Route human-in-the-loop approval requests with Slack and Postgres

by Mychel Garzon ✓ · 95 views · created 2026-06-27 · Document Extraction

What this workflow does

This workflow has 17 nodes and runs when an HTTP POST request hits its webhook URL. Along the way it connects Slack and Postgres.

How it runs

Trigger: When an HTTP POST request hits its webhook URL.

1. Verify Slack Request Signature (Code): runs custom JavaScript code
2. Determine Slack Request Type (Code): runs custom JavaScript code
3. Route by Request Type (If): checks a condition and branches into true / false
4. Create Slack Block Message (Code): runs custom JavaScript code
5. Handle Slack Callback Data (Code): runs custom JavaScript code
6. Send Message to Slack Channel (Slack): uses Slack
7. Acknowledge Slack Callback Fast (Respond to Webhook): sends the response back to the webhook caller
8. Check Slack Response Validity (Code): runs custom JavaScript code
9. Retrieve Context from Database (Postgres): select
10. Log Request in Database (Postgres): uses Postgres

…plus 6 more steps. See the full node list below.

Services it uses

SlackPostgres

Before you upgrade to n8n 3.0

Nodes used (6)

• Webhookn8n-nodes-base.webhook
• Coden8n-nodes-base.code
• Ifn8n-nodes-base.if
• Slackn8n-nodes-base.slack
• Postgresn8n-nodes-base.postgres
• Respond to Webhookn8n-nodes-base.respondToWebhook

From the author

Quick overview This workflow exposes a single webhook that either accepts new approval requests or handles Slack button callbacks, posting interactive Slack Block Kit messages and recording decisions in a PostgreSQL table. How it works 1. Receives a POST…

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