> ## Documentation Index
> Fetch the complete documentation index at: https://docs.costgraph.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Billing exports

> Report each customer's attributed cloud spend to the platform that invoices them

CostGraph reports each customer's attributed cloud spend to your billing
platform every night. You decide which customer each charge belongs to with a
virtual tag. The platform prices and invoices what CostGraph reports.

This is your customers' billing. It has nothing to do with how you pay
CostGraph.

## How the export works

1. A **virtual tag** assigns each charge to a customer. Every value the tag
   produces is an id in your billing platform.
2. A **meter** binds that tag key to one meter in the platform. Each night
   CostGraph reports every customer's spend for each settled day to that meter.
3. The **platform prices and invoices** what was reported.

CostGraph reports spend in integer cents. Price the meter per cent, or divide
by 100 on the platform. No platform checks the unit, so a price set as if the
values were dollars bills 100 times too much.

## Platform differences

The platforms disagree on what they bill and how they treat corrections. The
following table shows what each one expects; the platform pages cover the
details.

| Platform                                               | Tag value                | Meter              | Unknown id             | Corrections               |
| ------------------------------------------------------ | ------------------------ | ------------------ | ---------------------- | ------------------------- |
| [Autumn](/costgraph/integrations/exports/autumn)       | Customer id              | Meter              | Creates the customer   | Sent as the difference    |
| [Chargebee](/costgraph/integrations/exports/chargebee) | Subscription id          | Metered item price | Rejected               | Replaces the day's record |
| [Lago](/costgraph/integrations/exports/lago)           | External subscription id | Billable metric    | Rejected               | Sent as the difference    |
| [Metronome](/costgraph/integrations/exports/metronome) | Customer id              | Event type         | Accepted, bills nobody | Sent as the difference    |
| [OpenMeter](/costgraph/integrations/exports/openmeter) | Subject                  | Meter              | Creates the subject    | Sent as the difference    |
| [Orb](/costgraph/integrations/exports/orb)             | External customer id     | Event name         | Rejected               | Sent as the difference    |
| [Stripe](/costgraph/integrations/exports/stripe)       | Customer id              | Meter              | Rejected               | Sent as the difference    |

Where a platform creates an unknown id, a mistyped tag value becomes a new
billable customer. Where it accepts one silently, the spend is reported but
not invoiced. Check the tag's values against the platform before you bind a
meter, and review the first night's report after any rule change.

## Tag spend by customer

Create a virtual tag key with the platform's prefix, such as
`stripe_customer`. Only prefixed keys can be bound to a meter. The value a rule
assigns is the id the spend is reported under, so set the **Tag value** to the
customer's id in the platform.

The following rule bills everything in one linked account to one customer:

| Field      | Operator | Match value    | Tag value   |
| ---------- | -------- | -------------- | ----------- |
| Account id | is       | `416508157375` | `acme-corp` |

Any field works as the match: a linked account, a resource name prefix, a
project, or an existing tag. CostGraph doesn't report spend the tag doesn't
match. See [Virtual tags](/costgraph/virtual-tags/usage) for the rule builder
and how overlapping rules resolve.

Group the cost overview by the tag key to see what each customer is billed
before it's reported.

### Protected days

A bound tag key drives invoices, so CostGraph protects days it has already
reported. Rules on the key can't be reordered. A new or edited rule must start
on a date that hasn't been reported yet. To retire a rule, give it an end date
instead of editing it in place.

## Nightly runs

Cloud providers restate recent spend. CostGraph holds each day for two days
before reporting it, then keeps reconciling the last 35 days. A day that
changes after it was reported is sent again as a correction.

Each run reports only what changed, so an unchanged day sends nothing.

Every report carries the same reconciliation fields. They let you explain any
charge from the platform's side:

| Property                       | Meaning                                            |
| ------------------------------ | -------------------------------------------------- |
| `usage_date`                   | The day the spend belongs to                       |
| `correction`                   | Whether this report adjusts a day reported earlier |
| `previous_total` / `new_total` | What the day's total was, and is now               |
| `currency`                     | The currency the meter is denominated in           |

CostGraph holds a day back rather than report it wrong when its spend mixes
currencies or a quantity meter meets an unexpected unit. Each held day is
recorded with its reason.

Deactivating a meter stops reporting but keeps its history. Reactivating it
resumes from what was already sent, so the window isn't billed twice.