Google Maps

The mapsutil/staticmap package generates Google Static Maps images.

Overview

Create map images with:

• Custom center, zoom, and dimensions
• Styled markers with colors and labels
• Preset regions (USA, Europe, World)
• Download as PNG files

Quick Start

import "github.com/grokify/gogoogle/mapsutil/staticmap"

// Create a map centered on San Francisco
mapConfig := staticmap.MapConfig{
    Center:  "San Francisco, CA",
    Zoom:    12,
    Width:   600,
    Height:  400,
    MapType: "roadmap",
    APIKey:  os.Getenv("GOOGLE_MAPS_API_KEY"),
}

url := staticmap.BuildURL(mapConfig)
fmt.Println(url)

MapConfig Options

Field	Type	Description
Center	string	Map center (address or lat,lng)
Zoom	int	Zoom level (1-21)
Width	int	Image width in pixels
Height	int	Image height in pixels
MapType	string	Map type
Markers	[]Marker	Map markers
APIKey	string	Google Maps API key

Map Types

Type	Description
roadmap	Standard road map
satellite	Satellite imagery
terrain	Terrain with roads
hybrid	Satellite with roads

Adding Markers

Basic Marker

mapConfig := staticmap.MapConfig{
    Center: "New York, NY",
    Zoom:   13,
    Width:  600,
    Height: 400,
    Markers: []staticmap.Marker{
        {
            Location: "Times Square, New York",
        },
    },
}

Styled Markers

markers := []staticmap.Marker{
    {
        Location: "40.758,-73.985",
        Color:    "red",
        Label:    "A",
    },
    {
        Location: "40.748,-73.986",
        Color:    "blue",
        Label:    "B",
    },
    {
        Location: "40.752,-73.977",
        Color:    "green",
        Label:    "C",
    },
}

Marker Options

Field	Type	Description
Location	string	Address or lat,lng
Color	string	Marker color
Label	string	Single character label
Size	string	Marker size

Colors

Standard colors: red, blue, green, yellow, purple, orange, gray, white, black

Custom hex: 0xFF5733

Sizes

• tiny - Smallest
• small - Small
• mid - Medium (default)

Preset Regions

// USA map
usaConfig := staticmap.USAMapConfig()
usaConfig.APIKey = apiKey
usaConfig.Markers = markers

// Europe map
europeConfig := staticmap.EuropeMapConfig()

// World map
worldConfig := staticmap.WorldMapConfig()

Download Map

// Get map image as bytes
imageData, err := staticmap.Download(mapConfig)
if err != nil {
    log.Fatal(err)
}

// Save to file
err = os.WriteFile("map.png", imageData, 0644)

URL Building

Generate URL without downloading:

url := staticmap.BuildURL(mapConfig)
fmt.Println(url)
// https://maps.googleapis.com/maps/api/staticmap?center=...

Multiple Markers Example

import "github.com/grokify/gogoogle/mapsutil/staticmap"

func createOfficeMap() error {
    offices := []staticmap.Marker{
        {Location: "San Francisco, CA", Color: "red", Label: "H"},    // HQ
        {Location: "New York, NY", Color: "blue", Label: "N"},
        {Location: "Austin, TX", Color: "blue", Label: "A"},
        {Location: "Seattle, WA", Color: "blue", Label: "S"},
    }

    mapConfig := staticmap.MapConfig{
        Center:   "United States",
        Zoom:     4,
        Width:    800,
        Height:   500,
        MapType:  "roadmap",
        Markers:  offices,
        APIKey:   os.Getenv("GOOGLE_MAPS_API_KEY"),
    }

    imageData, err := staticmap.Download(mapConfig)
    if err != nil {
        return err
    }

    return os.WriteFile("offices.png", imageData, 0644)
}

Zoom Levels

Zoom	Coverage
1	World
5	Continent
10	City
15	Streets
20	Buildings

API Key

Get a Google Maps API key:

1. Go to Google Cloud Console
2. Enable Maps Static API
3. Create credentials (API key)
4. Restrict key to Static Maps API

export GOOGLE_MAPS_API_KEY="your-api-key"

Limits

• Free tier: First $200/month free
• Image size: Max 640x640 (free) or 2048x2048 (premium)
• Markers: Max ~100 per request (URL length limit)

Best Practices

1. Secure API key - Restrict to specific APIs and IPs
2. Cache images - Don't regenerate static maps unnecessarily
3. Optimize size - Use appropriate dimensions for your use case
4. Handle errors - API may return errors for invalid locations

Next Steps

• Gmail - Email maps as attachments
• Sheets - Generate maps from location data