Slack Laravel API

Easily handle Slack web hook requests via Laravel style routing with Middleware authentication. If you have ever implemented a webhook for Slack, you're going to want to try this.

Versions and compatibility

• PHP Version: >=8.0
• Laravel: ^7.0|^8.0

Installation

Composer

composer require stechstudio/slack-laravel-api

Configuration

.env

On each HTTP request that Slack sends, they add an X-Slack-Signature HTTP header. The signature is created by combining the signing secret with the body of the request we're sending using a standard HMAC-SHA256 keyed hash.

It is this signing secret that is used by the middleware to authenticate the request:

SLACK_SIGNING_SECRET="slacksecretestringhere"

Publish Slack Routes

artisan vendor:publish --provider=slack-routes

Usage

After publishing the Slack Routes you can look in base('routes/slack.php') to find the API route and some working examples of Slack routes.

Web Route

/*
|--------------------------------------------------------------------------
| Slack Webhook Routes
|--------------------------------------------------------------------------
|
| Here is where you can register Slack routes for your application. These
| routes are loaded by the RouteServiceProvider within a group which
| is assigned the "slack" middleware group. Enjoy building your API!
|
*/

Route::middleware('slack')->match(['get', 'post'], '/slack/api', 'STS\Slack\Http\Controllers\Slack@webhook');

By default, your application will have GET|POST|HEAD methods on the slack/api URI that will pass everything to STS\Slack\Http\Controllers\Slack@webhook via the slack middleware.

You may modify the URI or even add addition routes for other endpoints.

Slack Command Routes

use STS\Slack\Facades\SlackRoute;
use STS\Slack\SlashCommands\Echoes;

/*
|--------------------------------------------------------------------------
| Slack Command Routes
|--------------------------------------------------------------------------
|
| Here is where you can register Slack commands for your application.
|
*/
SlackRoute::handles('/hello', function (SlashCommand $slashCommand) {
    return 'Hello World';
});

SlackRoute::handles('/echo', Echoes::class);

These are working examples, and if you setup both Slack slash commands to use the configured URI, simply typing /hello or /echo yoodle will trigger the appropriate response.

The SlackRoute::handles() expects you to provide a command that matches the slash command in Slack, along with a Callable to handle the command.

This is best demonstrated in the Echo command sample.

<?php declare(strict_types=1);

namespace STS\Slack\SlashCommands;

use Illuminate\Support\Facades\Log;
use STS\Slack\Contracts\Messaging\Message as SlackMessage;
use STS\Slack\Contracts\SlashCommands\ControllerI;
use STS\Slack\Messaging\LayoutBlocks\Context;
use STS\Slack\Messaging\LayoutBlocks\Section;
use STS\Slack\Messaging\Message;
use STS\Slack\Models\SlashCommand;
use function json_encode;

class Echoes implements ControllerI
{

    public function handle(SlashCommand $slashCommand): SlackMessage
    {
        return $slashCommand->createMessage('*Echo:*  ' . $slashCommand->getText())
            ->addImage(
                'https://cdn.cp.adobe.io/content/2/dcx/9ed8e319-b714-4c8d-b9d5-7a6d419e50b3/rendition/preview.jpg/version/0/format/jpg/dimension/width/size/1200',
                'Echo Hacker'
            )
            ->addSection('*Slack Parameters* ', function(Section $section) use($slashCommand) {
                $section
                    ->addText("*Team ID*: {$slashCommand->getTeamId()}")
                    ->addText("*Team Domain*: {$slashCommand->getTeamDomain()}")
                    ->addText("*Channel ID*: {$slashCommand->getChannelId()}")
                    ->addText("*Channel Name*: {$slashCommand->getChannelName()}")
                    ->addText("*User ID*: {$slashCommand->getUserId()}")
                    ->addText("*User Name*: {$slashCommand->getUserName()}")
                    ->addText("*Command*: {$slashCommand->getCommand()}");
            })
            ->addSection("*Your Text*\n{$slashCommand->getText()}")
            ->addDivider()
            ->addContext(function(Context $context) {
                $context
                    ->addImage(
                        'https://avatars.slack-edge.com/2019-02-19/556373803382_e2c54afedc2a4fb73ccd_512.png',
                        'The Commander Logo'
                    )
                    ->addText('slack-laravel-api echo handler');
            })
            ->tap(function(Message $message) {
                Log::warning(json_encode($message->toSlackObjectArray()));
            });
    }
}

First note that your Command must implement STS\Slack\Contracts\SlashCommands\ControllerI in order to be valid. This ensures that we have a handle() that takes a SlashCommand and returns a SlackMessage.

As you can see, the SlashCommand provides access to everything that Slack sends you. The two most commonly used will be:

• $slashCommand->getCommand()
• $slashCommand->getText()

Assume the user typed /echo yoodle ay e who into Slack to trigger this. Then getCommand() would return /echo and getText() returns yoodle ay e who. We often then parse the text for sub-commands.

The SlackMessage class is a fairly powerful wrapper around the Building Block message layout format specified by the Slack API. Anything you can do with the blocks, you can do with this class.

Conclusion

That's it, handle your command and return a Slack-formatted message with Laravel middleware authenticating each Slack call for you and some handy classes to make handling these things easier.