# List available slots (/docs/api-reference/scheduling-availability/list-scheduling-slots)

Starts an attendee can book between `start` and `end` (at most 62 days), as UTC instants to show in their own time zone. A host whose calendar can't be read isn't offered.

`GET https://api.coss.com/v1/scheduling/event_types/{event_type}/slots`

Authenticate with your API key as a bearer token (`Authorization: Bearer coss_test_…`). Responses are JSON with snake_case fields; errors are `{ error: { type, code, message, param?, issues?, request_id } }` (https://coss.com/docs/api-reference/errors.md).

## Path parameters

- `event_type` (string, required): The event type's id or uid.

## Query parameters

- `start` (string, required): An ISO 8601 instant with an offset.
- `end` (string, required): An ISO 8601 instant with an offset.
- `host` (string): Only this host's slots (id or uid).
- `duration_minutes` (integer, 5-1440)
- `attributes` (string): A JSON object narrowing a pool, such as `{"licensed_in":"CA"}`.

## Example request

TypeScript (the `coss` package):

```ts
import { Coss } from "coss";

const coss = new Coss({
  apiKey: process.env.COSS_API_KEY,
  baseUrl: "https://api.coss.com",
});

const { data, error } = await coss.scheduling.slots.list({
  value: "evtype_01kd2m9a0b1c2d3e4f5g6h7j8m",
}, {
  start: "2027-01-04T15:00:00.000Z",
  end: "2027-01-04T15:00:00.000Z",
});
```

HTTP:

```sh
curl -X GET "https://api.coss.com/v1/scheduling/event_types/evtype_01kd2m9a0b1c2d3e4f5g6h7j8m/slots?start=2027-01-04T15%3A00%3A00.000Z&end=2027-01-04T15%3A00%3A00.000Z" \
  -H "Authorization: Bearer $COSS_API_KEY"
```

## Response 200

The slots.

- `object` ("list", required)
- `data` (object[], required)
  - `start` (string, required)
  - `end` (string, required)
  - `hosts` (string[], required): Who could take it.
- `has_more` (false, required)

Example:

```json
{
  "object": "list",
  "data": [
    {
      "start": "2027-01-04T15:00:00.000Z",
      "end": "2027-01-04T15:30:00.000Z",
      "hosts": [
        "host_01kd2m9a0b1c2d3e4f5g6h7j8m"
      ]
    }
  ],
  "has_more": false
}
```

## Errors

- `400`: The `Coss-Version` header names an unknown API version (`invalid_api_version`).
- `401`: The API key is missing, invalid, revoked or expired (`authentication_error`).
- `403`: The API key lacks the permission this endpoint needs (`permission_error`), or its organization is suspended (`organization_suspended`).
- `404`: Nothing with this id or uid exists in the environment (`not_found`).
- `422`: The request failed validation (`validation_error`, see `issues`), or can't be done: see `code`.
- `429`: Too many requests with this API key (`rate_limited`), or too many requests with invalid keys from this address (`too_many_failed_authentications`). Retry after `Retry-After` seconds. Successful responses carry `RateLimit-Limit`, `RateLimit-Remaining` and `RateLimit-Reset` (seconds until the limit is fully restored).
- `500`: Unexpected server error (`api_error` / `internal_error`).
- `503`: The API key could not be verified right now; retry (`service_unavailable`).