> For the complete documentation index, see [llms.txt](https://agpt.co/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://agpt.co/docs/integrations/block-integrations/attachments.md). # 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. *** --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://agpt.co/docs/integrations/block-integrations/attachments.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.