Slack

Members sign in with their Slack account, in the system browser.

Before you start


Console	Slack API apps
Endpoint group	Social Login
Email	Returned, but not verified — cannot match an existing account
Signs in	In the browser

Create the app

Open api.slack.com/apps and create an app from scratch, choosing a workspace to develop it in.
Open OAuth & Permissions.
Add the redirect address under Redirect URLs: the string from Memberside → API Keys → Social Login → Slack, which looks like https://yoursite.com/wp-json/memberside/v1/social/callback/slack. Press Save URLs.
Scroll to Scopes and find User Token Scopes — not Bot Token Scopes.
Add openid, profile and email there.
Copy the Client ID and Client Secret from Basic Information → App Credentials.

Distributing the app

An app developed in one workspace signs in members of that workspace. To let members of any workspace sign in, turn on Public Distribution under Manage Distribution, which requires the redirect URL to be HTTPS and the app to have no hard-coded workspace tokens.

Why the email cannot match an existing account

Slack returns an address without asserting it has been verified, so Memberside will not attach a Slack sign-in to an account that already exists by matching it. Existing members should sign in first and link Slack from Social Connects.

What to paste into Memberside

Under Memberside → API Keys → Social Login → Slack:

Field	Value
Client ID	The Client ID
Client secret	The Client Secret

When it does not work

Symptom	Cause	Fix
Authorisation succeeds, nothing comes back	The scopes are on the bot token	Move them to User Token Scopes
“redirect_uri did not match”	The URL was added but not saved	Press Save URLs
Only your own workspace can sign in	The app is not distributed	Turn on Public Distribution
A second account is created for an existing member	Slack’s email is unverified, so matching is refused	Have them sign in first, then link