Receipts
One per payment, in or out, signed and hash-chained into an audit trail.
How it works
Your Safe, your rules, one key for the agent.
Purser turns a Safe you own into an account an AI agent can use on its own, without ever being able to empty it.
The account
Each agent gets its own Safe. You own it.
The agent never becomes an owner of the Safe. It holds a session key that can only act through the Purser policy module, and the module checks every rule before a single unit moves.
- Non-custodial. There is no Purser balance and no pooled account.
- One transaction to open. The Safe is created and the module enabled together.
- An on-chain identity. The agent is registered in the ERC-8004 identity registry.
- You can leave. The module can be switched off in one Safe transaction.
YouOwner, with MetaMask
owns
Agent accountA Safe that holds the funds
enforced by
Purser policy moduleRules, approvals, freeze, fee
acts only through
Agent keyScoped, revocable, never an owner
The rules
Set once, enforced on every payment.
Rules live in the module on chain. Changing them is a transaction only the owner can sign.
Budgets
A daily and a weekly budget per token. The fee counts toward the budget.
Largest single payment
No single payment may be larger than the amount you set.
Per counterparty limit
A cap on what any one payee can receive per day.
Allowlists
The contracts, x402 payees, models and services the agent may pay.
Time windows
The hours and weekdays, in UTC, when the agent may spend.
Rate limit
The most payments the agent may make per minute.
Approval above an amount
Larger payments wait in a queue until you approve with a passkey or MetaMask.
Co-sign
Above a threshold, a second agent key has to sign as well.
Freeze and recovery
Freeze at once. Add a recovery key that takes effect after a waiting period you can cancel.
One payment
What happens between the request and the receipt.
Every payment takes the same path, whether it is a model call, an x402 service or a contract call.
Request
The agent asks to pay a model, a service or a contract with its key.
Rules
Budgets, limits, allowlists and time windows are checked.
Firewall
The payment is simulated and screened for drains and hidden instructions.
Approval
If it is above your limit, it waits for you or a co-signer.
Settle
The module moves the funds from your Safe to the payee.
Receipt
A signed receipt is written and shown in your dashboard.
A payment that fails a rule or the firewall stops there. It never reaches the chain, and you see the reasons.
Safety
Three layers, each with a different job.
The rules say what is allowed. The firewall looks at each payment. The watchdog looks at the pattern.
Rules
Hard limits in the contract. A payment that breaks one is rejected by the module itself, whatever the agent was told.
Firewall
Simulates every payment before it is signed and checks for balance drains, unknown contracts, approvals to unknown spenders and prompt-injection markers.
Watchdog
Keeps a baseline per agent. Spikes, loops and strange new counterparties freeze the account if you enabled it, with the reason sent to you.
The books
Know what each agent costs and what it brings in.
Receipts add up to real accounting, per agent and per team.
Profit and loss
Cost per task and per model, revenue per customer, CSV export.
Teams
A shared treasury Safe with budgets per agent and department.
Treasury
Idle balance can move into an on-chain vault from your own Safe.
The lines Purser does not cross
What Purser never does.
Purser is software that enforces rules on an account you own. It is not a bank.
- Never: hold your money. Funds sit in your own Safe at all times.
- Never: issue cards or lend money.
- Never: ask for an application or identity documents.
- Never: let an agent's key move funds outside the rules.