## Overview

Every time the platform uses an AI model — the Robot replying to a customer, a dashboard being
generated, the onboarding briefing, the quality judge, the copilot, a voice call — that costs money,
measured at the moment of the call. The Brain's **Usage** tab gathers those costs and answers the
question that comes up every time the invoice arrives: **what did THIS account spend, and on what**.

The figure is not an estimate. It is the sum of the measurements taken on each call: how many calls,
how many tokens went in, how many came out, how many were served from the provider's cache (billed at
a discount), and what it cost.

## Prerequisites

- The **Brain** module must be enabled on the account.
- You must be an **administrator**. This is the only Brain read restricted to administrators, for a
  simple reason: invoice information is not support information. An agent reading the inbox does not
  need to read the bill.
- The AI service must be reachable. If it is not, the screen shows an **error** — never a zero.

## Step by step

1. Open **Brain** in the sidebar.
2. Go to the **Usage** tab.
3. Pick the period in the top right: **7**, **30** or **90 days**. The window IS the question:
   changing the period reloads the numbers.
4. Read top to bottom:
   - the four cards summarise the whole period — cost, calls, tokens and cached tokens — and each one
     carries underneath the average that is usually the next question: cost per day, calls per day,
     tokens per call and **how much of the prompt came from cache** (that is the provider's discount:
     when the percentage drops, the bill rises without the volume moving);
   - the chart shows spend day by day, with the scale on the left, dates along the bottom, the **peak
     day highlighted** and, in the footer, how many days of the period actually had spend — a nearly
     flat line reading "3 of 90 days with spend" is information, not an empty chart;
   - the lists below break the same total down by **surface**, by **model** and by **Robot**, each row
     with its **share of the total**, its call count and its **cost per call**;
   - the **Per conversation** section lists the most expensive conversations of the period, each with a
     **link that opens the conversation**, its cost, how many turns it had and its **cost per turn**.
5. Use the **filter bar** at the top to cross the questions: surface, model, Robot and conversation.
   The filters combine, and they redo the read — they do not hide rows on screen, they change the
   query. Filtering by one Robot and watching the total drop is the confirmation that this Robot
   accounts for that share.

Amounts below one cent are shown with the decimals they need (for example `US$ 0.004933`). A model
call costs fractions of a cent: rounding to two decimals would print `US$ 0.00`, which reads as
"nothing was measured".

### Per conversation

Until now this screen answered "what did the account spend". **Per conversation** answers "what did
THIS conversation cost" — the question that comes up when one conversation drags on, or when someone
wants to know whether a particular case turned out expensive.

A conversation's cost includes what it spent outside the reply turn: transcribing the audio the
customer sent, the audio the Robot replied with, the voice call. Those used to land in a row that
could not be linked back to the conversation that caused them.

**Sub-agents and delegation.** When a Robot delegates to a sub-agent, the sub-agent's tokens are
already counted on the caller's turn. The screen shows the delegation so you know it happened, but its
cost is **not added again** — adding it would count the same tokens twice and inflate exactly the
number this screen exists to make trustworthy.

### Unpriced surfaces

Not everything that consumes AI has a price table. Audio transcription is billed per second, speech
synthesis per character, image and video per unit — and the platform **does not have** the price table
for those. So they show up **counted and labelled**, measured in their own unit ("3,412 characters
synthesized"), and **never as `US$ 0.00`**.

The distinction is the whole point: `US$ 0.00` reads as "this was free". A surface labelled unpriced
reads as "this consumed something, and the platform does not know what it cost" — which is the truth.
The priced total remains a trustworthy total; it simply is not the whole invoice, and the screen says
so instead of letting you add it up wrong.

## Settings & options

There is nothing to configure here: the tab is read-only. What moves the numbers is usage — how many
conversations the Robot handles, how many dashboards get generated, whether the quality judge is
sampling turns, and which model each Robot uses.

To change a Robot's model (and therefore its cost per call), use the **Robots** screen. To change who
grades quality, use the Brain's surface assignment.

## Use cases

- **Closing the month.** You get the provider's invoice and want to know how much of it is this
  account.
- **Finding where the money goes.** Almost always the answer is "customer replies" — it is the surface
  that runs most often. When it is not, that is worth a look: a dashboard generated over and over, or
  a judge pointed at an expensive model, shows up immediately in the by-surface list.
- **Comparing Robots.** The per-Robot breakdown shows which one consumes most, which usually reflects
  conversation volume rather than waste — but sometimes reflects an expensive model chosen without
  need.
- **Seeing the cache work.** Cached tokens are billed at a discount. A high number there means the
  system prompt is stable and being reused; a sharp drop usually means something in the prompt changed.
- **Investigating an expensive conversation.** The **Per conversation** section sorts by cost. Opening
  the most expensive one and checking its turn count separates two different causes: a long
  conversation (many cheap turns) and a heavy one (few expensive turns, usually a large model or a lot
  of context).
- **Finding the cost of voice.** Filter by the audio surfaces to see how much transcription and
  synthesis the account consumed — in seconds and characters, since no dollar price exists for them.

## Tips, limits & best practices

- **Values are in US dollars.** That is the currency the provider bills in and the measurement was
  taken in. Converting here would invent an exchange rate the platform never observed.
- **The by-model breakdown is partial, and the screen says so.** Customer replies are measured without
  recording which model replied, so their cost lands in the total, in the by-surface list and in the
  daily chart, but not in the by-model list. When that happens, a line states how much of the total
  the list covers. Adding up only the by-model list and taking it for the whole bill is exactly the
  mistake that line exists to prevent.
- **No spend in the period is not an error.** If the account genuinely did not use AI, the screen
  explains that. If the service is down, it shows an error with a retry button. The two situations are
  different and the screen never swaps one for the other.
- **The maximum window is 365 days.** Longer periods are clamped, not refused.
- **A day with no spend shows as a day with no spend** — not as a gap in the line.

## Troubleshooting

**The tab does not appear.** The Brain module is disabled on the account, or you are not an
administrator.

**An error shows instead of the numbers.** The AI service did not answer. Nothing is rendered as zero
on purpose: a made-up figure here would be worse than none. Use **Try again**; if it persists, it is
one for whoever runs the installation.

**The total does not match the provider's invoice.** Two common causes: the invoice covers the whole
installation (every account) while this screen covers one account; and the price table used at
measurement time may be out of date with the provider. Talk to whoever runs the installation.

**The by-model list adds up to less than the total.** Expected, and the screen warns about it — see
"Tips, limits & best practices" above.

**A surface shows calls but no dollar amount.** That is deliberate: transcription, speech synthesis,
image and video have no price table in the platform. Their measurement is in their own unit (seconds,
characters, units). That is not the same as zero cost, and the label exists precisely so you do not
confuse the two.

**The by-surface and by-conversation totals do not match exactly.** A conversation only appears under
"Per conversation" if its spend could be linked to it. Account work that belongs to no conversation —
a generated dashboard, the onboarding briefing, the daily improvement cycle — counts toward the total
and the surfaces, and correctly counts toward no conversation.

## See also

- [Analytics and generative dashboards](/hc/ajuda/articles/maestro-brain-analises-e-dashboards-generativos-en)
- [Advanced model settings](/hc/ajuda/articles/maestro-brain-ajustes-avancados-do-modelo-en)