---
title: "Upload the e-mail signature image"
method: POST
path: "/v1/account/signature"
tags: ["Account"]
---

# Upload the e-mail signature image

`POST /v1/account/signature`

## Request

- Base URL: `https://api.briefgate.dev`
- URL: `https://api.briefgate.dev/v1/account/signature`
- Auth: HTTP bearer

**Session only.** Multipart body with one field, `file`: PNG, JPEG or WebP, up to 2 MB. The image is re-encoded as PNG (at most 600 px wide, aspect ratio kept, EXIF and metadata stripped) and served from `GET /v1/branding/{accountId}/signature`; that URL becomes the account's `brand_signature_url`. Rendered at the bottom of every client-facing mail this account sends. Upload only — there is no pasted-URL form. Requires custom branding (Solo plan or higher, `402 plan_required` with reason `custom_branding` otherwise).

## Response `201`

Signature image stored

- object
  - `brand_signature_url` string, uri

## Other responses

- `401`: Missing or invalid API key
- `402`: The account's plan does not include this — `plan_required` — or a quota is exhausted
- `422`: Empty, oversized or unreadable file, or a type other than the three accepted.

---

[API](https://skmtc.dev/briefgate/apis/briefgate-api.md) · [All operations](https://skmtc.dev/briefgate/apis/briefgate-api/llms.txt) · [OpenAPI document](https://skmtc.dev/briefgate/apis/briefgate-api/revisions/b21afed4748b?raw)