Send emails with attachments by songmeo · Pull Request #381 · taylorwilsdon/google_workspace_mcp

songmeo · 2026-01-23T00:35:36Z

- Add export_format='pdf' option for Google Sheets in get_drive_file_download_url - Previously only supported csv and xlsx formats for Sheets - Update docstring and parameter documentation - Tested with production Google Sheet and confirmed working

- Add file path and base64 content attachment support - Auto-detect MIME types from file extensions - Support attachments in both send_gmail_message and draft_gmail_message - Accept attachments via 'path' (file path) or 'content' (base64) + 'filename' - Note: FastMCP schema generation issue prevents List[Dict] from appearing in MCP tool schema

Copilot

Pull request overview

This PR adds attachment support to Gmail operations and extends Google Sheets export capabilities to include PDF format.

Changes:

Added attachment support for sending Gmail messages and creating drafts, supporting both file paths (auto-encoded) and base64 content
Extended Google Sheets export to support PDF format in addition to existing XLSX and CSV options

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 5 comments.

File	Description
gmail/gmail_tools.py	Added attachment handling logic with support for file paths and base64 content, updated function signatures and documentation for `send_gmail_message` and `draft_gmail_message`
gdrive/drive_tools.py	Added PDF export support for Google Sheets in `get_drive_file_download_url`

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Copilot · 2026-01-23T17:21:03Z

    references: Optional[str] = Body(
        None, description="Optional chain of Message-IDs for proper threading."
    ),
+    attachments_json: Optional[str] = Body(


Parameter is named attachments_json but the actual parameter used in the function body is attachments (line 1077, 1092, 1107-1108). The parameter name should match what's used throughout the function.

Suggested change

attachments_json: Optional[str] = Body(

attachments: Optional[str] = Body(

Copilot · 2026-01-23T17:21:03Z

        subject (str): Email subject.
        body (str): Email body content.
        body_format (Literal['plain', 'html']): Email body format. Defaults to 'plain'.
+        attachments (List[Dict[str, str]]): Optional list of attachments. Each dict can contain:


Documentation describes a parameter named attachments, but the function signature declares attachments_json. These names should be consistent.

Suggested change

attachments (List[Dict[str, str]]): Optional list of attachments. Each dict can contain:

attachments_json (Optional[str]): Optional JSON array of attachments. Each element is a dict that can contain:

Copilot · 2026-01-23T17:21:04Z

    """
    logger.info(
-        f"[send_gmail_message] Invoked. Email: '{user_google_email}', Subject: '{subject}'"
+        f"[send_gmail_message] Invoked. Email: '{user_google_email}', Subject: '{subject}', Attachments: {len(attachments)}"


This will raise an error when attachments is None. The code attempts to call len() on a potentially None value. Should check if attachments exists before calling len(), e.g., len(attachments) if attachments else 0.

Suggested change

f"[send_gmail_message] Invoked. Email: '{user_google_email}', Subject: '{subject}', Attachments: {len(attachments)}"

f"[send_gmail_message] Invoked. Email: '{user_google_email}', Subject: '{subject}', Attachments: {len(attachments) if attachments else 0}"

Copilot · 2026-01-23T17:21:04Z

+                part.add_header(
+                    "Content-Disposition", f"attachment; filename={filename}"


The filename should be properly quoted and sanitized in the Content-Disposition header to prevent header injection attacks. Use f'attachment; filename=\"{filename}\"' with proper escaping or use email.utils.encode_rfc2231().

Suggested change

part.add_header(

"Content-Disposition", f"attachment; filename={filename}"

# Sanitize filename to prevent header injection and ensure valid quoting

safe_filename = (filename or "").replace("\r", "").replace("\n", "")

safe_filename = safe_filename.replace("\\", "\\\\").replace('"', r"\"")

part.add_header(

"Content-Disposition", f'attachment; filename="{safe_filename}"'

Copilot · 2026-01-23T17:21:04Z

+    attachments: List[Dict[str, str]] = Body(
+        default_factory=list,


Using default_factory=list creates a mutable default argument. This should be Body(default=None) or use Optional[List[Dict[str, str]]] with None as default, similar to the pattern used in send_gmail_message.

Suggested change

attachments: List[Dict[str, str]] = Body(

default_factory=list,

attachments: Optional[List[Dict[str, str]]] = Body(

default=None,

martinschenk · 2026-01-29T18:22:33Z

Hi! Really looking forward to this feature. We're using google_workspace_mcp extensively for email automation via Claude Code and attachment support would be a great addition. Thanks for the implementation @songmeo! 👍

songmeo · 2026-01-29T20:52:51Z

Thank you, @martinschenk. I’ve been using my fork with this feature for the past week, and it’s been working well for us. Looking forward to the code review.

…into songmeo/main

Copilot

Pull request overview

Copilot reviewed 2 out of 3 changed files in this pull request and generated 4 comments.

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Copilot · 2026-01-30T00:24:50Z

+                        logger.warning("Skipping attachment: missing filename")
+                        continue
+
+                    file_data = base64.urlsafe_b64decode(content_base64)


Using urlsafe_b64decode for user-provided base64 content is incorrect. The Gmail API uses urlsafe_b64encode for the final message encoding, but attachment content from users should be decoded using standard base64.b64decode. Use base64.b64decode(content_base64) instead to handle standard base64-encoded attachment content.

Suggested change

file_data = base64.urlsafe_b64decode(content_base64)

file_data = base64.b64decode(content_base64)

Copilot · 2026-01-30T00:24:51Z

+                    continue
+
+                # Create MIME attachment
+                part = MIMEBase(*mime_type.split("/"))


If mime_type contains more than one '/' character (though uncommon, it's possible with malformed input), split('/') will produce more than 2 elements, causing MIMEBase to receive too many arguments. Use mime_type.split('/', 1) to ensure only two parts (maintype and subtype) are extracted.

Suggested change

part = MIMEBase(*mime_type.split("/"))

main_type, sub_type = mime_type.split("/", 1)

part = MIMEBase(main_type, sub_type)

Copilot · 2026-01-30T00:24:51Z

+                safe_filename = (filename or "").replace("\r", "").replace("\n", "")
+                safe_filename = safe_filename.replace("\\", "\\\\").replace('"', r"\"")


The filename sanitization logic is duplicated as separate steps. Consider consolidating into a single chain or extracting to a helper function for better maintainability, especially if this sanitization logic needs to be updated or reused.

Suggested change

safe_filename = (filename or "").replace("\r", "").replace("\n", "")

safe_filename = safe_filename.replace("\\", "\\\\").replace('"', r"\"")

safe_filename = (

(filename or "")

.replace("\r", "")

.replace("\n", "")

.replace("\\", "\\\\")

.replace('"', r"\"")

)

Copilot · 2026-01-30T00:24:51Z

    ),
+    attachments: Optional[List[Dict[str, str]]] = Body(
+        None,
+        description='Optional list of attachments. Each can have: "path" (file path, auto-encodes), OR "content" (base64) + "filename". Optional "mime_type". Example: [{"path": "/path/to/file.pdf"}] or [{"filename": "doc.pdf", "content": "base64data", "mime_type": "application/pdf"}]',


The description should clarify that 'content' expects standard base64 encoding (not urlsafe). This helps API consumers understand the expected format for base64-encoded attachments.

Song Meo added 2 commits January 23, 2026 02:33

taylorwilsdon requested review from Copilot and taylorwilsdon and removed request for Copilot January 23, 2026 17:20

taylorwilsdon self-assigned this Jan 23, 2026

taylorwilsdon requested a review from Copilot January 23, 2026 17:20

Copilot AI reviewed Jan 23, 2026

View reviewed changes

Song Meo added 4 commits January 23, 2026 20:12

Fix attachment parameter type inconsistency in send_gmail_message

21bac3a

Address Copilot review: sanitize filename and fix mutable default

2266e7d

Fix docstring to match Optional type annotation for attachments

7a72465

Merge upstream/main: integrate Send As feature with attachment support

5df04b6

songmeo changed the title ~~Allow export Sheets with PDF and send emails with attachments~~ Send emails with attachments Jan 28, 2026

Merge branch 'main' into main

fe497a8

taylorwilsdon added 2 commits January 29, 2026 19:22

Merge branch 'main' of github.com:taylorwilsdon/google_workspace_mcp …

3246f21

…into songmeo/main

ruff

e99479b

taylorwilsdon requested a review from Copilot January 30, 2026 00:23

Copilot AI reviewed Jan 30, 2026

View reviewed changes

taylorwilsdon added 2 commits January 29, 2026 19:43

fixes

736f275

fixes

46eeeb6

taylorwilsdon merged commit cac3378 into taylorwilsdon:main Jan 30, 2026
4 checks passed

	attachments_json: Optional[str] = Body(
	attachments: Optional[str] = Body(

	attachments (List[Dict[str, str]]): Optional list of attachments. Each dict can contain:
	attachments_json (Optional[str]): Optional JSON array of attachments. Each element is a dict that can contain:

	f"[send_gmail_message] Invoked. Email: '{user_google_email}', Subject: '{subject}', Attachments: {len(attachments)}"
	f"[send_gmail_message] Invoked. Email: '{user_google_email}', Subject: '{subject}', Attachments: {len(attachments) if attachments else 0}"

		part.add_header(
		"Content-Disposition", f"attachment; filename={filename}"

		attachments: List[Dict[str, str]] = Body(
		default_factory=list,

	file_data = base64.urlsafe_b64decode(content_base64)
	file_data = base64.b64decode(content_base64)

	part = MIMEBase(*mime_type.split("/"))
	main_type, sub_type = mime_type.split("/", 1)
	part = MIMEBase(main_type, sub_type)

		safe_filename = (filename or "").replace("\r", "").replace("\n", "")
		safe_filename = safe_filename.replace("\\", "\\\\").replace('"', r"\"")

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martinschenk commented Jan 29, 2026

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