---
title: "Reply in a thread"
method: POST
path: "/inboxes/{id}/threads/{threadId}/reply"
tags: ["Inboxes"]
---

# Reply in a thread

`POST /inboxes/{id}/threads/{threadId}/reply`

## Request

- Base URL: `https://sending.dev/api/v1`
- URL: `https://sending.dev/api/v1/inboxes/{id}/threads/{threadId}/reply`
- Auth: HTTP bearer

Required scope: `inbox:send`. (`inbox:*` scopes cannot be assigned from the UI: they require a full-access `*` key).

## Path parameters

- `id` string, required: Inbox ID.
- `threadId` string, required: Thread ID.

## Request body

- ReplyInput
  - `html` string, required
  - `cc` union: One or more recipients: 'a@b.com', 'Name <a@b.com>', several comma-separated addresses, or an array.
    - string
    - string[]
  - `bcc` union: One or more recipients: 'a@b.com', 'Name <a@b.com>', several comma-separated addresses, or an array.
    - string
    - string[]
  - `attachments` object[]: Email attachments (max 20, 10 MB each, 25 MB in total). For each item provide exactly one source: `id`, `content` (base64) or `url`.
    - `id` string, uuid: Id of an attachment already uploaded with POST /v1/attachments.
    - `filename` string: File name shown to the recipient. Required with `content` or `url`.
    - `content` string: File content in base64, without the `data:` prefix.
    - `url` string, uri: Public https URL to download the file from (private hosts are blocked).
    - `contentType` string: Content-Type override; when absent, it is inferred from the file name.
    - `contentId` string: Content-ID for inline images referenced in the HTML as `cid:<value>`: the attachment becomes `inline` instead of appearing at the end of the message.
  - `idempotencyKey` string

## Response `202`

Reply queued.

- SendResult
  - `id` string
  - `status` string, required
  - `idempotencyKey` string

## Other responses

- `401`: Missing or invalid token.
- `403`: Insufficient scope.
- `404`: Resource not found.
- `422`: Invalid input.

---

[API](https://skmtc.dev/sending/apis/sending-dev-api.md) · [All operations](https://skmtc.dev/sending/apis/sending-dev-api/llms.txt) · [OpenAPI document](https://skmtc.dev/sending/apis/sending-dev-api/revisions/9fe78d2918a1?raw)