Email Attachments

Attach files — PDFs, images, spreadsheets, and more — to any email by including an attachments array on the Send Email request. Files are Base64-encoded and sent inline with the message.

Endpoint

Attachments are part of the standard send request:

POST /v1/email/send

Attachment Object

Field	Type	Required	Description
filename	string	Yes	Name shown to the recipient (e.g. invoice-12345.pdf)
content	string	Yes	Base64-encoded file contents
content_type	string	Yes	MIME type (e.g. application/pdf)
disposition	string	No	attachment (default) or inline
content_id	string	No	CID for inline images referenced in HTML

Limits

Constraint	Value
Max single attachment	10 MB
Max total message size	25 MB
Max attachments per email	20

Exceeding these returns ATTACHMENT_TOO_LARGE.

Send With an Attachment

curl -X POST https://api.afriroute.ai/api/v1/email/send \
  -H "Authorization: Bearer $AFRIROUTE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "[email protected]",
    "to": "[email protected]",
    "subject": "Invoice #12345",
    "html": "<p>Please find your invoice attached.</p>",
    "attachments": [
      {
        "filename": "invoice-12345.pdf",
        "content": "JVBERi0xLjQKJ...",
        "content_type": "application/pdf"
      }
    ]
  }'

Code Samples

send-attachment.js

import fs from 'fs';

const pdf = fs.readFileSync('invoice-12345.pdf').toString('base64');

await fetch('https://api.afriroute.ai/api/v1/email/send', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer $AFRIROUTE_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    from: '[email protected]',
    to: '[email protected]',
    subject: 'Invoice #12345',
    html: '<p>Please find your invoice attached.</p>',
    attachments: [
      {
        filename: 'invoice-12345.pdf',
        content: pdf,
        content_type: 'application/pdf'
      }
    ]
  })
});

send_attachment.py

import base64
import requests

with open('invoice-12345.pdf', 'rb') as f:
    pdf = base64.b64encode(f.read()).decode()

requests.post(
    'https://api.afriroute.ai/api/v1/email/send',
    headers={'Authorization': 'Bearer $AFRIROUTE_API_KEY'},
    json={
        'from': '[email protected]',
        'to': '[email protected]',
        'subject': 'Invoice #12345',
        'html': '<p>Please find your invoice attached.</p>',
        'attachments': [{
            'filename': 'invoice-12345.pdf',
            'content': pdf,
            'content_type': 'application/pdf'
        }]
    }
)

Inline Images

Reference an embedded image from your HTML using a content_id and the cid: scheme.

{
  "from": "[email protected]",
  "to": "[email protected]",
  "subject": "Our New Logo",
  "html": "<p>Check out our new logo:</p><img src=\"cid:logo\" alt=\"Logo\">",
  "attachments": [
    {
      "filename": "logo.png",
      "content": "iVBORw0KGgoAAAANS...",
      "content_type": "image/png",
      "disposition": "inline",
      "content_id": "logo"
    }
  ]
}

Common MIME Types

Extension	content_type
.pdf	application/pdf
.png	image/png
.jpg	image/jpeg
.csv	text/csv
.xlsx	application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
.zip	application/zip

Best Practices

• Keep attachments small — link to large files instead of attaching them when possible.
• Set the correct content_type so clients render or download files properly.
• Use inline images sparingly; many clients block remote and embedded images by default.
• Avoid executable types (.exe, .bat) — they are commonly blocked or quarantined.
• Base64 inflates size ~33% — account for this against the 25 MB total limit.

Errors

Code	HTTP	Meaning
ATTACHMENT_TOO_LARGE	413	A file or the total message exceeds limits
INVALID_ATTACHMENT	400	Missing content, filename, or content_type
BLOCKED_FILE_TYPE	415	The attachment type is not permitted

Related Resources

• Send Email
• Email Overview
• Templates

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Last Updated: May 2026 · Need help? Contact Support →