Announcement Bar
by
Banner copy for ecommerce teams: decide what the bar should say today from stock, shipping cutoffs and what is actually converting, then update it.
The announcement bar is the one element on every page of the store, and it usually says the same thing it said in March. It keeps promoting a sale that ended, or a free shipping threshold that no longer matches the basket distribution, or nothing at all. Nobody updates it because it is small and there is no obvious owner. Meanwhile it is the most seen sentence on the site. This skill decides what the bar should say today from current stock, shipping cutoffs and what has actually converted, then updates the copy.
What It Does
- Reads the active offers, cutoffs and stock positions worth announcing today.
- Measures which past bar messages actually moved conversion, not just clicks.
- Checks the threshold in the copy against your current basket distribution.
- Retires a message the moment its underlying reason expires.
- Writes one sentence, short enough to survive a phone screen.
- Updates the banner copy, with the reason it changed recorded.
Use Cases
- Stop running a sale message two weeks after the sale ended.
- Announce a shipping cutoff on the day it starts to matter.
- Match the free shipping line to the threshold you actually run.
- Give the most viewed sentence on the site an owner.
Example Session
What should the announcement bar say today?
Swap the sale message for the shipping cutoff. The sale ended nine days ago.
- Candidate | Reason it applies today | Lift when last run | Verdict
- Winter sale, 25% off | Ended Mar 3 | n/a | Remove now
- Free shipping over $85 | Matches current threshold | +2.1% | Hold in reserve
- Order by Thu for weekend delivery | Cutoff is Thursday | +3.4% | Run today
- Navy jacket back in stock | Restocked Monday | +1.2% | Run Friday
The expired sale line is the worst of the four, because a shopper who clicks it finds full prices and reads that as a bait. The cutoff message is time-bound, true, and historically your strongest bar. Run it Tuesday through Thursday, then switch to the restock on Friday when the cutoff no longer applies.
Why This Beats Prompting It Yourself
A Permanent Banner vs A Message With An Expiry Date: The Hidden Risk
A generic prompt writes a good banner sentence and stops there, because writing the sentence is the task as posed. It has no view of whether the sale it promotes is still running. An expired offer in the announcement bar is worse than an empty bar: the shopper clicks, finds full price, and now has a reason to distrust everything else on the page.
When You Still Need The Reason To Expire
Every message the skill writes carries the condition that makes it true and the date it stops being true. That is what turns the bar from a decoration into something that can be maintained without anyone remembering to. A banner nobody owns defaults to whatever was correct on the day it was written.
Known Limitations
Lift per message needs enough runs to separate the copy from the week it ran in, and a first-time message is reported as untested rather than ranked. It reads the offers and cutoffs you have recorded, so a promotion that lives only in someone's calendar is invisible to it. It writes and updates the copy and does not change the bar's design or placement.
Install It
- Download the ZIP.
It is free and there is no account to create. - Unzip it into your agent's skills folder.
Claude Code reads ~/.claude/skills/, which is hidden by default: the command in the folder block opens it. Other agents scan their own directory, so drop the same folder there instead. - Ask your agent to use it.
Restart the agent if it was already running, then it picks the skill up with no config.
skills folder
Copy
~/.claude/skills/announcement-bar/
SKILL.md
references/message-library.md
bar/
# one file per day, with the expiry condition
# macOS: create the folder and open it in Finder
mkdir -p ~/.claude/skills && open ~/.claude/skills
# Windows: paste in the Explorer address bar
%USERPROFILE%\.claude\skills\Frequently asked questions
How is this different from writing banner copy myself?
The writing is the easy part. This decides which of the true things about today is worth the one sentence everyone sees, using what each message historically did to conversion, and it removes a message the day its reason expires. That second part is where banners actually fail.
Which agents does the skill run in?
Any agent that supports the open SKILL.md format: Claude Code, Cursor, Codex CLI, GitHub Copilot, Gemini CLI, Manus, Grok and others load it unmodified. The format is portable, the location is not. Each agent scans its own skills directory, so you drop the same folder into whichever one yours uses. There is no config file to edit and no API key to provision.
What does it need connected to work?
Active promotions and their end dates, shipping cutoffs, stock on hand, and site conversion by day so past messages can be scored. Without conversion history it still picks a message on the rules and says the lift figures are unavailable.
Why does it rank a shipping cutoff above a discount?
Because a cutoff is urgent and true for a specific reason, and urgency without a discount costs no margin. Discount messages tend to win on click-through and lose on contribution, which is visible once the bar is scored on conversion rather than on clicks.
Can it run more than one message?
It recommends one at a time and schedules the sequence, because a rotating bar is read as decoration and stops being noticed. The schedule tells you what runs today and what replaces it when today's reason expires.
What is included with the skill?
The skill itself, the message library reference, the daily update format, and the expiry rules. It is free and security scanned. We re-publish the ZIP when the library changes, so download it again if your recommendations start shifting.
The banner should say what today's numbers justify.
Polar reads live sales, stock and promo performance on one definition, so the copy you push each morning matches the state of the business.
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