Agent Mail Attachments

Blocks for downloading file attachments from AgentMail messages and threads. Attachments are files associated with messages (PDFs, CSVs, images, etc.) and are returned as base64-encoded content.

Agent Mail Get Message Attachment

What it is

Download a file attachment from an email message. Returns base64-encoded file content.

How it works

The block calls the AgentMail API's inboxes.messages.get_attachment endpoint using the provided inbox ID, message ID, and attachment ID. The API returns the raw file content, which may arrive as bytes or str depending on the attachment type. The block base64-encodes the result: binary data is encoded directly, while string data is first UTF-8 encoded then base64-encoded. If the API returns an unexpected data type, the block raises a TypeError.

On any failure — invalid IDs, network errors, authentication issues, or unexpected response types — the block catches the exception and yields the error message on the error output instead of content_base64. No partial results are returned; the block either yields both content_base64 and attachment_id on success, or only error on failure.

Inputs

Input	Description	Type	Required
inbox_id	Inbox ID or email address the message belongs to	str	Yes
message_id	Message ID containing the attachment	str	Yes
attachment_id	Attachment ID to download (from the message's attachments array)	str	Yes

Outputs

Output	Description	Type
error	Error message if the operation failed	str
content_base64	File content encoded as a base64 string. Decode with base64.b64decode() to get raw bytes.	str
attachment_id	The attachment ID that was downloaded	str

Possible use case

Invoice Processing Pipeline — Download PDF invoices from incoming messages and feed them into a parsing block that extracts line items and totals. Automated Attachment Archival — Pull attachments from specific senders and store the base64 content in a database or cloud bucket for long-term retention. Image Analysis Workflow — Retrieve image attachments from support emails and pass them to a vision model block for classification or OCR.

---

Agent Mail Get Thread Attachment

What it is

Download a file attachment from a conversation thread. Returns base64-encoded file content.

How it works

The block calls the AgentMail API's inboxes.threads.get_attachment endpoint using the provided inbox ID, thread ID, and attachment ID. This is functionally identical to the message attachment block but resolves the attachment via a thread rather than a specific message — useful when you have the thread context but not the individual message ID. The raw response is base64-encoded the same way: bytes are encoded directly, str is UTF-8 encoded first, and any other response type triggers a TypeError.

Error handling follows the same all-or-nothing pattern: on success the block yields content_base64 and attachment_id; on any exception (bad IDs, auth failure, network error, unexpected type) it yields only error with the exception message.

Inputs

Input	Description	Type	Required
inbox_id	Inbox ID or email address the thread belongs to	str	Yes
thread_id	Thread ID containing the attachment	str	Yes
attachment_id	Attachment ID to download (from a message's attachments array within the thread)	str	Yes

Outputs

Output	Description	Type
error	Error message if the operation failed	str
content_base64	File content encoded as a base64 string. Decode with base64.b64decode() to get raw bytes.	str
attachment_id	The attachment ID that was downloaded	str

Possible use case

Conversation Attachment Collector — Iterate over a support thread and download every attachment to build a complete case file for review. Threaded Report Extraction — Pull CSV or Excel attachments from recurring report threads and forward them to a data-processing block. Compliance Document Retrieval — Download signed-document attachments from legal threads and pass them to a verification or archival workflow.

---