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

# Budgets

> Set spend limits per account, track utilisation in real time, and receive alerts at configurable thresholds.

## Overview

Budgets let you define a spend ceiling for a cloud account (or across all accounts) and receive alerts when spend crosses warning or critical thresholds. Cost Optix tracks actual spend throughout the month and projects end-of-period spend using historical patterns.

## Creating a Budget

Go to **Budgets → New Budget**:

| Field              | Description                                                       |
| ------------------ | ----------------------------------------------------------------- |
| Name               | A descriptive label                                               |
| Amount             | The spend limit in USD                                            |
| Period             | `monthly`                                                         |
| Account            | A specific connected account, or `multi-account` for all accounts |
| Warning threshold  | Percentage triggering a warning alert (default 80%)               |
| Critical threshold | Percentage triggering a critical alert (default 95%)              |

## Alert Thresholds

| State    | Default trigger | Webhook event     |
| -------- | --------------- | ----------------- |
| Warning  | 80% of budget   | `budget.warning`  |
| Critical | 95% of budget   | `budget.critical` |
| Exceeded | 100% of budget  | `budget.exceeded` |

Thresholds are configurable per budget. See [Webhooks](/features/webhooks) to receive alerts in Slack, Teams, or Discord.

## Budget Risk (Value at Risk)

Alongside current spend, each budget card shows a **Predicted** value — a statistically derived estimate of worst-case end-of-period spend. This is calculated from up to 11 months of historical data for that account. When historical data is limited, it falls back to linear extrapolation.

## Tag-Scoped Budgets

<Info>
  Tag-scoped budgets are available on **Professional and above**.
</Info>

A tag-scoped budget tracks spend only for resources matching a specific tag key/value combination, rather than an entire account. Useful for tracking spend by team, environment, or project.

### Adding tag filters

When creating a budget, add one or more tag filter rules:

| Field    | Description                                     |
| -------- | ----------------------------------------------- |
| Key      | The tag key (e.g. `team`, `env`, `project`)     |
| Operator | `=` for exact match, `in` for multiple values   |
| Value    | The tag value, or comma-separated list for `in` |

**Examples:**

```
team = payments
env in [production, staging]
project = checkout-v2
```

Multiple filters on a single budget are AND-ed — spend must match all filters to be counted.

### How tag-scoped spend is calculated

Cost Optix resolves tag-scoped spend from the same data source as the Tag Explorer:

* **Azure** — Consumption Tags API + Usage Details API
* **AWS** — tag cost aggregates (synced from Cost Explorer)
* **GCP** — BigQuery UNNEST query over the billing export dataset

For `multi-account` budgets with tag filters, Cost Optix sums the matching tag-scoped spend across every active account.

## Editing and Deleting

Open a budget and click **Edit** to update any field. Changes take effect immediately. Deleting a budget is permanent.