diff --git a/src/aws.d.ts b/src/aws.d.ts
new file mode 100644
index 0000000..d0fd08d
--- /dev/null
+++ b/src/aws.d.ts
@@ -0,0 +1,16 @@
+type AccountId = `${number}`;
+type Region = `${string}-${string}-${number}`;
+
+type Arn<
+  S extends string,
+  R extends Region | "",
+  T extends string
+> = `arn:aws:${S}:${R}:${AccountId}:${T}`;
+
+type RegionalArn<S extends string, T extends string> = Arn<S, Region, T>;
+type GlobalArn<S extends string, T extends string> = Arn<S, "", T>;
+
+type RuleArn = RegionalArn<"events", `rule/${string}/${string}`>;
+type RoleArn = GlobalArn<"iam", `role/${string}`>;
+type SqsArn = RegionalArn<"sqs", string>;
+type LambdaArn = RegionalArn<"lambda", `function:${string}`>;
diff --git a/src/brand.d.ts b/src/brand.d.ts
new file mode 100644
index 0000000..d46d3d9
--- /dev/null
+++ b/src/brand.d.ts
@@ -0,0 +1 @@
+type Brand<T, B> = T & { readonly __brand: B };
\ No newline at end of file
diff --git a/src/uuid.d.ts b/src/uuid.d.ts
new file mode 100644
index 0000000..f9c8ac4
--- /dev/null
+++ b/src/uuid.d.ts
@@ -0,0 +1,6 @@
+type VariantNibble = "8" | "9" | "A" | "B";
+
+type UUID<V extends '4'|'7'> = `${string}-${string}-${V}${string}-${VariantNibble}${string}-${string}`
+
+type UUIDv4 = UUID<'4'>;
+type UUIDv7 = UUID<'7'>;