> ## Documentation Index
> Fetch the complete documentation index at: https://docs.dualship.run/llms.txt
> Use this file to discover all available pages before exploring further.

# Quickstart

> Create your first API flow in minutes

This guide walks you through creating a simple API that fetches user data and returns a formatted response.

## Your First Flow

Create a flow that:

1. Accepts a `user_id` query parameter
2. Fetches user data from an external API
3. Returns a formatted response

```json theme={null}
{
  "name": "Get User",
  "trigger": {
    "type": "http",
    "config": {
      "method": "GET",
      "path": "/users"
    }
  },
  "nodes": [
    {
      "id": "fetch_user",
      "type": "http",
      "config": {
        "method": "GET",
        "url": "https://jsonplaceholder.typicode.com/users/{{request.query.user_id}}"
      }
    },
    {
      "id": "respond",
      "type": "response",
      "config": {
        "status": 200,
        "body": {
          "user": {
            "id": "{{fetch_user.output.body.id}}",
            "name": "{{fetch_user.output.body.name}}",
            "email": "{{fetch_user.output.body.email}}"
          }
        }
      }
    }
  ]
}
```

## Understanding the Structure

### Trigger

The trigger defines how the API is invoked:

```json theme={null}
"trigger": {
  "type": "http",
  "config": {
    "method": "GET",
    "path": "/users"
  }
}
```

This creates an endpoint at `GET /users`.

### Nodes

Nodes are the steps in your flow. Each node has:

* `id` - Unique identifier (used to reference outputs)
* `type` - The node type
* `config` - Type-specific configuration

### Template Expressions

Use `{{path}}` to reference data:

| Expression                      | Description                      |
| ------------------------------- | -------------------------------- |
| `{{request.query.user_id}}`     | Query parameter from the request |
| `{{request.body.email}}`        | Field from request body          |
| `{{fetch_user.output.body.id}}` | Output from a previous node      |

## Adding Validation

Add a `request` node to validate input:

```json theme={null}
{
  "name": "Get User (with validation)",
  "trigger": {
    "type": "http",
    "config": {
      "method": "GET",
      "path": "/users"
    }
  },
  "nodes": [
    {
      "id": "validate",
      "type": "request",
      "config": {
        "source": "request.query",
        "schema": {
          "user_id": "required|integer|min:1"
        }
      }
    },
    {
      "id": "fetch_user",
      "type": "http",
      "config": {
        "method": "GET",
        "url": "https://jsonplaceholder.typicode.com/users/{{request.query.user_id}}"
      }
    },
    {
      "id": "respond",
      "type": "response",
      "config": {
        "status": 200,
        "body": {
          "user": "{{fetch_user.output.body | pick:id:name:email}}"
        }
      }
    }
  ]
}
```

The `pick` pipe extracts only the specified fields from the response.

## Adding Conditional Logic

Handle cases where the user might not exist:

```json theme={null}
{
  "id": "check_exists",
  "type": "condition",
  "config": {
    "conditions": [
      {
        "if": "{{fetch_user.output.status_code}} == 200",
        "then": ["respond_success"]
      }
    ],
    "else": ["respond_not_found"]
  }
}
```

## Complete Example

Here's a full flow with validation, error handling, and conditional responses:

```json theme={null}
{
  "name": "Get User (Complete)",
  "trigger": {
    "type": "http",
    "config": {
      "method": "GET",
      "path": "/users"
    }
  },
  "nodes": [
    {
      "id": "validate",
      "type": "request",
      "config": {
        "source": "request.query",
        "schema": {
          "user_id": "required|integer|min:1|max:10"
        }
      }
    },
    {
      "id": "fetch_user",
      "type": "http",
      "config": {
        "method": "GET",
        "url": "https://jsonplaceholder.typicode.com/users/{{request.query.user_id}}",
        "on_error": "continue"
      }
    },
    {
      "id": "check_exists",
      "type": "condition",
      "config": {
        "conditions": [
          {
            "if": "{{fetch_user.output.success}} == true",
            "then": ["respond_success"]
          }
        ],
        "else": ["respond_not_found"]
      }
    },
    {
      "id": "respond_success",
      "type": "response",
      "config": {
        "status": 200,
        "body": {
          "success": true,
          "user": "{{fetch_user.output.body | pick:id:name:email:phone}}"
        }
      }
    },
    {
      "id": "respond_not_found",
      "type": "response",
      "config": {
        "status": 404,
        "body": {
          "success": false,
          "error": "User not found"
        }
      }
    }
  ]
}
```

## Next Steps

* [Flow Structure](/flow-structure) - Learn about triggers and execution flow
* [Nodes Overview](/nodes/overview) - Explore all 12 node types
* [Template Expressions](/reference/templates) - Master the template syntax