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

# Billing & credits

> How Geko meters usage, what it costs, and how credits work.

Geko bills by **input characters** — the text you send to synthesize. Billing is per **organization**, tracked as a credit balance.

## Pricing

|                    |                                                           |
| ------------------ | --------------------------------------------------------- |
| **Rate**           | **\$0.04 per 1,000 characters**                           |
| **In credits**     | 25,000 characters = **\$1.00**                            |
| **Free on signup** | **\$1.00** (25,000 characters) for every new organization |

As a rough feel: **\$1 ≈ 25,000 characters ≈ \~30 minutes** of Kazakh speech (Kazakh runs \~14 characters per second of audio).

Only **successful** synthesis is billed, on the **input** character count (the `X-Tokay-Chars` response header reports it). The catalog endpoints — `/v1/models`, `/v1/voices`, `/health` — are open and **free**.

## Running out

When your balance hits zero, synthesis requests return **HTTP 429** with a `detail` telling you you're out of credits. Top up in the [console](https://app.geko.sh). The SDK surfaces this as a `GekoError` with `status === 429` and does **not** retry it (see [Errors & retries](/sdk/errors)) — a retry can't create credits.

## Managing credits

* **Balance & history:** view your current balance and per-request usage in the [console](https://app.geko.sh).
* **Top up:** add credits in the console's billing section.
* **Estimate before you send:** `chars = text.length`, `cost_usd = chars / 25000`.

```ts theme={null}
const cost = (text: string) => text.length / 25_000; // USD
```

<Note>
  Streaming (`tts.stream`) and the OpenAI-compatible endpoint bill identically to `tts.create` — by input characters, once per request. Pricing is subject to change; the [console](https://app.geko.sh) always shows the current rate.
</Note>

## Next steps

<CardGroup cols={2}>
  <Card title="Limits & constraints" icon="gauge-high" href="/limits">
    Request limits, rate limits, and cold starts.
  </Card>

  <Card title="Errors & retries" icon="shield-check" href="/sdk/errors">
    How the SDK surfaces a 429 out-of-credits response.
  </Card>

  <Card title="FAQ & troubleshooting" icon="book-open" href="/faq">
    Common questions about usage and metering.
  </Card>
</CardGroup>