For AI agents: a documentation index is available at the root level at /llms.txt and /llms-full.txt. Append /llms.txt to any URL for a page-level index, or .md for the markdown version of any page.
In this document, we will explain how to add a single or multiple attachments in your email.
You can add static as well as dynamic attachments to emails
There is no limit to the number of attachments. However, maximum size of the attachment(s) should be 10MB. We support the following file extensions: .jpg, .jpeg, .png, .gif, .pdf, .mp4, .doc, .docx, .xls and .xlsx
On clicking on the attach button (highlighted below) on the to right corner of the either Email editor, you will see:
Upload Files: Allows you to attach files from the system. This then stays as a static attachment in the body of the email and is sent along with the email as an attachment every time it’s triggered.
Dynamic Placeholders: Allows you to include dynamic files within the email, when the notification event is triggered. You can use placeholders to specify the:
File Name - Provide a static value like ‘Invoice.pdf’ (if you are testing it manually) or a placeholder like {{attachment.filename}}(if your are triggering notification event via API)
Type - Select the file type from the dropdown or you can enter a placeholder like {{attachment.filetype}} You can see all the MIME types here
URL - Provide a static URL or Dynamic URL using a placeholder like {{attachment.presigned_url}}. The URL should be wither pre-signed or public URL.
Please note that if you are using Presigned S3 URL, then the URL should trigger a download of the file immediately when opened.
Placeholders should be used if the attachment information is dynamic (for instance, a personalized attachment depending on the recipient). Typically such attachments are sent via an API call. To send dynamic attachments in the event payload, make sure that the data section of the payload has an object called attachment as shown below.
For file type, use MIME types depending on your attachment’s file type
Send Attachment via Email
1
curl -X POST 'https://api.fyno.io/v1/<WorkspaceID>/event' \
2
-H 'Authorization: Bearer <API_KEY>' \
3
-H 'Content-Type: application/json' \
4
-d '{
5
"event": "EmailWithAttachments",
6
"to": {
7
"email": "xyz@gmail.com"
8
},
9
"data": {
10
"attachment":
11
{
12
"presigned_URL": "<presigned_URL>",
13
"filename": "<attachment_file_name>",
14
"filetype": "application/pdf"
15
}
16
}
17
}'
In the above command:
1Replace <WorkspaceID> with your actual Workspace ID.
4You can keep adding as many files. The total file size should not exceed 10MB.
Please note that the content can be base64-encoded content or a Presigned URL
Configuring File Attachments Using Fixed Mode
Fixed Mode is used when the number of files is predefined and does not change at runtime.
You manually configure each file (File 1, File 2, etc.) by specifying its name, MIME type, and URL individually.
When to Use Fixed Mode
Use Fixed Mode when:
The number of files is known in advance.
The same files are sent to all users.
Files are static (for example, brochure, invoice template, product catalog).
You need full control over each file configuration.
Example Static Configuration
File 1
File Name:invoice.pdf
MIME Type:application/pdf
URL:https://example.com/invoice.pdf
File 2
File Name:coupon.jpg
MIME Type:image/jpeg
URL:https://example.com/coupon.jpg
Result:
Both files will always be attached exactly as configured.
Fields Explained
Field
Purpose
How to Configure
Example
Number of Files
Defines how many files will be attached.
Select Fixed and manually add each file.
—
File Name
Specifies the name shown to the user.
Enter a static file name or placeholder.
invoice.pdf
MIME Type
Defines the file type being sent (must be valid MIME type).
Select from dropdown or enter a valid value (e.g., image/png, application/pdf).
application/pdf, image/jpeg
URL
Specifies the file location.
Enter a publicly accessible URL or a valid pre-signed URL.
https://example.com/file.pdf
Important Notes
Each file must be configured separately.
The URL must be publicly accessible or pre-signed.
The MIME type must be valid (for example, application/pdf, image/png).
The number of files will remain fixed for every execution.
If the file count needs to vary dynamically, use Dynamic Mode instead.
Sample Configuration Summary
If you configure:
File
File Name
MIME Type
URL
File 1
product_catalog.pdf
application/pdf
https://example.com/catalog.pdf
File 2
pricing_sheet.pdf
application/pdf
https://example.com/pricing.pdf
Result:
2 files will always be attached:
product_catalog.pdf
pricing_sheet.pdf
Configuring File Attachments Using Dynamic Mode
Dynamic mode is used when the number of files is not fixed and is provided at runtime as a JSON array (for example, from a previous step’s output).
Instead of manually adding File 1, File 2, File 3, and so on, you define mappings that tell the system:
“For each item in this array, get the file name from here and the URL from there.”
When to Use Dynamic Mode
Use Dynamic mode when:
The number of files varies per execution.
Files come from an API response, loop, or previous ste.
You don’t know in advance how many files there will be.
Dynamic File Attachment Fields
This section explains all fields used to configure dynamic file attachments.
Field
Purpose
How to Configure
Example
Number of Files
Enables array-based (dynamic) file creation.
Select Dynamic.
—
File Mapper
Defines one template mapping that applies to every item in the array.
Configure once; the system automatically applies it to all items.
—
File Name (Dynamic)
Specifies where to get the file name for each item.
Reference the array item using a placeholder.
{{files.0.filename}} or {{array_path.0.filename}}
MIME Type
Specifies the type of file being attached.
Reference a placeholder that resolves to a valid MIME type (not a file extension).
