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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