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

# Billing & Credits

> Per-token billing, credit management, and spending caps.

Theo uses per-token billing with a credit system. 1 credit = 1 cent.

## How Credits Work

Every API call consumes credits based on the tokens processed. The cost depends on which Theo engine handles the request:

| Engine                     | Cost        | Best For                    |
| -------------------------- | ----------- | --------------------------- |
| Theo Flash (`fast`)        | Lowest      | Simple Q\&A, classification |
| Theo Reason (`think`)      | Medium      | Deep reasoning, analysis    |
| Theo Code (`code`)         | Medium-High | Code generation             |
| Theo Create (`image`)      | Per-image   | Image generation            |
| Theo Research (`research`) | Variable    | Web research                |

* **Cache hits cost 0 credits** — identical cached requests are free
* **Usage is tracked in real-time** in the dashboard
* Credits are deducted immediately after each completion

## Add Credits

1. Navigate to **Billing** in the dashboard sidebar
2. Click **Add Credits**
3. Choose an amount or set up auto-top-up
4. Complete payment via the secure billing portal

## Auto-Recharge

Keep your balance topped up automatically. Pick an amount and a cadence (weekly or monthly), and we'll add credits on that schedule using the card on file. Cancel anytime from the billing portal.

## Spending Caps

Protect against unexpected charges by setting spending limits:

* **Daily cap** — maximum credit spend per day
* **Monthly cap** — maximum credit spend per billing cycle
* **Per-key caps** — limit individual API keys independently

When a cap is reached, requests return `402 insufficient_credits` until the cap resets or is raised.

## Monitoring

* Real-time credit balance in the dashboard header
* Per-request cost visible in every API response (`usage.cost_cents`)
* Historical cost breakdown in [Usage & Analytics](/dashboard/usage-analytics)
* Alerts when balance drops below a configurable threshold

## Test vs. Production Keys

| Key Prefix      | Billing          | Rate Limits  |
| --------------- | ---------------- | ------------ |
| `theo_sk_test_` | No billing       | Lower limits |
| `theo_sk_live_` | Billed per token | Full limits  |