Also known as FluidKey
Founders & leadership
Investors Β· 1
Company profile
researched Aug 2026Fluidkey is a self-custodial interface for managing funds onchain, built on Safe smart contract accounts and the ERC-5564 stealth address standard and layered on top of a user's existing wallet. Each incoming payment is routed to a newly generated stealth address, while all balances are aggregated into a single dashboard so the experience resembles a conventional wallet. Users receive a static, human-readable identifier of the form username.fkey.eth / username.fkey.id, which resolves via an ENS offchain resolver to a fresh stealth address on every query. When sending, Fluidkey selects the stealth address or combination of addresses that covers the payment amount, and the recipient sees a single incoming transfer.
Alongside private receiving, the product offers fiat rails and yield. Through Bridge (the payments-infrastructure company acquired by Stripe), users can obtain USD or EUR account details in their own name supporting ACH, SEPA and wire transfers, with identity verification handled by Persona and US dollar accounts issued by Bridge with Lead Bank; Fluidkey states bank KYC typically takes under five minutes. Deposited USDC can be sent by ACH to US banks or brokers, with Interactive Brokers and Charles Schwab named in the documentation. An Auto-Earn feature deploys stablecoins into whitelisted, audited DeFi protocols while keeping funds spendable, with an Optimized mode using Summer.fi pools, a Core mode using Gauntlet to allocate across Morpho and Aave, and an off setting; yield is variable and Fluidkey retains 10% of it. The company also markets access to more than 400 tokenized assets and issues a Fluidkey Score, a non-transferable ERC-20 on Base recording activity such as balance, referrals and Auto-Earn deposits, which determines the monthly fee-free on/off-ramp allowance. Transaction records can be exported to major tax software.
Accounts are available on seven EVM chains β Ethereum, Arbitrum, Base, Polygon, Optimism, Gnosis and BSC β and, via a Near Intents integration, users can receive BTC, USDC and USDT from ten further chains (Bitcoin, Tron, Solana, Binance, Near, Avalanche, Ton, Sui, Stellar, Monad), settled as USDC on Base. Bank withdrawals can currently be initiated from stablecoins on Base, Ethereum, Arbitrum and Polygon.
Founding story
The concept of connecting stealth addresses to smart accounts was originally shaped by co-founder Moritz, who posted the idea on Farcaster. Antonio, previously a freelance Solidity developer for three years and before that a Web2 cloud native architect, read the post and reached out; both were in Paris ahead of an ETHGlobal hackathon and built the project during the event, which became Fluidkey.
Business model
Fluidkey operates a consumer-facing wallet interface monetized through transaction and balance-based fees rather than custody of assets: the company holds only view access to user accounts, while spending keys remain with the user.
Fee-based. Bank on/off-ramp activity above a monthly free allowance (set by the user's Fluidkey Score: $3,000/month below a score of 10,000 and $20,000/month at or above it) is charged a flat 0.3%; Fedwire transfers under $10,000 carry a fixed $25 fee; USDT on Ethereum mainnet carries a 0.1% conversion fee with a $20 minimum. Fluidkey also takes 10% of yield generated by the Auto-Earn feature.
Traction
The website reports more than 28,000 users and over $1 billion in cumulative transfers. In a July 2024 interview, the co-founder said the company was processing close to $500,000 in transactions per month, supported five chains, and had recently enabled use of any ERC-20 token; support has since expanded to seven EVM chains plus ten additional chains via Near Intents.
Latest developments
Current offering includes global bank accounts (IBAN/ACH/wire) via Bridge with Lead Bank, automatic yield through Summer.fi, Gauntlet, Morpho and Aave routes, access to more than 400 tokenized assets, the Fluidkey Score on Base, and cross-chain deposits via Near Intents settled as USDC on Base.
βΈFull profile β market position, technology, go-to-market, geography, history, risks & controversies
Market position
Positioned as a privacy layer and financial interface on top of existing wallets rather than a replacement wallet, combining private receiving, fiat on/off-ramps and automated stablecoin yield in one application.
The approach gives users a fresh address per incoming payment without manual address management, combining stealth-address unlinkability with smart-account UX benefits such as gas sponsorship. Because funds are not mixed with other users', Fluidkey states there is no risk of commingling with illicit funds; the company also notes stealth addresses provide unlinkability but not untraceability, so fund history remains disclosable to tax authorities or auditors. Custody design allows fund access even if Fluidkey ceases to operate.
Technology
On sign-in, a user signs a key generation message with an existing Ethereum account; the signature derives a private spending key (controls funds and signs transactions) and a private viewing key (retrieves and views transactions). The key pair never leaves the client and is not stored locally. The user shares a BIP-32 derived node of the viewing key (path m/5564'/N', referencing ERC-5564; N is currently 0) so Fluidkey can generate addresses and index incoming funds. Stealth accounts are 1/1 Safe smart accounts, each controlled by a stealth EOA derived pseudo-randomly from a new leaf of the shared viewing key node, using a derivation path such as m/5564'/0'/8'/0'/0'/p'/n' with coinTypes following ENSIP-11; the current coinType corresponds to chainId 0 so addresses are valid across supported EVM chains. Addresses are counterfactually predicted and the underlying contract is only deployed at withdrawal. Because derivation is deterministic and replayable, users can recover funds independently of Fluidkey. Static ENS names resolve through an offchain resolver (EIP-3668 dynamic resolution) to a new stealth address per query. Core cryptographic functions are released as an open-source kit. Infrastructure includes real-time block notifications and data streams from QuickNode for tracking the thousands of addresses generated per user.
Go-to-market
Self-serve sign-up through the web and mobile apps using an existing wallet or social/email login, supported by public documentation, a referral component within the Fluidkey Score, and developer/infrastructure partner content.
Individuals managing personal funds onchain, including freelancers and DAO members earning directly on-chain, users receiving salary, client or investor payments, and donation or crowdfunding recipients. Compatible wallets include MetaMask, Coinbase Wallet, Rainbow, Dawn and any WalletConnect-compatible EOA or MPC wallet, plus sign-in with Farcaster, Google or email; hardware wallets are supported while multisigs are not.
Geography
Headquartered in Switzerland, cited by the company for its user data and privacy protection rights. The product is distributed globally via iOS, Android and web, with USD and EUR bank rails (ACH, SEPA, wire) and support for multiple blockchains.
History
Fluidkey began as a hackathon project at an ETHGlobal event in Paris. An alpha version launched in March 2024, followed by a more stable release in June 2024 after the core cryptography was audited by Dedaub. The team initially focused on the underlying technology before prioritizing user experience. The product later added support for any ERC-20 token, expanded from five to seven EVM chains, integrated Near Intents for cross-chain deposits, and introduced fiat bank accounts via Bridge, Auto-Earn yield and tokenized asset access.
Risks & controversies
Stealth addresses provide unlinkability but do not break traceability, so transaction history leading to a stealth address remains traceable. Auto-Earn yield is variable market yield rather than a fixed rate and is not guaranteed; funds are restricted to whitelisted audited DeFi protocols, though audits reduce rather than eliminate risk. Third-party commentary notes the service may be less suitable for very large cross-border flows due to compliance review and cost, and that bank features depend on external providers (Bridge, Persona, Lead Bank). Bank withdrawals are limited to stablecoins on a subset of supported chains.
Compiled by commissioned research from 8 cited public sources β announcements, filings, and press listed under research sources below.
Key figures
latest reportedCompany-reported or press-reported figures, each dated to when it was claimed β not independently audited.
Timeline Β· 7
launches, deals, and filingsFluidkey provides USD and EUR account details in the user's own name via Bridge, with US dollar accounts issued by Bridge with Lead Bank and identity verification by Persona.
Auto-Earn deploys stablecoins into whitelisted DeFi protocols with an Optimized mode via Summer.fi pools and a Core mode using Gauntlet to allocate across Morpho and Aave.
Users can receive BTC, USDC and USDT from ten additional chains including Bitcoin, Tron, Solana, Binance, Near, Avalanche, Ton, Sui, Stellar and Monad, deposited as USDC on Base.
Fluidkey relies on QuickNode real-time block notifications and Streams data ingestion to track the thousands of stealth addresses generated per user.
Fluidkey enabled use of any ERC-20 token and supported five chains, with swapping and bridging possible without holding native tokens.
A more stable version launched in June 2024 following an audit of the core cryptography by Dedaub.
Dated company events from announcements, filings, and press; legal rows summarize public dockets and regulator releases.
βΈResearch sources Β· 8
primary sources listed
- Fluidkeyfluidkey.com Β· web
8 public sources were cited for this profile; the first-party ones are listed here.
Frequently asked questions
- What does Fluidkey do?
- Swiss self-custodial onchain wallet interface using stealth addresses, with global bank accounts and automatic stablecoin yield.
- Who founded Fluidkey?
- Fluidkey was founded by Antonio Seveso.
- Who are Fluidkey's investors?
- Fluidkey's investors include Alliance DAO (ex DeFi Alliance).