---
title: "Update an inbox reply draft"
method: PATCH
path: "/mailboxes/{id}/inbox/threads/{thread_id}/drafts/{draft_id}"
tags: ["Mailboxes", "Messages"]
---

# Update an inbox reply draft

`PATCH /mailboxes/{id}/inbox/threads/{thread_id}/drafts/{draft_id}`

## Request

- Base URL: `https://shipmail.to/api/v1`
- URL: `https://shipmail.to/api/v1/mailboxes/{id}/inbox/threads/{thread_id}/drafts/{draft_id}`
- Auth: one of:
  - HTTP bearer
  - OAuth 2 (authorization code, authorization URL `https://shipmail.to/api/auth/oauth2/authorize`, token URL `https://shipmail.to/api/auth/oauth2/token`)

Replace the body of a reply draft in status draft. The new body replaces the old one: html alone derives the text part; text alone makes a plain-text draft. Recipients, subject and reply headers stay derived from the source message, and the draft ID stays the same. Returns 409 conflict when the status is not draft, when the thread changed since expected_version (the draft becomes invalidated; create a new draft from a fresh thread read), when the draft changed concurrently, or when the draft belongs to the Shipmail Assistant. Returns 422 when html keeps no text or image and no text is given. Supported HTML tags: p, br, strong/b, em/i, u, s, a (http, https, mailto, tel), ul, ol, li, blockquote, code, pre, h2, h3, span/mark with the composer's styles, and inline cid: images. h1 becomes h2. Tables and h4-h6 are not supported: their text stays as paragraphs and removed_formatting lists them ("table" for any table part, "h4", ...), as it lists other dropped elements such as script, style or iframe. Attributes and inline styles outside the composer set are dropped and not reported. Paragraphs are spaced like the Shipmail composer, so do not add <p><br></p> between them. When html is given without text, the text part is derived from it.

## Headers

- `X-Shipmail-Organization` string

## Request body

- union: The new body replaces the old one. html alone derives the text part; text alone makes a plain-text draft. Recipients, subject and reply headers stay derived from the source message.
  - object
    - `text` string, required: Plain text body. At least one of html or text is required.
    - `html` string: HTML body. At least one of html or text is required. Supported HTML tags: p, br, strong/b, em/i, u, s, a (http, https, mailto, tel), ul, ol, li, blockquote, code, pre, h2, h3, span/mark with the composer's styles, and inline cid: images. h1 becomes h2. Tables and h4-h6 are not supported: their text stays as paragraphs and removed_formatting lists them ("table" for any table part, "h4", ...), as it lists other dropped elements such as script, style or iframe. Attributes and inline styles outside the composer set are dropped and not reported. Paragraphs are spaced like the Shipmail composer, so do not add <p><br></p> between them. When html is given without text, the text part is derived from it.
  - object
    - `text` string: Plain text body. At least one of html or text is required.
    - `html` string, required: HTML body. At least one of html or text is required. Supported HTML tags: p, br, strong/b, em/i, u, s, a (http, https, mailto, tel), ul, ol, li, blockquote, code, pre, h2, h3, span/mark with the composer's styles, and inline cid: images. h1 becomes h2. Tables and h4-h6 are not supported: their text stays as paragraphs and removed_formatting lists them ("table" for any table part, "h4", ...), as it lists other dropped elements such as script, style or iframe. Attributes and inline styles outside the composer set are dropped and not reported. Paragraphs are spaced like the Shipmail composer, so do not add <p><br></p> between them. When html is given without text, the text part is derived from it.

## Response `200`

Updated reply draft.

- InboxReplyDraftWrite: A reply draft returned by create and update, with the formatting the HTML sanitiser dropped.
  - `object` 'inbox_reply_draft', required
  - `id` string, required
  - `mailbox_id` string, required
  - `thread_id` string, required: Deprecated and not stable: a legacy thread ID that changes when the mail server re-threads its IDs or a relayed send's placeholder key is replaced. It remains supported in thread paths; store conversation_id instead.
  - `conversation_id` string, required: Stable Shipmail conversation identifier (thd_...). Store this: it survives thread merges and mail-server re-threading, which thread_id does not.
  - `based_on_message_id` string, nullable, required
  - `expected_version` integer, required
  - `reply_mode` 'reply' | 'reply_all', required
  - `status` 'draft' | 'sending' | 'sent' | 'invalidated' | 'failed', required
  - `to` object[], required: Recipients derived from the source message. Empty, like cc, once the stored draft no longer exists.
    - `address` string, email, required
    - `name` string, nullable, required
  - `cc` object[], required
    - `address` string, email, required
    - `name` string, nullable, required
  - `subject` string, nullable, required: Stored subject. Null once the stored draft no longer exists (after a send or cleanup).
  - `html` string, nullable, required: Stored HTML after sanitisation. Null once the stored draft no longer exists.
  - `text` string, nullable, required: Stored text part. Null once the stored draft no longer exists.
  - `sent_message_id` string, nullable, required: ID of the sent message once the draft is sent.
  - `created_at` string, date-time, required
  - `updated_at` string, date-time, required
  - `sent_at` string, date-time, nullable, required
  - `removed_formatting` string[], required: Formatting the HTML sanitiser dropped: "table" for any table part, "h4" to "h6", and other dropped elements such as "script". Their text stays as paragraphs. Empty when nothing was dropped.

## Other responses

- `401`: Authentication failed.
- `403`: Insufficient permissions.
- `404`: Resource not found.
- `409`: Resource conflict.
- `422`: Validation failed.
- `429`: Rate limit exceeded.

---

[API](https://skmtc.dev/shipmail/apis/shipmail-api.md) · [All operations](https://skmtc.dev/shipmail/apis/shipmail-api/llms.txt) · [OpenAPI document](https://skmtc.dev/shipmail/apis/shipmail-api/revisions/2c23e59d7e30?raw)