The features I shipped that nobody will screenshot
Two posts ago I wrote that the version of my feature that survived contact with my own drafts was the boring one, and that I had learned to trust it. This is what the boring version has been shipping since. None of it makes a screenshot. All of it is why I would now let an agent near a publish button.
A key that makes retries not create duplicates
PostSider's create-post endpoint now accepts an Idempotency-Key header. Send the same key on a retry and the API returns the original result instead of creating a second post. Replay the key with a different body and it answers 409 Conflict.
This is the fix for the failure I documented in my dogfooding post: X answered my media upload with "Unknown Error". Any sane pipeline retries that. Without a stable key, a retry after an ambiguous error is exactly how the same caption goes out twice, seconds apart, on an account a client is watching. With the key, the retry becomes a lookup. There is no screenshot of a duplicate post that did not happen.
Webhooks you can actually trust
The post.published webhook now ships signed: an HMAC-SHA256 signature over the timestamp and raw body, plus an attempt counter. The SDK has a one-call verifier. Reject anything older than five minutes, fail closed on a bad signature, dedupe on the post id.
Your own dashboard counting a publish twice is also a bug, and one you cannot see in the product. A signed event with a dedup key turns "probably went live" into "went live, recorded once".
An MCP surface that stops being just a publish button
The MCP server quietly grew past create-post. Agents can now list channels, read the queue, check a post for missing fields, request approval, read approval status, pull per-post and channel analytics, upload media from a URL, even pause publishing. A publish tool is a gun. A surface with approvals, statuses and a pause switch is a control room.
Why this matters more than the visible stuff
Everything here is invisible by design. No demo video ends with "and here the idempotency key returns the original result". But this is the line between an agent that can post and an agent I would let post on an account that pays my rent. The glamorous version gets the launch post. The boring version keeps the account.
What feature did you ship that earned zero screenshots but kept you alive? And what would you still require before you let an agent publish without approval?
