# Billing and quota

> Input, output and cache-read are priced separately; prepaid balance stops at zero and failed requests are not billed.

## How pricing works

Pricing is **per token component**, in USD per 1M tokens:

- **Input**: prompt tokens in the request
- **Output**: tokens the model generates
- **Cache read**: the portion that hits upstream prompt cache, usually much cheaper than input
- **Per call**: a few image models bill per call instead of per token

Embedding and rerank models have no output tokens; their output column shows `—`, which is not zero.

Current per-model prices are on [Models](/en/models/); the full price list and discounts are on
[www.tokrouter.dev/pricing](https://www.tokrouter.dev/pricing/).

## Quota

- Account balance is denominated in USD and prepaid
- A token can set a `monthly_quota` cap: this is a **soft cap** — once reached, that token's requests
  are rejected, but other tokens on the account keep working
- A zero balance is a **hard stop**: every request returns an insufficient-quota error until you top up

<Callout type="info" title="Failed requests are free">
Upstream errors, timeouts and requests rejected by the gateway are not charged. Only requests that
actually returned tokens count toward usage.
</Callout>

## Rate limits

Rate limits are configured per account group on **RPM** (requests per minute) and **TPM** (tokens per
minute). Exceeding them returns `429` with a suggested retry delay in the headers.

<Callout type="warn" title="Handling 429">
Do not retry immediately — wait per `Retry-After` or use exponential backoff. A retry storm at full
concurrency keeps the limit pinned longer.
</Callout>

## Controlling cost

1. **Tier by task**: plan with a strong model, execute in bulk with a fast one — often an order of
   magnitude cheaper
2. **Use cache**: repeated prefixes (system prompts, long documents) hit the far cheaper cache-read price
3. **Cap output**: `max_tokens` is the only reliable output bound
4. **Cap per token**: give experimental projects their own token with a `monthly_quota`
5. **Look before tuning**: the console's usage page splits by model and token — find the biggest slice first