# Brex budget and spend limit control room for finance

> See every budget and spend limit ranked by how close it is to its cap, then raise, lower, create or retire caps without leaving the page.

- Workflow type: app
- Services: Brex, Slack
- Categories: Finance, Operations
- Published: 2026-08-14

## What it does

- Puts every Brex budget and spend limit on one board, each showing the amount spent against its cap with a percent consumed bar.
- Sorts the board so whatever is closest to going over sits at the top, so you see trouble before it lands.
- Opens any budget or limit to show who is on it and the card charges feeding it, with real names and departments instead of ids.
- Lets finance raise, lower, create or retire a cap on the spot, and post the current at risk list to a finance channel in Slack.

## What you'll need

- A Brex account with permission to view and manage budgets and spend limits.
- A Slack workspace, and the channel where finance wants the at risk list posted.
- Budgets or spend limits already set up in Brex, so the board has something to show on day one.

## Prompt

Build me an internal control room app where our finance team reviews and adjusts Brex budgets and spend limits in one place, instead of clicking through separate Brex settings screens. The people using it are finance reviewers who already know what a budget is, so favor density and fast scanning over hand holding.

The landing view is a board of every budget and every spend limit on the account. Load budgets with Brex List budgets, spend limits with Brex List spend limits, and budget programs with Brex List budget programs so each card can show which program it belongs to. Every card shows the name, the program or owner it sits under, the amount spent, the cap, and a percent consumed bar. Sort the board so whatever is closest to breaching sits at the top, ranking by percent consumed descending, and let the reviewer filter to budgets only, spend limits only, or a single budget program.

Brex returns money as integer minor units together with a currency code, so an amount of 1000 with currency USD means ten dollars. Format for display using the currency code that comes back with each value rather than assuming dollars or dividing by one hundred everywhere, and keep the raw minor unit integers for the arithmetic behind the percent bar so nothing drifts through rounding. On any write back to Brex, convert the reviewer's input back into integer minor units with the correct currency code, never a formatted display string.

The warning and danger thresholds on the percent bar must be configurable rather than hardcoded. Default them to 80 percent for warning and 95 percent for danger, expose them in a settings area of the app, and persist the chosen values so they survive a reload and apply everywhere, including the at risk list. Color each bar and card by which threshold it has crossed.

Clicking a card opens a detail panel for that budget or spend limit. Use Brex Get spend limit to pull the full record when the card is a spend limit. Show its members, and show the card transactions feeding it from Brex List primary card transactions, scoped to that budget or spend limit and its current period. Join both the members and the transactions to real people with Brex List users, and label each person with their department using Brex List departments, so the reviewer sees who is spending rather than a bare user id.

From the detail panel the reviewer can raise or lower a cap. Use Brex Update spend limit for a spend limit and Brex Update budget for a budget, prefilling the current cap and validating that the new amount is a positive integer in minor units before saving. The reviewer can also create a new one from the board with Brex Create budget or Brex Create spend limit, choosing the program, owner and period in the form. After any write, refresh the affected card so its percent bar and position in the sort reflect the new cap immediately.

Retiring a stale one goes behind an explicit confirmation step. Use Brex Archive spend limit for a spend limit and Brex Archive budget for a budget. Archiving a budget in Brex also disables that budget's child spend limits, so the confirmation copy for a budget has to say that out loud, name how many child spend limits will be disabled, and require the reviewer to confirm before anything is sent. Do not let an archive fire from a single click anywhere in the app.

Add an action that posts the current at risk list to a finance channel using Slack Send a Message. The at risk list is every budget and spend limit at or above the configured warning threshold, ordered by percent consumed descending, formatted as a readable message with the name, the spent against cap amounts, and the percent consumed for each entry. Let the reviewer pick the channel and remember the last channel used.

## How to customize

- Change the warning and danger levels on the percent bar, which start at 80 percent and 95 percent.
- Pick which Slack channel the at risk list gets posted to.
- Filter the board down to budgets only, spend limits only, or a single budget program.

## FAQ

### Does this actually change things in Brex, or is it just a report?

It changes them. Raising or lowering a cap, creating a new budget or limit, and retiring an old one all write straight back to Brex, and the board updates to match. Anyone who only wants a read-only recap is better served by a weekly summary instead.

### What happens when I archive a budget?

Archiving a budget in Brex also disables the spend limits underneath it. The app spells that out in the confirmation step, including how many child limits will be switched off, so nobody retires a budget without realising what goes with it.

### Can someone accidentally delete a budget with one click?

No. Every archive action sits behind an explicit confirmation step that names what is being retired and what else it affects. Nothing is archived from a single click anywhere in the app.

### Will it show the right currency?

Yes. Amounts are displayed using the currency that comes back with each budget or limit, so accounts running more than one currency read correctly rather than everything being shown as dollars.

### Who is allowed to make changes?

Whatever the connected Brex account is allowed to do. If that login cannot manage budgets in Brex itself, it cannot manage them here either, so access stays governed by your existing Brex permissions.

Use this prompt in General Input: https://www.generalinput.com/prompts/brex-budget-and-spend-limit-control-room-for-finance