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mail.google.com

Reply to Gmail thread

Automatically reply to Gmail thread on mail.google.com. Reply (or reply-all) inside an existing Gmail conversation, given its thread id or the conversation's link, so the reply stays in the same thread with the original subject and quoted history. Optionally add Cc recipients, attach one file, or schedule the reply for later. Returns whether it was sent or scheduled, the conversation id and subject, and for scheduled replies the time Gmail shows. To start a new conversation instead, use mail.google.com/send_email.

Input

body required

Plain-text reply body (newlines preserved). Long bodies are fine.

cc optional

Optional Cc address(es) added to the reply. A single string or an array of strings.

sendAt optional

Optional. Schedule the reply instead of sending it now: a local date and time with no offset (e.g. 2026-10-09T09:00), read in the browser's time zone. Must be at least a few minutes ahead.

account optional

Google account email to act as. Without it Gmail picks the first signed-in account, which may not be the one you expect if several accounts share the browser.

replyAll optional

Reply to all recipients instead of just the sender.

Default: false
threadId optional

Hex thread id as returned by search_emails, e.g. "19f2817451c27480". Give this or threadUrl.

threadUrl optional

The Gmail address of the conversation, as copied from the browser (e.g. https://mail.google.com/mail/u/0/#inbox/FMfcgz...). Give this or threadId.

attachment optional

Optional file to attach. From an agent: files: { attachment: { relativePath: "invoice.pdf" } }, a name inside the reduck folder on the Desktop. From the CLI: file:attachment=/path/to/file.

attachmentName optional

Filename the recipient sees, with its extension. Defaults to the file's own name.

Output

sent required

True when the reply went out now. False when it was scheduled instead.

replyAll required
threadId required

Hex id of the conversation the reply was added to.

cc optional
subject optional

Subject of the conversation the reply joined.

scheduled optional
attachment optional
scheduledFor optional

The send date and time as Gmail shows it on the Scheduled list, in the account's language.

foundInScheduled optional

FAQ

Reply (or reply-all) inside an existing Gmail conversation, given its thread id or the conversation's link, so the reply stays in the same thread with the original subject and quoted history. Optionally add Cc recipients, attach one file, or schedule the reply for later. Returns whether it was sent or scheduled, the conversation id and subject, and for scheduled replies the time Gmail shows. To start a new conversation instead, use mail.google.com/send_email.
Ask an AI agent connected to Reduck to run reduck/mail.google.com/reply_to_email, or run it from a terminal with the Reduck CLI: npx @reduck-ai/cli@latest run --script reduck/mail.google.com/reply_to_email
You do not need one. "Reply to Gmail thread" drives the real mail.google.com pages in a browser, so it works whether or not mail.google.com offers an API for this.
Required: body. Optional: cc, sendAt, account, replyAll, threadId, threadUrl, attachment, attachmentName.
It returns cc, sent, subject, replyAll, threadId, scheduled, attachment, scheduledFor, foundInScheduled.
Yes. It acts as you on mail.google.com: on your own Chrome it reuses your session, and on a Reduck-hosted browser it loads the mail.google.com cookies saved by the Reduck extension.
It makes changes on mail.google.com, like sending, posting, booking or buying something.
Ask an AI agent connected to Reduck to run reduck/mail.google.com/reply_to_email, or run it from a terminal with the Reduck CLI: npx @reduck-ai/cli@latest run --script reduck/mail.google.com/reply_to_email
It is part of Reduck's official curated catalogue.

Related scripts

mail.google.com

Search Gmail

Search the signed-in Gmail with the native query syntax (from:, to:, subject:, has:attachment, after:/before:, labels…) and return matching threads: threadId (feed it to get_thread / reply_to_email), sender, senderEmail, subject, snippet, date, unread, starred, hasAttachment. Results are threads rather than individual messages, which is Gmail's own search granularity, and only the first page of results is returned (up to 50).

mail.google.com

Send Gmail email

Send an email from the signed-in Gmail account, with a plain-text body and an optional single file attachment. Always starts a new conversation. To answer inside an existing thread, use mail.google.com/reply_to_email.

mail.google.com

Get Gmail thread

Read a Gmail thread by its hex threadId (as returned by search_emails): subject plus every rendered message's from, fromEmail, to, date, plain-text body and attachment names. In long threads Gmail collapses older messages, so only rendered (expanded) messages are returned.

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