Leppa User Guide

Leppa gives every Slack channel a lifespan. Spin one up, and it archives itself when its time is up — unless someone extends it. No more graveyard of dead channels, no more manual tidying.

This guide covers everything you can do with Leppa: the /leppa command, the channel lifecycle, templates, the admin dashboard, and answers to the questions that come up most.

Getting started

Add Leppa to your workspace

1. Go to app.leppa.io/install and click Add to Slack.
2. Approve the requested permissions. Depending on your workspace's settings, a Slack admin may need to approve the app.
3. That's it — the /leppa command is now available to everyone in the workspace.

Installing Leppa is a one-time, whole-workspace action. Individual members don't need to do anything to start using /leppa.

What Leppa can (and can't) see

Leppa is deliberately incurious. It knows about the channels it creates and their timers — nothing else:

• It never reads your messages (unless a workspace admin turns on the optional AI channel summaries — see below), and it never stores names, emails, or message content.
• It only manages channels it created (or was explicitly asked to manage). Channels you made yourself are invisible to it.
• Display names shown in the admin UI are fetched live from Slack and held in memory only.

The full details are in the Privacy & Data Policy.

The /leppa command

/leppa takes a verb that picks what you want to do. Type /leppa on its own (or /leppa help) to see them all:

summary also accepts the older spellings summarise and summarize.

Each verb is also registered as its own command — /leppa-new, /leppa-create, /leppa-summary, /leppa-settings, /leppa-templates — so they show up individually in Slack's autocomplete when you type /leppa. They do exactly the same thing as the spaced form; use whichever your fingers prefer.

Creating a channel

/leppa create follows one shape (and, for old muscle memory, you can drop the create and just type /leppa #name …):

/leppa create [template] [#channel-name] [duration] [@people or @usergroups] ["welcome message"]

If you'd rather click than remember the grammar, /leppa new opens a Slack dialog with the same fields (name, template, duration, invitees, welcome message). /leppa summary posts an on-demand AI summary of the current channel — see AI channel summaries.

Durations

A duration is a number followed by a unit:

The number must be greater than zero. If you leave the duration off, Leppa uses your workspace's default (7 days out of the box, or whatever an admin has set).

The channel prefix

So ephemeral channels stand out from ordinary ones in the sidebar, Leppa prepends a short prefix to every channel name — - out of the box, so /leppa #standup creates #-standup. Admins can change the prefix (or turn it off) workspace-wide in Settings, and each template can override it with its own. If an allowed-names policy is configured, it checks the name you asked for, before the prefix is added.

Examples

/leppa #release-foo

Creates #-release-foo (default prefix + your name) with the default 7-day timer.

/leppa #incident-42 48h @oncall

Creates #-incident-42, archives it in 48 hours, and invites the @oncall user group.

/leppa release #foo-launch @alice

Applies your release template (name pattern, welcome message, default invitees, duration) and also invites @alice. The typed #foo-launch still lands in the name: patterns that use {input} place it themselves; any other pattern gets it appended as a -foo-launch suffix. With a template you can also leave the name off entirely — /leppa release — and the pattern names the channel alone.

/leppa #warroom 3d "This channel self-destructs on Friday — decisions in the canvas please."

Creates #-warroom on a 3-day timer, and Leppa posts the quoted text as the channel's first message.

If something's wrong

Leppa replies to you privately (only you see it) and explains the problem — a name that's already taken, an unknown template, a duration of zero, or a name with characters Slack doesn't allow. Fix it and run the command again; nothing is created until the command succeeds.

The channel lifecycle

Every managed channel moves through a simple set of states. You'll see the same language in the reminder message and on the dashboard.

The intro message

Right after creating a channel, Leppa posts a short message in it explaining what it's doing: when the channel will archive and when the warning will come. For a channel created without a template it describes the workspace default settings and includes a Customise settings button — tapping it swaps the message for the same extend / keep / archive controls the pre-archive warning offers, so you can adjust the channel's lifetime the moment it's created. For templated channels the message names the template instead (any welcome message the template defines is posted right after).

The pre-archive warning

A configurable lead time before the deadline (24 hours by default), Leppa posts a message in the channel so no one is caught off guard. It offers four buttons:

• Extend 7 days — push the deadline out a week.
• Extend 30 days — push it out a month.
• Keep permanently — stop managing the channel; it will never auto-archive.
• Archive now — archive it immediately.

Anyone in the channel can tap a button. Once someone does, the message updates to show who acted and what happened, and the buttons disappear.

Extending re-arms the warning: an extended channel gets a fresh reminder before its new deadline — it will never archive without notice.

When a channel archives

Archiving in Slack hides the channel from the sidebar but keeps all its history — nothing is deleted, and anyone can unarchive it in Slack later. If you unarchive a channel Leppa was managing, Leppa notices and stops managing it (it won't re-arm the timer).

Templates

Templates capture the repeatable parts of channel creation so a single word on the command line sets everything up. They're managed by admins at app.leppa.io/templates.

A template can define:

• A key — the word you type: /leppa <key> #name.
• A name pattern — how the channel name is generated (see below).
• A channel prefix override — use the workspace prefix (the default), no prefix, or a custom one just for this template's channels.
• A default duration and warning lead — used when the command doesn't give its own.
• A topic, purpose, and welcome message — set on the channel right after it's created. The welcome message is posted by the Leppa bot.
• Default invitees — people and user groups invited every time.

Name-pattern placeholders

A name pattern is a channel name with placeholders that Leppa fills in:

For example, a pattern of release-{input}-{counter} invoked as /leppa release #foo produces #release-foo-1, then #release-foo-2 the next time, and so on. Whatever the placeholders resolve to is cleaned up to fit Slack's channel-name rules automatically.

A pattern that doesn't mention {input} still keeps the typed name: it's appended to the resolved pattern as a hyphen-separated suffix (standup-{date}

• /leppa standup #retro → #standup-2026-07-18-retro). Leave the #name off and the pattern stands alone; patterns that place {input} themselves do require a #name.

The admin dashboard

Workspace admins and owners can manage everything from app.leppa.io after signing in with Slack. (Non-admins can sign in, but the management screens are admin-only.)

Dashboard

The dashboard is the first thing you see at app.leppa.io — it lists every managed channel: its name, template, who created it, when, how long until it archives, and its current state. You can filter by state or template, narrow to a created-date window, and search by name. The state filter uses the same labels as the table above; its default, All active, shows everything still on a clock (Active, Archiving soon, and Extended together). For each active channel you can:

• Extend it by 7 or 30 days,
• Archive now, or
• Keep it permanently.

These are the same actions as the in-channel warning buttons, just from the web. Archive now and Keep give you a few seconds to change your mind: the row fades and an Undo button counts down before anything actually happens.

Analytics

Analytics shows how your workspace uses Leppa over the last 12 weeks: channels created per week, which templates get used, and four headline numbers. So the numbers aren't ambiguous:

• Created — channels created inside the 12-week window.
• Avg lifespan — average days from creation to archive, over channels archived in the window (whenever they were created).
• Extend rate — of warnings that got a response (extend, keep, or archive), the share answered by extending. Warnings still waiting for a response count toward neither side.
• Forgotten rate — the share of auto-archived channels that were never extended at any point. Channels a person archived deliberately don't count.

Export CSV downloads the same summary and breakdowns as a flat spreadsheet-friendly file, named for the window's start date.

Workspace settings

Under Settings you can set workspace-wide defaults:

• Default archive duration — used when a command gives no duration (e.g. 7d).
• Default warning lead — how far ahead the reminder posts (e.g. 24h). It must be shorter than the default duration.
• Channel name prefix — prepended to every /leppa channel name so ephemeral channels stand out (- by default; clear it for none).
• Allowed channel names (optional) — a regular expression every requested name must match, if you want to enforce a naming convention. It's checked against the requested name, before the prefix is added.
• Default template — applied when someone runs /leppa #name with no template key.

AI channel summaries (optional, off by default)

When a channel archives — on schedule or via the dashboard's Archive now — Leppa can post a short AI-generated summary of the conversation as its farewell message, and show it on the dashboard's "recently archived" list. You can also ask for one any time with /leppa summary in the channel (if the feature is off, Leppa replies with where an admin can enable it). It's off unless an admin turns it on, and enabling it is a deliberate, two-part consent:

• You click Enable in Settings and approve one extra Slack permission (channels:history) — the permission that lets Leppa read messages. Until you do this, Leppa cannot read any message.
• Summaries are generated by Cloudflare Workers AI (nothing leaves Cloudflare). The messages themselves are used only for that one request and never stored; the summary is produced from a pseudonymised transcript, so no names or handles are sent to the AI. When it's posted into the channel, the people who own a decision or follow-up are @-mentioned so they're notified; the copy kept for your dashboard stays pseudonymised.

Turn it off any time from Settings; Leppa stops reading messages immediately.

Uninstalling

From Settings you can uninstall Leppa. This revokes the bot token and stops all channel management immediately. Your data is kept for a 30-day grace period — reinstalling within it restores your templates and settings — and then it's purged. See the Privacy & Data Policy for the full retention schedule.

FAQ & troubleshooting

"That channel name is already taken." Slack already has a channel (active or archived) with that name. Pick a different name, or unarchive and reuse the existing one in Slack.

The channel was created but some people weren't invited. Leppa still creates the channel and tells you who it couldn't add — usually guests, external accounts, or deactivated users. Invite them manually if needed.

The reminder never appeared / the channel didn't archive. Leppa needs to be in the channel to post the reminder and to archive it. If the bot was removed from the channel, add it back. If a channel was deleted in Slack, Leppa can no longer manage it.

Can I get a channel back after it archives? Yes — archiving never deletes anything. Unarchive it in Slack and all its history is there. (Leppa will stop managing it once it's unarchived.)

Who can change templates and settings? Only workspace admins and owners. Everyone can use /leppa.

Does Leppa read our messages? No. Leppa stores channel IDs and timers, never message content, names, or emails. See the Privacy & Data Policy.

How do I delete our data? Uninstall Leppa — from Slack's app management page or from Leppa's Settings. Channel management stops immediately, and all stored data is purged after a 30-day grace period.