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Umi Signer is your on-chain security layer. It is a smart contract on Sui that holds your signing capabilities and enforces the rules you set - without trusting anyone.

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What is Umi Signer

When you create a Umi account, a Umi Signer object is created on Sui. This object:
  • Holds your dWallet capabilities (the ability to sign on each chain)
  • Enforces policies you define
  • Authorizes DApps and agents you approve
  • Executes rules automatically, trustlessly, on-chain
Think of it as a programmable vault for your signing power. You set the rules, and the blockchain enforces them. No human in the loop. No trust required.

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Why this matters

Before Umi Signer, you had two options:
  1. Full control - You approve every transaction manually. Secure but not automated.
  2. Give up control - Let a service or bot hold your keys. Automated but risky.
Umi Signer gives you a third option: programmable control. You define exactly what can happen, and the blockchain enforces it. Automation without sacrificing security. This lets Umi recreate features that were only possible on centralized exchanges - but without giving up your keys or trusting a company.

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Policies

Policies are rules that govern what your Umi Signer allows. They are enforced on-chain before any signature is produced. Spending limits Set maximum amounts per transaction or per time period.
  • No single transaction over $10,000
  • Maximum $50,000 per day
  • Maximum $200,000 per month
Address allowlists Restrict where funds can be sent.
  • Only send to these 5 addresses
  • Only interact with these verified contracts
  • Block all transfers to new addresses unless I approve
DApp authorizations Control which applications can request signatures.
  • Allow Uniswap to swap tokens up to $1,000 per transaction
  • Allow my trading bot to trade within daily limits
  • Block all other DApps
Time-based rules Set conditions based on time.
  • Require 24-hour delay for withdrawals over $50,000
  • Only allow automated trades during market hours

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Beneficiary policies

This is where Umi Signer gets revolutionary. You can set up inheritance and recovery rules that execute automatically: Dead man’s switch If I do not sign any transaction for 365 days, transfer control to this beneficiary address. No lawyers. No probate. No trusting a company to honor your wishes. The rule is on-chain and executes automatically. Gradual transfer If I am inactive for 180 days, allow my beneficiary to withdraw up to 10% per month. Recovery backup If I am inactive for 90 days, this trusted friend can initiate a recovery process. These are not features a company provides - they are rules you set that the blockchain enforces. Even if Umi disappeared tomorrow, your policies would still execute.

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Authorizing agents

Umi Signer is how you give AI agents and automation tools the ability to sign on your behalf - safely. How it works:
  1. You create an authorization in your Umi Signer
  2. Define what the agent can do (chains, amounts, addresses, frequency)
  3. The agent gets scoped access to request signatures
  4. Umi Signer enforces the rules on every request
Example authorizations:
  • Trading bot can swap tokens on Ethereum, max $5,000 per trade, max $25,000 per day
  • Payment processor can send USDC to addresses on my payroll list, max $10,000 per transaction
  • Rebalancing agent can move funds between my own addresses on any chain
The agent never has your keys. It requests signatures, and Umi Signer decides whether to approve based on your policies.

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DApp sessions

When you connect to a DApp through the Umi extension, you can set session policies: One-time approval Approve this single transaction - standard wallet behavior. Session approval Allow this DApp to request swaps up to $500 for the next hour - no repeated popups while you are actively using the app. Standing authorization This DApp can always request signatures for transactions under $100 - for apps you use frequently and trust. You control the scope. The blockchain enforces it.

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Ownership and control

Your Umi Signer is a Sui object, and you control who owns it. zkLogin for simplicity By default, your zkLogin account (Google, Apple, Facebook, passkey) owns your Umi Signer. This gives you the streamlined experience - no seed phrases, no hardware devices, just log in and go. Hardware wallet for maximum security Want even more control? You can transfer your Umi Signer ownership caps to a hardware wallet (Ledger, etc.) or any other Sui wallet. Your hardware wallet becomes the ultimate authority over your signing policies. Multi-wallet authorization You can authorize multiple wallets to interact with your Umi Signer:
  • Your zkLogin for daily use
  • Your hardware wallet for high-value approvals
  • A trusted family member’s wallet for recovery
Transfer ownership anytime Moving your Umi Signer caps is just a Sui transaction. Transfer from zkLogin to hardware wallet when you are ready for maximum security. Or set up a multi-sig arrangement where both must approve major changes. Coming soon We are adding more login options:
  • Hardware wallet login (use your Ledger as your primary login)
  • Other Sui wallet login (use any existing Sui wallet)
  • Multi-factor setups (require both zkLogin and hardware wallet)
The goal is flexibility. Start simple with zkLogin, add hardware security when you want it, mix and match to fit your needs. Your Umi Signer adapts to how you want to secure your assets.

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On-chain, trustless, yours

The key insight is that none of this requires trusting Umi:
  • Policies are stored on Sui, not on our servers
  • Enforcement happens in smart contracts, not in our code
  • Rules execute even if Umi stops existing
  • You can verify everything on-chain
  • You can transfer ownership to any wallet you control
This is what decentralization actually means: you set your rules, and the system enforces them without any company having override power.

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Managing your Umi Signer

In the Umi app, you can:
  • View all active policies
  • Add or modify spending limits
  • Manage DApp authorizations
  • Set up beneficiary rules
  • Review agent permissions
  • See audit logs of all policy checks
Your Umi Signer is as flexible or as locked-down as you want it to be.