What you will take away from this lesson
Sharing with a group of people who already talk in one place is easier as a post than as twenty shares. The team channel where store operations discusses the week is where the weekly report belongs.
A post from Plexara is not a pasted URL. It is a link share of its own, created for that channel, counted, listed on the item, and withdrawn with one click. This lesson covers making one, what the channel sees, and taking it back.
Learning Objectives
- 01Post an item to a Slack, Mattermost or email channel from the Share dialog.
- 02Choose who the posted link opens for, and explain why a file posts for signed-in people only.
- 03Read the preview before posting, and know what everyone in the channel will see.
- 04Withdraw a post without touching any other share.
Where this lesson sits
Lessons 801 and 802 added people one at a time. This lesson reaches a whole channel with one post.
800 Series: Working with People Outside the Company
- 801Who can open whatThe Share dialog by access: people and their roles, personas as groups whose membership is read when the item is opened, guests, and the one general link an item has.
- 802Requests for accessWhat a person without access sees, how the owner approves as viewer or editor or declines from the email, the Inbox or the dialog, and the limits and expiry an administrator sets.
- 803Posting to a channelPosting an item to a Slack, Mattermost or email channel as a link share of its own, what the channel sees, who the link opens for, and removing it.
- 804Portal permissionsThe persona editor by surface, one access level per portal area, the sharing permission, the access summary, and what deleting a persona checks first.
- 805Your clients as external peopleAn external persona per client organization, accounts that live in your identity provider, and the fixed limits: only what is shared, only shared threads, no sharing, no agent.
- 806Files from outsideUploads into an external person’s own folder, the External files folder staff open, and registering a client’s monthly file as a table beside the warehouse.
- 807Capstone: a supplier’s collection, thread and monthly fileAn ACME supplier collection shared with the supplier’s persona, a shared thread beside an internal one, and the supplier’s next price sheet registered and joined into the review.
The 800 series builds on sharing within the team from lesson 303 and registers a client’s file the way the 500 series does. Every example is on the ACME demo tenant, with a fictional supplier, Blue Harbor Wholesale.
Where a post can go
A post goes to one of the channels an administrator created. Four kinds exist, and each shows the post its own way.
Channels a post can go to
| Kind | Where it lands | What the channel shows |
|---|---|---|
| Slack | A channel the workspace bot is in | A preview image and the start of a text item, with the link |
| Mattermost | A channel the bot is in, on any of its teams | The same as Slack |
| Email list | The list the administrator named | A subject, the rendered body, files and a link button |
| Webhook | The system the administrator named | A title and body, with files and the link appended as links |
An administrator creates channels under Admin > Settings > Channels. A Slack or Mattermost channel can stand for its bot, and the person posting then picks among the chat channels the bot was invited to. A channel the bot joined a minute ago is offered the next time the list is read.

The channels you are offered
The dialog offers only the channels the person posting may use. On the demo tenant that is an email list for store operations and a webhook for systems.
The channels one person may post to on the demo tenant
What the agent calls. This is the exchange the agent has with Plexara on your behalf, shown for the technical reader. You ask in plain language; you never type any of it.
GET /api/v1/portal/channels
ops-events webhook immediate
carries: a title and a text body; files and the link
are appended as links
store-ops email immediate
carries: a subject, a rendered markdown body, files
and a link buttonThe list is per person. It holds only the channels on connections the person’s persona reaches, and a persona without the sharing permission gets no list at all. Each entry says what that channel carries, which is what the dialog’s preview is built from.
Making a post
Post to a channel sits in the footer of the Share dialog and takes four choices.
Share > Post to a channel
- 1
Choose the channel
One of the chat channels a bot is in, or another channel the person reaches.
- 2
Choose who the link opens for
Anyone who can sign in, which lasts until it is removed, or Anyone with the link, with when it stops working.
- 3
Add a message
Optional, posted with the link.
- 4
Read the preview
The dialog shows what the channel will see. For a channel that shows files, it says that everyone in the channel sees the preview image and, for a text item, the start of its content.
The preview matters more than the link setting. A channel of forty people all see the first lines of a document in their chat client, whether or not they ever open the link.

Who the posted link opens for
The choice of access is per post, so the same report can go to an internal channel for signed-in staff and, separately, as an expiring public link somewhere else.
Who a posted link opens for
| Choice | Offered for | How long |
|---|---|---|
| Anyone who can sign in | Assets, collections, files | Until removed; posting the same item to the same place again reuses it |
| Anyone with the link | Assets and collections | Until the expiry chosen |
| Only people with access | Files, agents and automations | The item’s own page; the post shares nothing |
A file has no public link of any kind, so a file posts for signed-in people or for the people who already have access. Posting for signed-in people shares the file with every signed-in person of an internal persona, as a viewer.
Taking a post back
Because each post is its own share, withdrawing one does not disturb the people and groups the item is shared with.
Taking a post back
Listed on the item
- Each post appears under Posted to channels in the Share view, naming the channel, with how often its link was opened.
Remove
- Stops that posted link from opening. The message stays in the channel’s history, and following it leads nowhere. Every other share on the item is unchanged.
A post that never went out
- When a post is held back by a repeat key or refused, the share it created is revoked with it, so nothing is left open by a message nobody received.
Posting from an agent or an automation
Posting, end to end
A post reaches a channel with a preview the poster has seen, opens for the people the poster chose, is counted on the item, and stops opening the moment it is removed.
Key terms
Three terms cover channel posts.
Key Terms
- Channel post
- A link share created for one channel and posted there, listed under Posted to channels and withdrawn with Remove.
- Preview
- What the channel shows before anyone opens the link: the preview image and, for text, the start of the content.
- Channel
- A named destination an administrator creates: a Slack or Mattermost channel, an email list, or a webhook.
