Why an agent needs a wallet
Traditional internet payments assume a person has an account, opens a checkout page, and approves a purchase. Agents make requests directly from software and may use many services during one task. They need a payment identity that works without a browser session or a separate account with every seller. A wallet provides that identity. It lets an agent:- identify itself as a payer
- sign a payment guarantee
- connect that guarantee to collateral
- pay different compatible services from one economic position
- appear in payment and audit records
- receive value when acting as a seller
A wallet is both an account and a signature
A traditional bank account mainly stores and transfers value. A wallet does that, but it also proves authorization. Every wallet has:- a public address that other systems can see
- a signer that authorizes actions for that address
Which economic actor is involved?The signature answers:
Did that actor authorize this specific action?This combination is what makes a wallet useful for autonomous software. An agent can prove authorization inside the same machine-readable flow it uses to request a service.
Wallet, agent, signer, and policy
These concepts work together, but they are not interchangeable.
An agent can use a wallet without owning unrestricted control over it. For
example, an organization can place a signing service between the agent and the
wallet. The agent proposes a payment, policy checks it, and the signing service
authorizes only allowed requests.
That separation is important. It changes the model from:
The agent has a key and can spend.to:
The agent may request payment, and a controlled system decides whether to sign.See agent identity for the broader relationship between identity, delegation, reputation, and credit.
Payer and recipient wallets
The same wallet technology appears on both sides of a payment.Payer wallet
The payer wallet:- owns the collateral behind guarantees
- identifies the buyer in signed claims
- authorizes payments
- contributes obligations to clearing cycles
- pays net debit positions
- withdraws collateral when obligations are clear
Recipient wallet
The recipient wallet is the seller’spayTo address. It:
- identifies who should receive value
- appears in payment requirements
- becomes part of the payer’s signed guarantee
- receives settlement or default coverage
- connects payment records to the seller
The wallet is the root of payment identity
4Mica connects several records to wallet addresses:- collateral ownership
- signed guarantees
- payer and recipient relationships
- clearing positions
- settlement outcomes
- withdrawals
- which agent used it
- which person or organization authorized the agent
- what the agent was allowed to buy
- why the payment happened
- whether the seller is trustworthy
How a wallet gets payment capacity
Holding tokens in a wallet is not the same as having 4Mica payment capacity. The payer deposits a supported asset into the protocol’s collateral flow. Once the deposit is finalized and recognized by Core, that collateral can back payment guarantees. The wallet’s economic state can then be understood as:
Available capacity can also depend on collateral ratios and deployment policy.
It should not be treated as an application spending budget.
The complete collateral lifecycle is covered in
deposits and withdrawals.
How a wallet authorizes payment
When an agent encounters a paid resource, the seller returns payment requirements. These describe values such as the price, asset, network, and recipient address. Before payment, the buyer application should:- verify the seller and route
- check the amount against budget
- confirm the network and asset
- decide whether approval is required
- create a unique request identifier
- ask the signer to authorize the guarantee
- payer
- recipient
- request
- amount
- asset
- time
- guarantee version
- validation policy, for V2
Wallet security is more than protecting a key
Keeping a private key secret is necessary, but it is not enough. A secure key can still authorize harmful payments if the system asks it to sign without checking:- seller identity;
- route and task context;
- price;
- network;
- asset;
- spending limits;
- duplicate or suspicious requests.
- Key security prevents unauthorized actors from using the signer.
- Policy security prevents authorized software from signing an unwanted action.
Private keys and signers
A private key is one way to control a wallet. It is not the only way. Common signer models include:
Production systems should avoid exposing raw private keys to application code
where possible. The agent should never receive a private key or seed phrase in
its prompt or tool context.
Wallets and delegated authority
An organization may run many agents without giving each one unrestricted wallet control. Delegated authority can limit:- which sellers an agent may pay;
- how much it may spend;
- which networks and assets it may use;
- how long its authority lasts;
- whether a human must approve the payment;
- which task or workload may request a signature.
One wallet or many wallets
Wallet boundaries are risk boundaries.One shared wallet
A shared wallet can use collateral efficiently because many agents draw from one position. However, one agent’s spending or failure can affect the capacity available to all others. Applications using a shared wallet need strong internal attribution and limits.One wallet per agent
Per-agent wallets provide clearer isolation, spending history, and revocation. They also require more gas management, collateral allocation, and monitoring.Wallets by role
Many systems use separate wallets for:- development and production;
- autonomous buying;
- seller revenue;
- treasury and collateral management;
- high-risk or high-value workflows.
Wallet state is network-specific
The same address can exist on several EVM networks, but balances and protocol state do not move between them automatically. A wallet may have:- collateral on Base but not Base Sepolia;
- USDC on one network but a different token contract on another;
- enough collateral but not enough native gas;
- different guarantees and settlement obligations on each network.
Buyer wallet policy
Collateral answers how much the protocol can trust the wallet to guarantee. Application policy answers how much the agent should be allowed to spend. Those limits are not the same. A wallet might have$1,000 of available capacity while one agent is allowed
to spend only:
$0.10per request;$5per task;$20per day;- only on approved data services;
- only on Base using USDC.
Recipient wallet identity
For sellers, a stable public wallet address helps buyers detect impersonation. The samepayTo address should appear consistently in:
- payment requirements;
- API documentation;
- marketplace and registry profiles;
- support material;
- internal settlement records.
Wallet lifecycle
A wallet moves through a lifecycle:- Created: the address and signer are provisioned.
- Funded: the wallet receives gas and supported assets.
- Registered: collateral is deposited and recognized by Core.
- Active: the wallet signs or receives payments.
- Paused: new signing is stopped while existing obligations continue.
- Rotated: signer authority or the public address changes.
- Retired: obligations resolve, collateral exits, and active authority is removed.
Rotation and revocation
Signer rotation and wallet-address rotation solve different problems. Signer rotation changes the authority that controls future actions while keeping the public wallet identity. Address rotation creates a new economic identity. It affects collateral, allowlists, seller verification, payment requirements, and historical reconciliation. Prefer signer rotation when the wallet address can remain secure. If the public address changes, preserve old records and publish the new address through a trusted channel.If a wallet may be compromised
A wallet incident has two timelines:- future actions that can still be stopped;
- existing obligations that may remain valid.
- pause the agent and signing path;
- preserve logs and note the suspected exposure time;
- identify guarantees and transactions after that time;
- revoke or rotate signing authority;
- inspect collateral, allowances, clearing positions, and withdrawals;
- reconcile application, Core, and chain state;
- resume only after policy and authority are restored.
What users should be able to see
A useful wallet view should answer:- Which address and network am I using?
- Is this a payer, recipient, or both?
- Which signer or agent is authorized?
- What assets and gas are available?
- How much collateral is total, locked, and available?
- Which guarantees and settlement obligations remain open?
- Which payments were signed, and why?
- Is a withdrawal pending?
- Can signing be paused or revoked?