Distributed Slack apps

If you want your app to be Distributed, there's a little more work to be done than in the Single workspace scenario. A distributed app includes anyone being able to install the app from a install_url, and you keeping track of Slack tokens on behalf of the workspaces.

In Slackbot.NET, that means implementing a ITokenStore and exposing certain OAuth endpoints:

Program.cs

var builder = WebApplication.CreateBuilder(args);
 
builder.Services.AddAuthentication()
               .AddSlackbotEvents(c => c.
                   SigningSecret = Environment.GetEnvironmentVariable("SIGNING_SECRET")
               );
 
builder.Services.AddSlackbotDistribution(c => {
   c.CLIENT_ID = Environment.GetEnvironmentVariable("CLIENT_ID");
   c.CLIENT_SECRET = Environment.GetEnvironmentVariable("CLIENT_SECRET");
});
 
// Setup event handlers
builder.Services.AddSlackBotEvents<MyTokenStore>()
               .AddAppMentionHandler<DoStuff>()
 
 
var app = builder.Build();
app.Map("/authorize", a => a.UseSlackbotDistribution()); // OAuth callback endpoint
app.Map("/events", a => a.UseSlackbot()); // event endpoint
app.Run();
 
 
/// Bring-your-own-token-store:
class MyTokenStore : ITokenStore
{
   // _db is some persistance technology you choose (sql, mongo, whatever)
   public Task<Workspace Delete(string teamId) => _db.DeleteByTeamId(teamId);
   public Task Insert(Workspace slackTeam) => _db.Insert(slackTeam);
}

Install URL

A shareable link to install your slack app can be generated by filling in the blanks:

https://slack.com/oauth/v2/authorize?
   &user_scope=
   &scope={SCOPES}
   &client_id={CLIENT_ID}
   &redirect_uri={REDIRECT_URI}

Samples Azure Functions