Legal

Risk disclosures

Last updated October 23, 2026 (draft)

Draft pending legal review

This text is a plain-English draft written while UMBR runs on testnets. It has not been reviewed by a lawyer and may change before UMBR handles real money. Questions: @umbrtrade on X.

Please read this before using UMBR. It lists the main ways things can go wrong. It is not exhaustive.

1. Testnet software

UMBR runs on Robinhood Chain testnet and Tempo Moderato testnet with test tokens that have no value. It is early software. Features may be incomplete, change or disappear, and test contracts may be redeployed, leaving old test balances behind. No mainnet pool is configured.

2. You can lose access

UMBR is self-custodial. If you lose your wallet keys, your device, or the private notes stored on it without a backup, nobody can restore them, including us. Confirmed transactions generally cannot be reversed, and a payment sent to the wrong recipient or a payment link shared with the wrong person cannot be recalled.

3. Smart contracts and cryptography

The pool contracts and zero-knowledge circuits may contain bugs. The testnet proving keys come from a development setup rather than a public ceremony, and no independent security review has been completed. Cryptographic assumptions that are believed sound today could be weakened in the future.

4. Privacy has limits

UMBR reduces what the public can learn about you. It does not make you invisible:

shielding and unshielding are public, including addresses, assets and amounts;
a small or new pool offers a small crowd, so links between deposits and withdrawals can be easier to guess;
timing, matching amounts and reused addresses can reveal patterns;
malware on your device, or a proof you share, can reveal more than you intend.

The privacy model and threat model explain these limits in detail.

5. Token issuers and stablecoins

Stablecoins are issued by third parties. An issuer can block addresses, freeze tokens, or apply other policies, including to tokens held by a pool. A stablecoin can lose its peg or be discontinued. UMBR does not control or guarantee any token.

6. Networks and third parties

UMBR depends on blockchains, validators, RPC providers, browser wallets and hosting it does not control. Any of them can be congested, halted, reorganised, attacked or changed. Network fees vary, and on Tempo they are paid in a stablecoin.

7. The relayer

A relayer is optional. It can delay or refuse to submit a transaction but cannot change its amount or recipient. It sees the network address your request came from. If it is unavailable, you can submit from your own wallet, which links that transaction to your address.