Can an AI agent invest surplus cash?

Not by itself. Placing a deposit or buying a money market instrument moves money, so it sits at depth 4. What an AI agent can do is work out how much cash is truly surplus, test candidate placements against the investment policy and draft the instruction. The treasurer approves, and a different person releases the funds.

Why is "surplus" harder to measure than it looks?

The bank balance is not the surplus. Cash that looks idle may be needed for next week's payroll, a tax payment, or a supplier run that has been approved but not released. Some of it may not even be yours yet: customer receipts that sit unallocated, which is where the work on clearing unapplied cash matters, can include overpayments that must go back.

So the agent's first contribution is a better number. It combines the cleared bank balances with committed outflows, the cash flow forecast and the liquidity buffer the policy requires. The surplus is what is left after all of those, for each period the investment would run.

What conditions does the agent need?

1. An approved investment policy. Permitted instruments, approved counterparties, limits per counterparty, maximum maturity and the minimum liquidity buffer, stated as numbers.
2. Sealed cash data. Balances from the bank feeds, committed payments from the payment system, not a spreadsheet someone maintains.
3. A forecast with sources labelled. Contracted receipts, which are reliable, are kept apart from expected sales, which are declared estimates.
4. No release rights. The agent cannot instruct a bank, open a deposit or move funds.

What does the agent prepare, and what stays with people?

The agent prepares, at depth 1 or 2: - the surplus calculation by horizon, showing every deduction; - a maturity ladder that keeps cash available for known outflows; - candidate placements that fit the policy, with indicative rates from approved counterparties; - a check of counterparty limits after each proposed placement; - the draft instruction for the approved placement.

People: - the treasurer approves the amount, term and counterparty; - a second authorised signatory releases the funds at the bank; - the finance director approves any exception to the policy.

The release is the step that keeps the separation of duties. The person who decides on the investment is not the one who moves the money, and the agent is neither.

An illustrative example

Take a mid-sized retailer after its seasonal peak. The bank balance is 9 million.

The agent deducts approved but unreleased supplier payments of 2.5 million, payroll and tax due within the month of 1.8 million, and the policy buffer of 1.5 million. It also finds 400,000 in unallocated receipts, of which a share are likely overpayments, so it excludes them until they are cleared. That leaves a surplus of about 2.8 million for one month and less for three, because a large stock payment falls due in month two.

It proposes a one-month deposit of 2.8 million split across two approved banks to stay inside the counterparty limit. The treasurer approves one-month terms but reduces the amount to 2.5 million, keeping extra headroom for returns. The agent drafts the instructions, and the treasury manager releases them at the banks.

What controls make it safe?

• The policy is the boundary. Proposals outside it are refused and explained, not offered as options.
• Counterparty limits checked on every proposal. Including existing deposits with the same bank.
• Two people for each placement. One approves, one releases, both named.
• Maturities matched to outflows. The ladder shows when each deposit returns against when cash is needed.
• A record per decision. Calculation, proposal, approval and release are filed together.

Where Pryme fits

In Pryme, sizing surplus cash and moving it are separate capabilities, and the agent's role scope does not include the second. Committed payments and bank balances arrive as sealed sources; forecast sales arrive as declared, and the surplus calculation shows which is which. Every proposal and its verdict are filed.

The wider controls are in AI agents for finance: books you can audit. The cash flowing in starts with order-to-cash, so cleaner receipts make the surplus figure more reliable.