From 098fba11feb48ffe6241832c0496b2f98a5c9a13 Mon Sep 17 00:00:00 2001
From: WolfieLeader <koren2318@gmail.com>
Date: Thu, 19 Mar 2026 03:55:21 +0200
Subject: [PATCH 1/4] feat(type): add string.base58 built-in validator (#1520)

---
 ark/type/__tests__/keywords/string.test.ts | 14 ++++++++++++++
 ark/type/keywords/string.ts                |  4 ++++
 2 files changed, 18 insertions(+)

diff --git a/ark/type/__tests__/keywords/string.test.ts b/ark/type/__tests__/keywords/string.test.ts
index 06fd5ae464..7a02b7e02e 100644
--- a/ark/type/__tests__/keywords/string.test.ts
+++ b/ark/type/__tests__/keywords/string.test.ts
@@ -34,6 +34,20 @@ contextualize(() => {
 		)
 	})
 
+	it("base58", () => {
+		const Base58 = type("string.base58")
+		attest(Base58("5HueCGU8rMjxEXxiPuD5BDku4MkFqeZyd4dZ1jvhTVqvbTLvyTJ")).snap(
+			"5HueCGU8rMjxEXxiPuD5BDku4MkFqeZyd4dZ1jvhTVqvbTLvyTJ"
+		)
+		attest(Base58("abc123")).snap("abc123")
+		attest(Base58("invalid0OIl").toString()).snap(
+			'must be base58-encoded (was "invalid0OIl")'
+		)
+		attest(Base58("").toString()).snap(
+			'must be base58-encoded (was "")'
+		)
+	})
+
 	it("base64", () => {
 		const B64 = type("string.base64")
 		attest(B64("fn5+")).snap("fn5+")
diff --git a/ark/type/keywords/string.ts b/ark/type/keywords/string.ts
index 05064933b5..ab00af8d91 100644
--- a/ark/type/keywords/string.ts
+++ b/ark/type/keywords/string.ts
@@ -80,6 +80,8 @@ export declare namespace stringInteger {
 
 const hex = regexStringNode(/^[\dA-Fa-f]+$/, "hex characters only")
 
+const base58 = regexStringNode(/^[1-9A-HJ-NP-Za-km-z]+$/, "base58-encoded")
+
 const base64 = Scope.module(
 	{
 		root: regexStringNode(
@@ -911,6 +913,7 @@ export const string = Scope.module(
 			"only letters and digits 0-9"
 		),
 		hex,
+		base58,
 		base64,
 		capitalize,
 		creditCard,
@@ -945,6 +948,7 @@ export declare namespace string {
 		alpha: string
 		alphanumeric: string
 		hex: string
+		base58: string
 		base64: base64.submodule
 		capitalize: capitalize.submodule
 		creditCard: string

From 48aa7e40b290f912a119a4726a6b99e3f60a43fe Mon Sep 17 00:00:00 2001
From: WolfieLeader <koren2318@gmail.com>
Date: Thu, 19 Mar 2026 04:05:56 +0200
Subject: [PATCH 2/4] style: fix prettier formatting in string test

---
 ark/type/__tests__/keywords/string.test.ts | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/ark/type/__tests__/keywords/string.test.ts b/ark/type/__tests__/keywords/string.test.ts
index 7a02b7e02e..1b47c6cd0d 100644
--- a/ark/type/__tests__/keywords/string.test.ts
+++ b/ark/type/__tests__/keywords/string.test.ts
@@ -43,9 +43,7 @@ contextualize(() => {
 		attest(Base58("invalid0OIl").toString()).snap(
 			'must be base58-encoded (was "invalid0OIl")'
 		)
-		attest(Base58("").toString()).snap(
-			'must be base58-encoded (was "")'
-		)
+		attest(Base58("").toString()).snap('must be base58-encoded (was "")')
 	})
 
 	it("base64", () => {

From 85c1a4cca6a15ee80e3683e73d7e057d6f35deaa Mon Sep 17 00:00:00 2001
From: WolfieLeader <koren2318@gmail.com>
Date: Thu, 19 Mar 2026 04:12:33 +0200
Subject: [PATCH 3/4] test: individually verify each excluded base58 character

---
 ark/type/__tests__/keywords/string.test.ts | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/ark/type/__tests__/keywords/string.test.ts b/ark/type/__tests__/keywords/string.test.ts
index 1b47c6cd0d..cf7b21bb72 100644
--- a/ark/type/__tests__/keywords/string.test.ts
+++ b/ark/type/__tests__/keywords/string.test.ts
@@ -40,9 +40,10 @@ contextualize(() => {
 			"5HueCGU8rMjxEXxiPuD5BDku4MkFqeZyd4dZ1jvhTVqvbTLvyTJ"
 		)
 		attest(Base58("abc123")).snap("abc123")
-		attest(Base58("invalid0OIl").toString()).snap(
-			'must be base58-encoded (was "invalid0OIl")'
-		)
+		attest(Base58("0").toString()).snap('must be base58-encoded (was "0")')
+		attest(Base58("O").toString()).snap('must be base58-encoded (was "O")')
+		attest(Base58("I").toString()).snap('must be base58-encoded (was "I")')
+		attest(Base58("l").toString()).snap('must be base58-encoded (was "l")')
 		attest(Base58("").toString()).snap('must be base58-encoded (was "")')
 	})
 

From cc6a84d7f1c6a66e1cb281bef57b15628e196f98 Mon Sep 17 00:00:00 2001
From: WolfieLeader <koren2318@gmail.com>
Date: Thu, 19 Mar 2026 05:03:23 +0200
Subject: [PATCH 4/4] test: register string.base58 in allConfig integration
 test

---
 ark/type/__tests__/integration/allConfig.ts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/ark/type/__tests__/integration/allConfig.ts b/ark/type/__tests__/integration/allConfig.ts
index 2208e49f04..b9ba6e89d7 100644
--- a/ark/type/__tests__/integration/allConfig.ts
+++ b/ark/type/__tests__/integration/allConfig.ts
@@ -107,6 +107,9 @@ configure({
 		"string.hex": {
 			description: "configured"
 		},
+		"string.base58": {
+			description: "configured"
+		},
 		"string.base64.url": {
 			description: "configured"
 		},