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diff --git a/fly-region/README.md b/fly-region/README.md
index 7c14f53..f6ec1e5 100644
--- a/fly-region/README.md
+++ b/fly-region/README.md
@@ -9,8 +9,56 @@ tags: [helper, parameter, fly]
 
 # Fly.io Region
 
-A parameter with all fly.io regions. This allows developers to select the region closest to them.
+This module adds Fly.io regions to your Coder template. Regions can be whitelisted using the `regions` argument and given custom names and custom icons with their respective map arguments (`custom_names`, `custom_icons`).
 
 ## Examples
 
-TODO
+### Using default settings
+
+We can use the simplest format here, only adding a default selection as the `atl` region.
+
+```hcl
+module "fly-region" {
+    source = "https://registry.coder.com/modules/fly-region"
+    default = "atl"
+}
+```
+
+![Fly.io Default](../.images/flyio-basic.png)
+
+### Using region whitelist
+
+The regions argument can be used to display only the desired regions in the Coder parameter.
+
+```hcl
+module "fly-region" {
+    source = "https://registry.coder.com/modules/fly-region"
+    default = "ams"
+    regions = ["ams", "arn", "atl"]
+}
+```
+
+![Fly.io Filtered Regions](../.images/flyio-filtered.png)
+
+### Using custom icons and names
+
+Set custom icons and names with their respective maps.
+
+```hcl
+module "fly-region" {
+    source = "https://registry.coder.com/modules/fly-region"
+    default = "ams"
+    custom_icons = {
+        "ams" = "/emojis/1f90e.png"
+    }
+    custom_names = {
+        "ams" = "We love the Netherlands!"
+    }
+}
+```
+
+![Fly.io custom icon and name](../.images/flyio-custom.png)
+
+## Associated template
+
+Also see the Coder template registry for a [Fly.io template](https://registry.coder.com/templates/fly-docker-image) that provisions workspaces as Fly.io machines.
diff --git a/fly-region/main.test.ts b/fly-region/main.test.ts
new file mode 100644
index 0000000..86f6bfc
--- /dev/null
+++ b/fly-region/main.test.ts
@@ -0,0 +1,25 @@
+import { describe, expect, it } from "bun:test";
+import {
+  executeScriptInContainer,
+  runTerraformApply,
+  runTerraformInit,
+  testRequiredVariables,
+} from "../test";
+
+describe("fly-region", async () => {
+  await runTerraformInit(import.meta.dir);
+
+  testRequiredVariables(import.meta.dir, {});
+
+  it("default output", async () => {
+    const state = await runTerraformApply(import.meta.dir, {});
+    expect(state.outputs.value.value).toBe("");
+  });
+
+  it("customized default", async () => {
+    const state = await runTerraformApply(import.meta.dir, {
+      default: "atl",
+    });
+    expect(state.outputs.value.value).toBe("atl");
+  });
+});
diff --git a/fly-region/main.tf b/fly-region/main.tf
new file mode 100644
index 0000000..ff6a9e3
--- /dev/null
+++ b/fly-region/main.tf
@@ -0,0 +1,287 @@
+terraform {
+  required_version = ">= 1.0"
+
+  required_providers {
+    coder = {
+      source  = "coder/coder"
+      version = ">= 0.12"
+    }
+  }
+}
+
+variable "display_name" {
+  default     = "Fly.io Region"
+  description = "The display name of the parameter."
+  type        = string
+}
+
+variable "description" {
+  default     = "The region to deploy workspace infrastructure."
+  description = "The description of the parameter."
+  type        = string
+}
+
+variable "default" {
+  default     = null
+  description = "The default region to use if no region is specified."
+  type        = string
+}
+
+variable "mutable" {
+  default     = false
+  description = "Whether the parameter can be changed after creation."
+  type        = bool
+}
+
+variable "custom_names" {
+  default     = {}
+  description = "A map of custom display names for region IDs."
+  type        = map(string)
+}
+
+variable "custom_icons" {
+  default     = {}
+  description = "A map of custom icons for region IDs."
+  type        = map(string)
+}
+
+variable "regions" {
+  default     = []
+  description = "List of regions to include for region selection."
+  type        = list(string)
+}
+
+locals {
+  regions = {
+    "ams" = {
+      name      = "Amsterdam, Netherlands"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1f3-1f1f1.png"
+    }
+    "arn" = {
+      name      = "Stockholm, Sweden"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1f8-1f1ea.png"
+    }
+    "atl" = {
+      name      = "Atlanta, Georgia (US)"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1fa-1f1f8.png"
+    }
+    "bog" = {
+      name      = "Bogotá, Colombia"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1e8-1f1f4.png"
+    }
+    "bom" = {
+      name      = "Mumbai, India"
+      gateway   = true
+      paid_only = true
+      icon      = "/emojis/1f1ee-1f1f3.png"
+    }
+    "bos" = {
+      name      = "Boston, Massachusetts (US)"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1fa-1f1f8.png"
+    }
+    "cdg" = {
+      name      = "Paris, France"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1eb-1f1f7.png"
+    }
+    "den" = {
+      name      = "Denver, Colorado (US)"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1fa-1f1f8.png"
+    }
+    "dfw" = {
+      name      = "Dallas, Texas (US)"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1fa-1f1f8.png"
+    }
+    "ewr" = {
+      name      = "Secaucus, NJ (US)"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1fa-1f1f8.png"
+    }
+    "eze" = {
+      name      = "Ezeiza, Argentina"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1e6-1f1f7.png"
+    }
+    "fra" = {
+      name      = "Frankfurt, Germany"
+      gateway   = true
+      paid_only = true
+      icon      = "/emojis/1f1e9-1f1ea.png"
+    }
+    "gdl" = {
+      name      = "Guadalajara, Mexico"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1f2-1f1fd.png"
+    }
+    "gig" = {
+      name      = "Rio de Janeiro, Brazil"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1e7-1f1f7.png"
+    }
+    "gru" = {
+      name      = "Sao Paulo, Brazil"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1e7-1f1f7.png"
+    }
+    "hkg" = {
+      name      = "Hong Kong, Hong Kong"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1ed-1f1f0.png"
+    }
+    "iad" = {
+      name      = "Ashburn, Virginia (US)"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1fa-1f1f8.png"
+    }
+    "jnb" = {
+      name      = "Johannesburg, South Africa"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1ff-1f1e6.png"
+    }
+    "lax" = {
+      name      = "Los Angeles, California (US)"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1fa-1f1f8.png"
+    }
+    "lhr" = {
+      name      = "London, United Kingdom"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1ec-1f1e7.png"
+    }
+    "mad" = {
+      name      = "Madrid, Spain"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1ea-1f1f8.png"
+    }
+    "mia" = {
+      name      = "Miami, Florida (US)"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1fa-1f1f8.png"
+    }
+    "nrt" = {
+      name      = "Tokyo, Japan"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1ef-1f1f5.png"
+    }
+    "ord" = {
+      name      = "Chicago, Illinois (US)"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1fa-1f1f8.png"
+    }
+    "otp" = {
+      name      = "Bucharest, Romania"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1f7-1f1f4.png"
+    }
+    "phx" = {
+      name      = "Phoenix, Arizona (US)"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1fa-1f1f8.png"
+    }
+    "qro" = {
+      name      = "Querétaro, Mexico"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1f2-1f1fd.png"
+    }
+    "scl" = {
+      name      = "Santiago, Chile"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1e8-1f1f1.png"
+    }
+    "sea" = {
+      name      = "Seattle, Washington (US)"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1fa-1f1f8.png"
+    }
+    "sin" = {
+      name      = "Singapore, Singapore"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1f8-1f1ec.png"
+    }
+    "sjc" = {
+      name      = "San Jose, California (US)"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1fa-1f1f8.png"
+    }
+    "syd" = {
+      name      = "Sydney, Australia"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1e6-1f1fa.png"
+    }
+    "waw" = {
+      name      = "Warsaw, Poland"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1f5-1f1f1.png"
+    }
+    "yul" = {
+      name      = "Montreal, Canada"
+      gateway   = false
+      paid_only = false
+      icon      = "/emojis/1f1e8-1f1e6.png"
+    }
+    "yyz" = {
+      name      = "Toronto, Canada"
+      gateway   = true
+      paid_only = false
+      icon      = "/emojis/1f1e8-1f1e6.png"
+    }
+  }
+}
+
+data "coder_parameter" "fly_region" {
+  name         = "flyio_region"
+  display_name = var.display_name
+  description  = var.description
+  default      = (var.default != null && var.default != "") && ((var.default != null ? contains(var.regions, var.default) : false) || length(var.regions) == 0) ? var.default : null
+  mutable      = var.mutable
+  dynamic "option" {
+    for_each = { for k, v in local.regions : k => v if anytrue([for d in var.regions : k == d]) || length(var.regions) == 0 }
+    content {
+      name  = try(var.custom_names[option.key], option.value.name)
+      icon  = try(var.custom_icons[option.key], option.value.icon)
+      value = option.key
+    }
+  }
+}
+
+output "value" {
+  value = data.coder_parameter.fly_region.value
+}
\ No newline at end of file