App Logo
substack.com

Post Substack comment

Automatically post Substack comment on substack.com. Post a comment on a Substack post as the logged-in account. The account needs a display name set up on Substack first (via any post's comment box) — the script fails loudly with instructions if it isn't.

Input

url required

Full URL of the Substack post, e.g. https://example.substack.com/p/my-post-slug

text required

The comment text to post

Output

url required
text required
postId required
postedAt required
commentId required

FAQ

Post a comment on a Substack post as the logged-in account. The account needs a display name set up on Substack first (via any post's comment box) — the script fails loudly with instructions if it isn't.
Ask an AI agent connected to Reduck to run reduck/substack.com/post_comment, or run it from a terminal with the Reduck CLI: npx @reduck-ai/cli@latest run --script reduck/substack.com/post_comment
You do not need one. "Post Substack comment" drives the real substack.com pages in a browser, so it works whether or not substack.com offers an API for this.
Required: url, text.
It returns url, text, postId, postedAt, commentId.
Yes. It acts as you on substack.com: on your own Chrome it reuses your session, and on a Reduck-hosted browser it loads the substack.com cookies saved by the Reduck extension.
It makes changes on substack.com, like sending, posting, booking or buying something.
Ask an AI agent connected to Reduck to run reduck/substack.com/post_comment, or run it from a terminal with the Reduck CLI: npx @reduck-ai/cli@latest run --script reduck/substack.com/post_comment
It is part of Reduck's official curated catalogue.

Related scripts

substack.com

List Substack newsletter posts

List a Substack publication's posts from its archive, newest or top first, with optional keyword search and pagination. Returns each post's title, slug, publish date, paywall status, and reaction/comment/restack counts.

substack.com

Delete Substack comment

Delete one of the logged-in account's own comments on a Substack post, by the post URL and the comment's id (from post_comment or get_post_comments). Only your own comments can be deleted, and this cannot be undone.

substack.com

Subscribe to Substack publication

Subscribe the logged-in account to a Substack publication's free tier.

Start building not clicking

Get started for free