Category: privacy-preserving smart-account wallet / stealth-address wallet-control-plane / self-custodial bank-transfer and yield integration / recovery and security tooling
Summary: Fluidkey is better cataloged as a privacy-preserving wallet-control plane than as a simple wallet app. Its primary-source surface combines stealth Safe smart accounts, an open-source stealth-account kit, self-custodial recovery and backup flows, KYC-gated global bank-transfer rails that settle into self-custodial USDC, an auto-earn layer routed into Morpho and Aave vaults, and optional trail-hiding flows layered on top of stealth addresses. That combination makes Fluidkey look like a programmable privacy-and-finance operating stack for EVM users rather than only a consumer wallet.
What it does:
Uses stealth Safe smart accounts and counterfactual address generation so users can receive funds at privacy-preserving addresses without deploying each account up front
Derives user spending and viewing keys client-side from a signed key-generation message, with an open-source kit documenting and implementing the core cryptographic functions
Offers self-custodial account recovery through long-term login choice, cloud or local encrypted backups, optional private-key export, and spend-limit / multi-factor controls for larger transfers
Provides bank-transfer rails for USD and EUR through Bridge so incoming transfers can settle as USDC into the user’s self-custodial account, with KYC handled through the partner flow
Routes supported balances into auto-earn strategies using Morpho and Aave vaults, with the Fluidkey earn module audited by Ackee
Adds advanced privacy tooling such as Hide Trail, which uses Houdini Swap private-mode routing plus Fluidkey stealth addresses to reduce onchain linkability
Key claims:
The homepage says Fluidkey has processed more than $740,000,000 in transfer volume and generated more than 1,000,000 privacy-preserving addresses
The main docs page describes Fluidkey as a financial home where users can receive, grow, and spend funds with global accounts and instant yield
The account-setup docs say Fluidkey is self-custodial, that the app can never touch user funds, and that web keys are generated through a Privy embedded wallet while mobile keys are generated on-device and secured by the secure enclave
The technical walkthrough says Fluidkey uses 1/1 Safe smart accounts as stealth accounts, derives stealth signers from a viewing-key node, counterfactually predicts stealth-account addresses, and resolves username.fkey.id / username.fkey.eth to a fresh stealth address on each query
The bank-transfer docs say Bridge powers USD and EUR transfers and that incoming transfers are automatically deposited as USDC into a self-custodial Fluidkey account in a privacy-preserving manner
The auto-earn docs say the default profile routes balances into selected Morpho and Aave vaults and that the Fluidkey earn module was audited by Ackee
The advanced-privacy docs say Hide Trail is powered by Houdini Swap private mode and, when combined with Fluidkey stealth addresses, aims to make funds both untraceable and unlinkable onchain
The open-source stealth-account-kit repo says anyone can independently generate and recover stealth smart accounts and related funds
Whitepaper: No canonical Fluidkey whitepaper or litepaper surfaced in this pass. The clearest current source of truth was the official site, documentation set, privacy policy, technical walkthrough, and open-source stealth-account-kit repository; see ../whitepapers/fluidkey-primary-sources-2026-05-01.md.