# Fuyu

> Guides for Fuyu payments and DeFi, with SDK examples, contract references and setup instructions.

## Documentation

- [Connect to Fuyu](https://docs.fuyu.xyz/quickstart/connect): Open a private account, connect a wallet and check which approvals you need.
- [Get Funds](https://docs.fuyu.xyz/quickstart/get-funds): Deposit supported assets from a wallet or receive them through a Portal.
- [Send Your First Payment](https://docs.fuyu.xyz/quickstart/first-payment): Send a private payment and check the recipient's note and your change.
- [Networks & Environments](https://docs.fuyu.xyz/quickstart/networks): Choose a network, connect your wallet and check which Fuyu deployment you're using.
- [Use the Sepolia Testnet](https://docs.fuyu.xyz/quickstart/testnet): Get test funds, check your Sepolia deployment and send a private payment.
- [Passkeys and backup access](https://docs.fuyu.xyz/quickstart/passkeys): Add a second passkey, test it, and remove a lost credential without leaving earlier funds exposed.
- [Build on Fuyu](https://docs.fuyu.xyz/build): Add private payments, asset operations and recovery to your application.
- [Private Payments](https://docs.fuyu.xyz/build/private-payments): Pay a private receiving address and return any remaining value as change.
- [Payment Links](https://docs.fuyu.xyz/build/payment-links): Get paid from an external wallet or send a claim link to an unregistered recipient.
- [Batch Payments](https://docs.fuyu.xyz/build/batch-payments): Pay several recipients or combine small notes in one router transaction.
- [Asset Operations](https://docs.fuyu.xyz/build/asset-operations): Swap assets or enter vaults through approved routes, then recover the output in private notes.
- [Swaps](https://docs.fuyu.xyz/build/swaps): Use an approved Uniswap route and receive the returned tokens as a private note.
- [Earn & Vault Positions](https://docs.fuyu.xyz/build/earn): Supply assets to a vault, track your private shares and use its redemption path.
- [Withdrawals & Exits](https://docs.fuyu.xyz/build/withdrawals): Withdraw to a public wallet and recover any private change after confirmation.
- [Migrate to Fuyu](https://docs.fuyu.xyz/build/migration): Withdraw from another privacy protocol into a new Fuyu note on the same chain.
- [Multi-step Action Plans](https://docs.fuyu.xyz/build/action-plans): Combine approved swap and vault steps into one action with a final output minimum.
- [Selective Disclosure](https://docs.fuyu.xyz/build/disclosure): Prove a supported fact about your account without sharing its private history.
- [Account & Payment Recovery](https://docs.fuyu.xyz/build/recovery): Reopen your account or finish an interrupted payment using its saved authorization.
- [Safe Treasuries](https://docs.fuyu.xyz/build/safe-treasury): Use private notes that also require approval from your Safe.
- [Fuyu features](https://docs.fuyu.xyz/build/features): Find the guides for account setup, payments, DeFi, approvals and recovery.
- [Receiving names and addresses](https://docs.fuyu.xyz/build/receiving): Choose a private address, name, registered wallet address or deposit portal for your payer.
- [Pay wallets with claim links](https://docs.fuyu.xyz/build/claim-links): Send to someone without a Fuyu account, set a claim deadline and recover a claim that was interrupted.
- [History and reconciliation](https://docs.fuyu.xyz/build/history): Read account activity, check pending operations and understand what a history export contains.
- [Token balances and USD values](https://docs.fuyu.xyz/build/balances): Keep token amounts precise, separate checking funds and show USD estimates without hiding missing prices.
- [Disclosure consent and policies](https://docs.fuyu.xyz/build/disclosure-grants): Review an audit request, share a supported proof and understand what policy grants can do.
- [Spending wallets and Safe approvals](https://docs.fuyu.xyz/build/spending-approvals): Set up wallet B or Safe approvals and resume an operation without changing what was signed.
- [Encrypted recovery files](https://docs.fuyu.xyz/build/recovery-files): Save history and pending operations, restore them on another device and handle backup conflicts.
- [Gas sponsorship and fee reviews](https://docs.fuyu.xyz/build/gas-sponsorship): See who pays gas, which operations are sponsored and how fees affect a public payout.
- [Integrate Fuyu](https://docs.fuyu.xyz/integrate): Add funded payment rails and service accounting to your application.
- [Payment Sessions](https://docs.fuyu.xyz/integrate/payment-sessions): Buy service credit in increments and sign each resource request.
- [Streaming & Usage Billing](https://docs.fuyu.xyz/integrate/streaming): Bill a stream in segments and settle its purchases periodically.
- [Subscriptions](https://docs.fuyu.xyz/integrate/subscriptions): Charge prepaid periods and check whether the current period has been paid.
- [Authorization & Capture](https://docs.fuyu.xyz/integrate/authorization): Reserve a spending ceiling, then capture the amount the merchant charges.
- [Settlement & Revenue Sharing](https://docs.fuyu.xyz/integrate/settlement): Claim earned payments onchain and distribute them to the configured beneficiaries.
- [Author an Adapter](https://docs.fuyu.xyz/integrate/adapters): Write a Pool adapter and submit its route for publisher review.
- [DeFi Integration](https://docs.fuyu.xyz/integrate/defi): Connect swaps, vaults and settled payments to private notes. Start with the route, then handle quotes, execution and recovery.
- [ERC-4626 Vaults](https://docs.fuyu.xyz/integrate/erc4626): Add a synchronous vault: describe its shares, check its dependencies, register supply and redeem, and keep a share withdrawal path.
- [Aave V3 Stata](https://docs.fuyu.xyz/integrate/aave): Supply or redeem Aave static shares using the USDC fork route or the Sepolia WETH/native-ETH manifests.
- [Morpho V1 Vaults](https://docs.fuyu.xyz/integrate/morpho): Supply USDC to the Steakhouse V1 fork vault, account for 18-decimal shares and handle redemption or direct share withdrawal.
- [Dolomite dUSDC](https://docs.fuyu.xyz/integrate/dolomite): Use dUSDC shares for the USDC market-2 route. Check wrapper implementations, receiver permissions and available cash before execution.
- [Uniswap V3](https://docs.fuyu.xyz/integrate/uniswap): Swap USDC and WETH through one adapter per direction. Set the output floor, check the pool and recover the final private note.
- [Asynchronous Redemption](https://docs.fuyu.xyz/integrate/async-redemption): Turn a pending vault redemption into private tickets, then claim harvested assets or refund cancelled shares.
- [Tokenized Assets](https://docs.fuyu.xyz/integrate/tokenized-assets): Check token transfers, issuer permissions and trading liquidity before adding custody or a swap route.
- [Payment Credits & DeFi](https://docs.fuyu.xyz/integrate/payment-modules): Redeem settled payment credits for their backing asset and recover the payout as a private note.
- [Tools & SDKs](https://docs.fuyu.xyz/tools): Find the payment SDK, proof tools and independent audit verifier in the protocol checkout.
- [Payment SDK](https://docs.fuyu.xyz/tools/payment-sdk): Load the SDK from the protocol checkout and set up its payment ledgers.
- [Fuyu Policy Language](https://docs.fuyu.xyz/tools/fpl): Write account-history questions and check which evidence their answers need.
- [Independent Verifier](https://docs.fuyu.xyz/tools/verifier): Verify an exported audit answer against your own finalized chain history.
- [Contract Testing](https://docs.fuyu.xyz/tools/contract-testing): Run Solidity tests, choose the suites for your change and reproduce contract artifacts.
- [Fuyu API](https://docs.fuyu.xyz/api): Read deployment configuration, submit prepared proofs and track payment state.
- [SessionManager Reference](https://docs.fuyu.xyz/api/session-manager): Prepare purchases, accept resource requests and recover settlement after a restart.
- [Signed Request Reference](https://docs.fuyu.xyz/api/session-requests): Sign the resource ID, content, price and deadline separately from a purchase voucher.
- [Errors & Recovery](https://docs.fuyu.xyz/api/errors): Handle SDK errors and check whether the original operation reached the chain.
- [Fuyu Protocol](https://docs.fuyu.xyz/protocol): Learn how the Pool stores private notes and executes spends and external actions.
- [Notes & Commitments](https://docs.fuyu.xyz/protocol/notes): Understand note openings, nullifiers and the point where outputs become spendable.
- [Privacy & Trust Boundaries](https://docs.fuyu.xyz/protocol/privacy): See which note details stay private and what observers can still learn.
- [Controllers & Authorization](https://docs.fuyu.xyz/protocol/controllers): Require a wallet or claim controller to approve spending a note.
- [Fees & Gas](https://docs.fuyu.xyz/protocol/fees): Read the relay fee policy and see who pays gas for each funding and payment path.
- [Smart Contracts](https://docs.fuyu.xyz/protocol/contracts): Choose a contract for funding, private transfers, merchant payments or recovery.
- [ActionPool](https://docs.fuyu.xyz/protocol/contracts/pool): Fund private notes, spend them with proofs, and settle external actions through ActionPool.
- [Deposit Portals](https://docs.fuyu.xyz/protocol/contracts/portals): Receive ERC-20 transfers at a Portal, then credit private notes or recover uncredited tokens.
- [Controllers and Claim Links](https://docs.fuyu.xyz/protocol/contracts/controllers): Require wallet approval for private spends and set recipient and refund windows for claim links.
- [Payment Rails](https://docs.fuyu.xyz/protocol/contracts/payment-rails): Use prepaid sessions, authorization holds and subscriptions, with fixed funding and payout terms.
- [Routers and Adapters](https://docs.fuyu.xyz/protocol/contracts/routers-adapters): Batch private spends and run fixed swap, yield or payment-credit operations through the Pool.
- [Policies and Governance](https://docs.fuyu.xyz/protocol/contracts/policies): Manage source policies, delayed configuration changes and coverage renewal.
- [Accounts and Receiving Directory](https://docs.fuyu.xyz/protocol/contracts/accounts): Store encrypted account records and publish receiving descriptors with wallet approval.
- [Earn Contracts](https://docs.fuyu.xyz/protocol/contracts/earn): Use Flex shares, Term shares and withdrawal tickets through the Earn vault and Pool adapter.
- [Migration Receivers](https://docs.fuyu.xyz/protocol/contracts/migration): Receive a source withdrawal, credit a fixed private account and recover uncredited funds after a deadline.
- [Run Infrastructure](https://docs.fuyu.xyz/infrastructure): Run deployment, relay and recovery services without holding private account secrets.
- [Deployments & Artifact Pins](https://docs.fuyu.xyz/infrastructure/deployment): Deploy the contracts and record the hashes needed to authenticate them.
- [Relayers & Runtime](https://docs.fuyu.xyz/infrastructure/relayer): Submit prepared proofs, check transaction status and finish pending settlement.
- [Service-independent Recovery](https://docs.fuyu.xyz/infrastructure/recovery): Keep the app, proof files and deployment data users need during a service outage.
- [Contract Addresses](https://docs.fuyu.xyz/infrastructure/contract-addresses): Find each Sepolia contract, what it does and which Fuyu deployment uses it.
- [Proof Artifacts & Verification Keys](https://docs.fuyu.xyz/infrastructure/proof-artifacts): Download, host and check the files used to prove private spends and holder disclosures.
- [Local Development & Testing](https://docs.fuyu.xyz/infrastructure/local-development): Start a private fork, run the API and app, and test against the contracts from your own build.

Full documentation: https://docs.fuyu.xyz/llms-full.txt

SDK examples use the protocol repository's SDK. See Tools & SDKs for installation. Use the endpoints and contract addresses for your chosen deployment.