diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 92759da..e3f54a4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -24,5 +24,8 @@ jobs:
       - name: Run linter
         run: npm run lint
 
+      - name: Run unit tests
+        run: npm run test:unit
+
       - name: Build project
-        run: npm run build
\ No newline at end of file
+        run: npm run build
diff --git a/lib/utils/stellar-address.test.ts b/lib/utils/stellar-address.test.ts
new file mode 100644
index 0000000..31d2aec
--- /dev/null
+++ b/lib/utils/stellar-address.test.ts
@@ -0,0 +1,71 @@
+import { describe, it, expect } from "vitest";
+import * as StellarSdk from "@stellar/stellar-sdk";
+import { isValidStellarAddress, getStellarAddressError } from "./stellar-address";
+
+// A real valid Stellar public key (from a random keypair)
+const VALID_ADDRESS = StellarSdk.Keypair.random().publicKey();
+
+describe("isValidStellarAddress", () => {
+  it("accepts a real Stellar public key", () => {
+    expect(isValidStellarAddress(VALID_ADDRESS)).toBe(true);
+  });
+
+  it("rejects an address with wrong length", () => {
+    expect(isValidStellarAddress("GABC123")).toBe(false);
+  });
+
+  it("rejects an address that does not start with G", () => {
+    // Replace leading 'G' with 'A'
+    const bad = "A" + VALID_ADDRESS.slice(1);
+    expect(isValidStellarAddress(bad)).toBe(false);
+  });
+
+  it("rejects an address with a bad checksum", () => {
+    // Flip the last character
+    const last = VALID_ADDRESS[VALID_ADDRESS.length - 1];
+    const flipped = last === "A" ? "B" : "A";
+    expect(isValidStellarAddress(VALID_ADDRESS.slice(0, -1) + flipped)).toBe(false);
+  });
+
+  it("rejects empty string", () => {
+    expect(isValidStellarAddress("")).toBe(false);
+  });
+
+  it("rejects non-string values", () => {
+    expect(isValidStellarAddress(null)).toBe(false);
+    expect(isValidStellarAddress(undefined)).toBe(false);
+    expect(isValidStellarAddress(123)).toBe(false);
+    expect(isValidStellarAddress({})).toBe(false);
+  });
+
+  it("rejects whitespace-only string", () => {
+    expect(isValidStellarAddress("   ")).toBe(false);
+  });
+
+  it("rejects an address with invalid base32 characters", () => {
+    expect(isValidStellarAddress("G" + "0".repeat(55))).toBe(false);
+  });
+});
+
+describe("getStellarAddressError", () => {
+  it("returns null for a valid address", () => {
+    expect(getStellarAddressError(VALID_ADDRESS)).toBeNull();
+  });
+
+  it("returns required message for empty string", () => {
+    expect(getStellarAddressError("")).toBe("Stellar address is required");
+  });
+
+  it("returns required message for non-string", () => {
+    expect(getStellarAddressError(null)).toBe("Stellar address is required");
+    expect(getStellarAddressError(undefined)).toBe("Stellar address is required");
+  });
+
+  it("returns invalid message for a malformed address", () => {
+    expect(getStellarAddressError("GABC123")).toBe("Invalid Stellar address");
+  });
+
+  it("returns invalid message for wrong-length address starting with G", () => {
+    expect(getStellarAddressError("G" + "A".repeat(54))).toBe("Invalid Stellar address");
+  });
+});
diff --git a/lib/utils/stellar-address.ts b/lib/utils/stellar-address.ts
new file mode 100644
index 0000000..7bbc283
--- /dev/null
+++ b/lib/utils/stellar-address.ts
@@ -0,0 +1,31 @@
+/**
+ * Stellar address validation utility using the Stellar SDK.
+ *
+ * Uses StrKey.isValidEd25519PublicKey which decodes the Base32-encoded
+ * address and validates the checksum — far more robust than a simple
+ * length + prefix check.
+ */
+import { StrKey } from "@stellar/stellar-sdk";
+
+/**
+ * Returns true if `address` is a valid Stellar Ed25519 public key (G…).
+ */
+export function isValidStellarAddress(address: unknown): boolean {
+  if (typeof address !== "string" || address.trim() === "") return false;
+  try {
+    return StrKey.isValidEd25519PublicKey(address);
+  } catch {
+    return false;
+  }
+}
+
+/**
+ * Returns a descriptive error message when `address` is invalid,
+ * or null when it is valid.
+ */
+export function getStellarAddressError(address: unknown): string | null {
+  if (typeof address !== "string" || address.trim() === "") {
+    return "Stellar address is required";
+  }
+  return isValidStellarAddress(address) ? null : "Invalid Stellar address";
+}
diff --git a/package-lock.json b/package-lock.json
index 48ce039..40c72d4 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -4098,9 +4098,6 @@
         "arm"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -4115,9 +4112,6 @@
         "arm"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -4132,9 +4126,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -4149,9 +4140,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -4166,9 +4154,6 @@
         "loong64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -4183,9 +4168,6 @@
         "loong64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -4200,9 +4182,6 @@
         "ppc64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -4217,9 +4196,6 @@
         "ppc64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -4234,9 +4210,6 @@
         "riscv64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -4251,9 +4224,6 @@
         "riscv64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -4268,9 +4238,6 @@
         "s390x"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -4285,9 +4252,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -4302,9 +4266,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
diff --git a/package.json b/package.json
index 34ee712..09b29be 100644
--- a/package.json
+++ b/package.json
@@ -18,7 +18,6 @@
     "test:sensitive-actions": "node scripts/test-sensitive-actions-api.mjs",
     "test:vote-remove": "node scripts/test-vote-remove-api.mjs",
     "test:ephemeral": "node scripts/test-ephemeral-cleanup.mjs",
-    "test:unit": "vitest",
     "start": "next start",
     "cleanup:worker": "node scripts/ephemeral-cleanup-worker.js",
     "cleanup:trigger": "node scripts/trigger-cleanup.mjs"
diff --git a/vitest.config.ts b/vitest.config.ts
index 7df5736..8cfbec8 100644
--- a/vitest.config.ts
+++ b/vitest.config.ts
@@ -6,6 +6,7 @@ export default defineConfig({
     environment: "happy-dom",
     include: [
       "lib/blockchain/group-verification.test.ts",
+      "lib/utils/stellar-address.test.ts",
       "components/GroupVerificationBadge.test.tsx",
     ],
     globals: false,