# List an inbox's messages (/docs/api-reference/inboxes/list-inbox-messages)

Messages of every thread, newest first, with a preview instead of their bodies (retrieve one for those). Pass the last `id` as `after` to get the next page while `has_more` is true.

`GET https://api.coss.com/v1/inboxes/{inbox_id}/messages`

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

- `inbox_id` (string, required): The inbox's id.

## Query parameters

- `limit` (integer, 1-100): 1-100, default 20.
- `after` (string, at most 64 characters): Cursor: the `id` of the last item of the previous page.
- `direction` ("inbound" | "outbound"): Only inbound (received) or outbound (sent) messages.

## 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.inboxes.messages.list("inbox_01k7c8m4q2f3e9v6t5r1n0p8yz");
```

HTTP:

```sh
curl -X GET "https://api.coss.com/v1/inboxes/inbox_01k7c8m4q2f3e9v6t5r1n0p8yz/messages" \
  -H "Authorization: Bearer $COSS_API_KEY"
```

## Response 200

A page of messages.

- `object` ("list", required)
- `data` (object[], required)
  - `object` ("inbox_message", required)
  - `id` (string, required)
  - `inbox_id` (string, required)
  - `thread_id` (string, required)
  - `direction` ("inbound" | "outbound", required): `inbound`: received by the inbox. `outbound`: sent from it.
  - `status` ("received" | "queued" | "sent" | "failed" | "scheduled" | "canceled", required): `received` for inbound messages; an outbound message's email status (`queued`, `sent`, `failed`, …): its email has each recipient's delivery.
  - `from` (string | null, required): The `From` header.
  - `to` (string[], required)
  - `cc` (string[], required)
  - `subject` (string | null, required)
  - `preview` (string | null, required): The start of the message's own text (without the quoted conversation).
  - `attachments` (object[], required): An inbound message's attachments (download them from the message).
    - `id` (string, required)
    - `filename` (string | null, required): `null` when the part named none.
    - `content_type` (string, required)
    - `content_id` (string | null, required): Set for parts the HTML references (`cid:` URLs).
    - `disposition` ("attachment" | "inline", required)
    - `size` (integer, required): Size in bytes.
  - `spam` (boolean, required): Whether the receiving server judged it spam.
  - `received_email_id` (string | null, required): The received email of an inbound message.
  - `email_id` (string | null, required): The email of an outbound message: its delivery events and webhooks name it.
  - `created_at` (string, required, date-time): When it was received or sent.
- `has_more` (boolean, required)

Example:

```json
{
  "object": "list",
  "data": [
    {
      "object": "inbox_message",
      "id": "imsg_01k7c8m4s1d3c9x0z4e6g7h8j9",
      "inbox_id": "inbox_01k7c8m4q2f3e9v6t5r1n0p8yz",
      "thread_id": "thread_01k7c8m4r0c2b8w9y3d5f6g7h8",
      "direction": "inbound",
      "status": "received",
      "from": "Jane Doe <jane@example.com>",
      "to": [
        "support-agent@k3j9x2m7qp4l.inbound.coss.com"
      ],
      "cc": [],
      "subject": "My order arrived damaged",
      "preview": "Hi, the order arrived damaged. Can you send a new one?",
      "attachments": [
        {
          "id": "rcvdatt_01k7c8m4r0c2b8w9y3d5f6g7h8",
          "filename": "photo.jpg",
          "content_type": "image/jpeg",
          "content_id": null,
          "disposition": "attachment",
          "size": 48213
        }
      ],
      "spam": false,
      "received_email_id": "rcvd_01k7c8m4q2f3e9v6t5r1n0p8yz",
      "email_id": null,
      "created_at": "2026-10-10T12:00:00.000Z"
    }
  ],
  "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`: No inbox with this id exists in this environment. (`not_found`)
- `422`: A query parameter failed validation (`validation_error`).
- `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`).