---
title: "Stage a file for a draft"
method: POST
path: "/api/v1/rest/email/attachments"
tags: ["Email & PEC"]
---

# Stage a file for a draft

`POST /api/v1/rest/email/attachments`

## Request

- Base URL: `https://api.custodo.ai`
- URL: `https://api.custodo.ai/api/v1/rest/email/attachments`
- Auth: HTTP bearer

Uploads a file as base64 and stores it content-addressed, WITHOUT attaching it to anything yet. Returns a `sha256` (plus filename, content_type, size_bytes and — for `inline: true` — a `content_id`): pass those in the `attachments` array of email_update_draft to actually name it on a draft (email_draft itself does not accept attachments). Accepts up to 8 MB decoded; anything larger belongs in the web app.

## Headers

- `X-Tenant-Id` string, uuid

## Request body

- object
  - `filename` string, required
  - `content_base64` string, required: The file’s bytes, base64-encoded.
  - `content_type` string
  - `inline` boolean: true to embed as `<img src="cid:…">` rather than attach as a file.

## Response `200`

Done. `data` is the tool’s own answer.

- RestResult
  - `ok` true, required
  - `data` unknown, required

## Other responses

- `400`: The arguments did not validate: `error.message` names the field, what it expects and what arrived.
- `401`: No API key, or one that is malformed, unknown, revoked or expired.
- `403`: The call never ran: the module is off for this organisation, the credential lacks the permission or the module, the tier does not cover it, or the tool is destructive and the key was not minted for that.
- `409`: The record is in a state that does not allow it — under legal hold, already sent, already closed. `error.code` says which.
- `422`: The tool ran and refused, in a sentence of its own (`TOOL_REFUSED`): the message says what to change. Retrying the same call will not help.
- `429`: The API key has spent its minute, or its day. Every request a key makes counts. See `Retry-After`.

---

[API](https://skmtc.dev/custodo/apis/custodo-integrazioni.md) · [All operations](https://skmtc.dev/custodo/apis/custodo-integrazioni/llms.txt) · [OpenAPI document](https://skmtc.dev/custodo/apis/custodo-integrazioni/revisions/16d336d3ec2a?raw)