Send Webhook to Slack, Free Automation in 5 Minutes

What you'll build

A workflow that receives any HTTP webhook, verifies its HMAC signature, formats a clean Slack message, and posts it to a channel. All on Requex's free tier.

Step 1, Create a Slack incoming webhook

1. Go to api.slack.com/apps, click Create New App → From scratch.
2. Name it (e.g. "Requex Webhook"), pick your workspace.
3. Sidebar → Incoming Webhooks → toggle Activate.
4. Click Add New Webhook to Workspace, pick a channel, copy the URL.

The URL looks like https://hooks.slack.com/services/T.../B.../...

Step 2, Generate a Requex webhook URL

Open requex.me. A unique webhook URL is created instantly, no signup needed for testing. Copy it.

Step 3, Build the workflow

In Requex, click Workflows. Add four nodes:

• Trigger, bound to your Requex webhook URL automatically.
• Webhook Verify, paste the signing secret from your source (Stripe, GitHub, Shopify). Algorithm: HMAC-SHA256. The node parses prefixes (sha256= for GitHub, t=…,v1=… for Stripe) automatically.
• Transform, write a small template that turns the payload into a Slack message body. Example:

  {
    "text": "💳 Stripe payment: $${body.amount / 100} from ${body.customer_email}"
  }

• Slack, paste your Slack incoming webhook URL.

Save the workflow. The trigger is now live.

Step 4, Point your source at Requex

In Stripe, GitHub, Shopify, or whatever source you use, add a webhook endpoint and paste your Requex URL. Pick the events you want forwarded.

Step 5, Trigger a test event

For Stripe: stripe trigger payment_intent.succeeded. For GitHub: push a commit. For Shopify: place a test order. The Slack message should land in seconds. The run trace in Requex shows every node execution, handy when a signature fails.

Common pitfalls

• •
  Signature mismatch. Many tools re-parse JSON before verifying, that breaks HMAC. Requex preserves the raw body through the Verify node, so signatures pass on the first try.
• •
  Slack rate limits. Add the Rate Limit node before Slack if your source bursts. 1 message per second is safe.
• •
  Wrong channel. Each Slack incoming webhook is bound to one channel. To post to multiple channels, add multiple Slack nodes.

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