# Choose a model

> Find a model id, check its price and context, and send it to the right endpoint.

A model id has the form `author/name`, for example `anthropic/claude-sonnet-5.5`. Send it as `model` on every endpoint.

## Browse the catalog

[Models](https://deference.si/models) lists every model with its context length, price per million tokens and capabilities. Open a model to copy its id and a ready-to-run example.

Pick a maker in the maker bar, choose a capability in the **Capabilities** menu, or link straight to a filter:

| Capability | Link                      | Shows                                |
| ---------- | ------------------------- | ------------------------------------ |
| All        | `/models`                 | Every listed model                   |
| Reasoning  | `/models?type=reasoning`  | Models that think before they answer |
| Tools      | `/models?type=tools`      | Models that call functions           |
| Vision     | `/models?type=vision`     | Models that read images              |
| Images     | `/models?type=image`      | Models that create images            |
| Embeddings | `/models?type=embeddings` | Models that turn text into vectors   |

Add `q=` to search and `provider=` to filter by maker: `/models?type=tools&provider=anthropic`.

## Match the model to the endpoint

| Model type                     | Endpoint                                                                                                                                         |
| ------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------ |
| Text, vision, reasoning, tools | [Chat completions](https://deference.si/docs/api-reference/chat-completions), [Messages](https://deference.si/docs/api-reference/messages) or [Responses](https://deference.si/docs/api-reference/responses) |
| Embeddings                     | [Embeddings](https://deference.si/docs/api-reference/embeddings)                                                                                                     |
| Image generation               | [Images](https://deference.si/docs/api-reference/images)                                                                                                             |

Coding tools pick the endpoint themselves: Claude Code uses Messages, Codex uses Responses, and most other tools use Chat completions.

## Read the price

Prices are in dollars per million tokens, with separate prices for input, output and cached input. Some models also charge per request or per image. A price is OpenRouter's price plus OpenRouter's 5% crypto platform fee, with no Deference markup. See [Pricing](https://deference.si/docs/concepts/pricing-and-metering).

[Free credit](https://deference.si/docs/concepts/free-credit) pays for open-weight text models whose output costs at most $2 per million tokens. Every other model needs credit.

## List models from the API

`GET /v1/models` needs no key and returns each model's id, context window, prices and supported parameters. See [Models](https://deference.si/docs/api-reference/models).

```bash
curl https://deference.si/v1/models
```

## Use aliases and suffixes

* Ids that start with `~` follow the newest model of a family.
* A trailing `[1m]` is accepted so Claude Code's context setting works. Deference ignores it when it looks up the model and its price, and forwards the id as you wrote it.

## If a model is missing

A model that is not in the catalog returns `404 model_not_found`. Providers retire models, so list models again and pick a current id.