Cash Guardrail
by
Daily spend limits for ecommerce teams: set today's cap against the cash actually available after committed outflows, so paid never runs ahead of the bank balance.
Ad budgets are set monthly and spent daily, against a bank balance that moves every hour. Between them sit the things nobody watches together: a purchase order clearing on Thursday, payroll next week, receivables that are eight days late, a payment processor holding a reserve. The result is a spend cap that was right when it was set and wrong by the middle of the month. This skill reads cash position, committed outflows and expected receipts, computes what is genuinely available today, and sets a daily spend cap that leaves the business its buffer.
What It Does
- Reads current cash position across accounts, including processor balances.
- Subtracts committed outflows: purchase orders, payroll, tax, recurring costs.
- Adds expected receipts weighted by how reliably they have arrived before.
- Computes the cash genuinely available after the buffer you set.
- Converts that into a daily spend cap for the days remaining.
- Flags the day the current run rate would breach the buffer.
Use Cases
- Keep paid spend from outrunning the bank balance in the second half of a month.
- See the day a purchase order and payroll land in the same week.
- Give a media buyer a number that already accounts for the cash side.
- Raise the cap deliberately when receivables land, rather than by feel.
Example Session
What can we safely spend on ads per day for the rest of the month?
Your cap should be $3,900 a day, not the $5,200 the monthly budget implies. Here is why.
- Line | Amount | Timing
- Cash across accounts | $412,000 | Today
- Processor reserve, unavailable | Minus $38,000 | Released in 14 days
- Purchase orders committed | Minus $186,000 | Oct 9 and Oct 22
- Payroll and tax | Minus $94,000 | Oct 28
- Receivables, weighted | Plus $61,000 | 8 to 21 days
- Buffer, 30 days of fixed cost | Minus $78,000 | Held
- Available for discretionary spend | $77,000 | 20 days remaining
The squeeze is Oct 22 to Oct 28, when the second purchase order and payroll land six days apart. At $5,200 a day you breach the buffer on Oct 24. At $3,900 you do not, and if the late receivable lands before Oct 20 the cap goes back up to $5,000 for the remainder.
Why This Beats Prompting It Yourself
A Monthly Budget vs Today's Cash: The Hidden Risk
A generic prompt divides the monthly budget by the days remaining. That number ignores every commitment between now and month end, and it is the same number on the day before payroll as on the day after a large receipt lands. The cap is right on average and wrong exactly when being wrong is expensive.
When You Still Need The Committed Outflows
A spend cap is only safe if it knows what is already spoken for. This skill states $412k in the bank becoming $77k of genuinely discretionary cash, with the purchase orders, the payroll and the processor reserve that did it. It also names the day a breach would happen at the current rate, which is what turns a limit into a decision someone can plan around.
Known Limitations
Receipt weighting comes from your own payment history, so a business with few customers or lumpy invoicing gets a wider range and the output shows it. Purchase order timing depends on your suppliers invoicing when they said they would, which is the assumption most likely to break. It sets the cap and flags the breach date but does not change budgets in any ad account.
Install It
- Download the ZIP.
It is free and there is no account to create. - Unzip it into your agent's skills folder.
Claude Code reads ~/.claude/skills/, which is hidden by default: the command in the folder block opens it. Other agents scan their own directory, so drop the same folder there instead. - Ask your agent to use it.
Restart the agent if it was already running, then it picks the skill up with no config.
skills folder
Copy
~/.claude/skills/cash-guardrail/
SKILL.md
references/buffer-rules.md
caps/
# one cap per day, with the cash build
# macOS: create the folder and open it in Finder
mkdir -p ~/.claude/skills && open ~/.claude/skills
# Windows: paste in the Explorer address bar
%USERPROFILE%\.claude\skills\Frequently asked questions
How is this different from checking the bank balance?
The balance tells you what is there, not what is spoken for. This subtracts committed outflows, holds back the buffer you set, weights expected receipts by how reliably they arrive, and converts what is left into a daily number. The gap between the two figures is usually large.
Which agents does the skill run in?
Any agent that supports the open SKILL.md format: Claude Code, Cursor, Codex CLI, GitHub Copilot, Gemini CLI, Manus, Grok and others load it unmodified. The format is portable, the location is not. Each agent scans its own skills directory, so you drop the same folder into whichever one yours uses. There is no config file to edit and no API key to provision.
What does it need connected to work?
Bank and processor balances, committed purchase orders with dates, payroll and recurring costs, and receivables. Missing any of them narrows what it can see, and the output names the inputs it did not have rather than assuming they are zero.
How is the buffer decided?
You set it, usually as a number of days of fixed cost. The skill holds it back before computing anything discretionary. Where your buffer is thinner than the volatility in your own receipts, it says so rather than treating your number as safe.
Does it stop my ads when the cap is reached?
No. It publishes the cap and flags the breach date, and a person applies it in the ad accounts. Automatic spend cuts driven by a cash model are how a business stops selling in the week it most needs to.
What is included with the skill?
The skill itself, the buffer rule reference, the daily cap template, and the receipt weighting method. It is free and security scanned. We re-publish the ZIP when the weighting model changes, so download it again if your caps start moving unexpectedly.
A spend cap is only safe if it knows the cash behind it.
Polar joins cash position, receivables and committed spend in one semantic layer, so today's limit reflects the real balance.
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