Where your money goes when you join a vault
A vault is a group on Fexr linked to a smart contract or a DeFi protocol. Your wallet signs every deposit and withdrawal. Fexr prepares each transaction and shows the group what the chain recorded. We never hold your funds or a key that can move them.
- Fexr prepares itFexr
- Your wallet signs itYou
- The chain runs itChain
- Fexr reads it backFexr
Example transactions. The order of steps is how every vault transaction works.
Where the money sits, by vault type
Each vault is set to one type when it is created. The type decides where a deposit goes. In every case the transaction leaves from your wallet, and Fexr is never a stop along the way.
| Vault type | Where a deposit goes | What you hold afterwards |
|---|---|---|
| Aave and Spark | From your wallet straight into the lending pool, recorded in your name. | The pool's receipt token, such as aUSDC, in your wallet |
| Compound | From your wallet into the Compound market. | A Compound balance owned by your wallet |
| Lido | ETH staked from your wallet. | stETH, in your wallet |
| Group pools | Into the vault's own contract: a shared pool, a savings pool with reward tiers, a charity-yield pool or a standard tokenized vault. | A balance in that contract, withdrawn under its rules |
| Fexr yield vault Not live | Fexr's own vault contract. Written and tested, but not deployed and not yet reviewed by an outside auditor. Status below. | Nothing yet |
If Fexr went away, your position would still be in the protocol or the contract, and your wallet could withdraw it directly. What would go with us is the group layer: membership, claims, confirmations and the shared record.
How a deposit works
Withdrawals follow the same steps in reverse. Only step 3 can move money, and only your wallet can do it.
- 1YouChoose an amountIn a vault you are a member of.
- 2FexrPrepare the transactionWhich contract, which token, how much.
- 3Your walletSign itThe only step that moves money.
- 4The chainRun itOn the contract's terms, which Fexr can't edit.
- 5FexrRead it backFrom the contract's own events.
Your balance on Fexr comes from the chain. We read the contract's events (deposits, withdrawals, yield harvested, reward tiers unlocked) and show those. Nobody types a balance in. An older one-step deposit endpoint that skipped your signature now refuses every request.
Signing in to Fexr and signing a transaction are separate
Your Fexr login lets you take part in the group. Only your wallet can move money. Losing one doesn't hand over the other.
Signing in, through Fexr Auth
Fexr Auth is our sign-in service. Your session is tied to a key that stays on your device. Every request the app sends carries a fresh signature from it, which expires within a minute and works once, so a copied session token is refused.
- Join or invite people
- Confirm or dispute a claim
- Request or approve a payout
Moving money, with your wallet
Deposits and withdrawals need a signature from the wallet that owns the funds. Fexr doesn't hold that key, so there is nothing for us to sign with and nothing for anyone to pressure us into using.
- Deposit into a vault
- Withdraw from a vault
- Remove a protocol approval
The group rules Fexr enforces
A contract can hold money, but it can't tell whether someone did the work they say they did. These rules cover the people side, and each one keeps a named record.
Nothing settles on a timer. A claim nobody confirms stays open, a payout nobody answers stays unpaid, and a disputed claim keeps its dispute on the record.
The Fexr yield vault: what's done and what isn't
Not deployed Β· no outside audit yetWe have written our own vault contract that puts a group's stablecoins into Aave. It isn't live on any network, and nobody outside Fexr has reviewed it. Until both happen, vaults use the established protocols and group pools in the table above. This is the work done to get it ready for review.
- Built on OpenZeppelin's standard codeThe vault accounting (the ERC-4626 tokenized-vault standard), the protection against re-entry attacks and the token transfers all use OpenZeppelin's libraries, which most audited contracts rely on.
- Protected against the first-depositor attackIn a naive vault, the first person to deposit can skew the share price against everyone after them. Here the share price comes from tracked positions, not from the contract's raw balance, so sending tokens straight to the contract can't move it.
- The Aave code is tested with random sequencesThe shared Aave code runs about 128,000 random deposits, withdrawals and yield updates per test run, checking that no value goes missing beyond a few units of rounding.
- The operator can do one thingThe operator role can only pull funds out of Aave back into plain stablecoins. It can't redirect money, change terms or block deposits and withdrawals. If Aave reports the market unhealthy, anyone can trigger that pull-out.
- A written threat modelWhat the contract trusts, what could go wrong and why each defence works are written down for the auditor.
What this doesn't protect you from
Common questions
What does a vault cost?
Nothing. Creating and running a vault is free. You pay network gas on your own deposits and withdrawals, and the protocol a vault uses may charge its own fees.
Where is my money, actually?
It depends on the vault type. For Aave, Spark, Compound and Lido it sits in that protocol, in your wallet's name. For group pools it sits in the vault's contract. It is never in a Fexr account.
Can Fexr move my money?
No. We prepare transactions, your wallet signs them and we record the result. We don't hold a key that could sign without you.
Can whoever started the vault take the money?
Paying anyone from the group's funds is a request with an amount and a reason that the group can see, and the contract's own terms still apply. Starting a vault doesn't come with a private way out.
What if a member lies about the work they did?
Other members dispute the claim, and it never reaches the number of confirmations it needs. The dispute stays on the record.
Where is the technical detail?
The API documentation covers the prepare and confirm calls behind every deposit. What a vault is covers the treasury, decisions and work.
Open a vault
Creating a vault is free. Pick its type, invite your group and set how many confirmations a claim needs.
- Vaults β what a vault is and what groups use it for
- The wallet β where you sign deposits and withdrawals
- Agentic safety β what a trading agent can do with your account
- Common questions