# Choose a tier

> When to run on Flash, Max or Heavy, and how each run is billed.

Every run thinks with **SuperCosmos by Clatter Labs**. Set `tier` when you create a run:

| `tier` | Behaviour | Use it for |
| --- | --- | --- |
| `auto` (default) | Cosmos routes each step | Most runs |
| `flash` | Fastest; answers without extended thinking | Small edits, scripts, lookups, high volume |
| `max` | Thinks before acting | Building features, debugging, multi-file changes |
| `heavy` | Thinks longest, longest answers | Hard bugs, large builds, deep reasoning |

## How runs are billed

Tokens are billed at the tier each call **actually ran on**. A run with `tier: "auto"` is billed at Flash rates. Computer time, tool actions, browser time and storage are billed the same way on every tier.

| Tier | Input / 1M tokens | Output / 1M tokens |
| --- | --- | --- |
| Flash | $1.60 | $3.40 |
| Max | $1.80 | $3.80 |
| Heavy | $2.00 | $4.40 |

**Long-context input above 262K tokens: 1.5×** (SuperCosmos): a request whose prompt is over 262K tokens bills its whole input at 1.5× the rate above.

<Tip>
Start with `auto` or `flash`. Move a run type to `max` or `heavy` only when you see it struggle: more steps, failed checks, or answers that miss the point.
</Tip>

See [SuperCosmos models](/models/overview) for more on each tier and [Rates](/billing/rates) for every price.