lindy-hello-world

What this skill does

# 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
- 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
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

```bash
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

| Component | Purpose | Hello World Value |
|-----------|---------|-------------------|
| **Prompt** | Core behavioral instructions | "Summarize webhook payloads" |
| **Model** | AI engine powering decisions | Default (GPT-4 / Claude / Gemini) |
| **Skills** | Available actions & tools | Slack Send Channel Message |
| **Exit Conditions** | When the task is "done" | Message sent successfully |

## Webhook Data Variables

| Variable | Contents |
|----------|----------|
| `{{webhook_received.request.body}}` | Full JSON payload |
| `{{webhook_received.request.headers}}` | HTTP request headers |
| `{{webhook_received.request.query}}` | URL query parameters |

## Field Configuration Modes

| Mode | Behavior | Credit Cost |
|------|----------|-------------|
| **Auto** | Agent determines value from context | Standard |
| **AI Prompt** | Natural language instructions generate content | Standard |
| **Set Manually** | Exact value, no AI processing | Lower |

## 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

| Issue | Cause | Solution |
|-------|-------|----------|
| Webhook returns 401 | Missing Authorization header | Add `Bearer <secret>` header |
| Slack message not sent | Channel not authorized | Re-authorize Slack in Lindy |
| Task shows "Failed" | Action misconfigured | Check field references in step config |
| No task created | Agent not active | Publish/activate the agent |
| Empty summary | Payload not reaching LLM | Verify `{{webhook_received.request.body}}` reference |

## 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](https://www.lindy.ai/academy-lessons/getting-started-101)
- [Webhook Triggers Academy](https://www.lindy.ai/academy-lessons/webhook-triggers)
- [Lindy Documentation](https://docs.lindy.ai)

## Next Steps

Proceed to `lindy-core-workflow-a` for a full multi-step agent workflow.