Lindy Hello World

Overview

Build a minimal Lindy AI agent: Webhook Received trigger -> LLM processing -> Slack notification. Demonstrates the three core building blocks every Lindy agent uses: Trigger, Agent Step (prompt + model + skills), and Action.

Prerequisites

• Lindy account at https://app.lindy.ai
• Slack workspace connected (or Gmail for email variant)
• Completed

  lindy-install-auth

  setup

Instructions

Step 1: Create Agent via Dashboard

1. Click "New Agent" at https://app.lindy.ai
2. In the prompt field ("How can I help you?"), type:

   When I send a webhook, summarize the message and post it to Slack
   

3. Agent Builder auto-generates the workflow with trigger + action nodes

Step 2: Configure the Webhook Trigger

1. Click the trigger node at the top of the workflow canvas
2. Select Webhook Received
3. Copy the generated URL:

   https://public.lindy.ai/api/v1/webhooks/<unique-id>
   

4. Click Generate Secret — copy immediately (shown once)

Step 3: Add the Slack Action

1. Click "+" to add a step
2. Search for Slack Send Channel Message
3. Authorize your Slack workspace when prompted
4. Configure fields:
   • Channel:

     #general

     (or test channel)
   • Message field mode: AI Prompt
   • Instruction:

     Summarize the webhook payload in one sentence.
     Payload: {{webhook_received.request.body}}
     

Step 4: Set the Agent Prompt

Open Settings > Prompt:

You are a webhook summarizer. When you receive a webhook payload,
extract the key information and create a concise one-sentence summary.
Be factual and specific. Do not add opinions or speculation.

Step 5: Test It

curl -X POST "https://public.lindy.ai/api/v1/webhooks/YOUR_ID" \
  -H "Authorization: Bearer YOUR_SECRET" \
  -H "Content-Type: application/json" \
  -d '{
    "event": "order.created",
    "customer": "Jane Doe",
    "amount": 149.99,
    "items": ["Widget Pro", "Adapter Cable"]
  }'

Expected Slack message:

Jane Doe placed a $149.99 order for Widget Pro and Adapter Cable.

Step 6: Verify in Dashboard

Navigate to the Tasks tab in your agent view. Confirm status shows Completed. Click into the task to see each step's input/output for debugging.

Agent Anatomy

Webhook Data Variables

{{webhook_received.request.body}}

{{webhook_received.request.headers}}

{{webhook_received.request.query}}

Field Configuration Modes

Variant: Email Instead of Slack

Replace the Slack action with Gmail Send Email:

• To: Set manually or reference a webhook field
• Subject: AI Prompt —

  "Summary: {{webhook_received.request.body.event}}"

• Body: AI Prompt —

  "Summarize this event: {{webhook_received.request.body}}"

Error Handling

Bearer <secret>

{{webhook_received.request.body}}

Cost

~1-3 credits per invocation on basic models. Free tier (400 credits/month) supports ~130-400 test runs per month.

Resources

• Getting Started 101
• Webhook Triggers Academy
• Lindy Documentation

Next Steps

Proceed to

lindy-core-workflow-a