diff --git a/package-lock.json b/package-lock.json
index 7bd979d..e862d81 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -14,12 +14,12 @@
         "@stellar/stellar-sdk": "^12.1.0",
         "buffer": "^6.0.3",
         "expo": "~52.0.46",
-        "expo-asset": "^56.0.17",
+        "expo-asset": "~11.0.5",
         "expo-camera": "~16.0.0",
         "expo-clipboard": "~7.0.1",
         "expo-constants": "~17.0.8",
-        "expo-secure-store": "^56.0.4",
-        "expo-sharing": "^56.0.18",
+        "expo-secure-store": "~14.0.1",
+        "expo-sharing": "~13.0.1",
         "expo-status-bar": "~2.0.1",
         "react": "18.3.1",
         "react-native": "0.76.9",
@@ -2882,25 +2882,6 @@
         "node": ">= 10.0.0"
       }
     },
-    "node_modules/@expo/require-utils": {
-      "version": "56.1.6",
-      "resolved": "https://registry.npmjs.org/@expo/require-utils/-/require-utils-56.1.6.tgz",
-      "integrity": "sha512-e68r6X+c7yPxJP0gac/CaJc/RCHeLB2Bf4MyCuqfNM4YXfl1ONmQbQlRL0RbwBfEHn6A6UZKj+5UX9j0Im646g==",
-      "license": "MIT",
-      "dependencies": {
-        "@babel/code-frame": "^7.20.0",
-        "@babel/core": "^7.25.2",
-        "@babel/plugin-transform-modules-commonjs": "^7.24.8"
-      },
-      "peerDependencies": {
-        "typescript": "^5.0.0 || ^5.0.0-0 || ^6.0.0 || ^7.0.0"
-      },
-      "peerDependenciesMeta": {
-        "typescript": {
-          "optional": true
-        }
-      }
-    },
     "node_modules/@expo/rudder-sdk-node": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/@expo/rudder-sdk-node/-/rudder-sdk-node-1.1.1.tgz",
@@ -6880,13 +6861,15 @@
       }
     },
     "node_modules/expo-asset": {
-      "version": "56.0.21",
-      "resolved": "https://registry.npmjs.org/expo-asset/-/expo-asset-56.0.21.tgz",
-      "integrity": "sha512-0p5JByDPy6MxB1S2TBoz38r6I8IYx6z5uD/e00nc0sc9f8xRpcZPCJALbOsGW8PjOwXNfTyEE9KsC6xTLjC2ZA==",
+      "version": "11.0.5",
+      "resolved": "https://registry.npmjs.org/expo-asset/-/expo-asset-11.0.5.tgz",
+      "integrity": "sha512-TL60LmMBGVzs3NQcO8ylWqBumMh4sx0lmeJsn7+9C88fylGDhyyVnKZ1PyTXo9CVDBkndutZx2JUEQWM9BaiXw==",
       "license": "MIT",
       "dependencies": {
-        "@expo/image-utils": "^0.10.4",
-        "expo-constants": "~56.0.22"
+        "@expo/image-utils": "^0.6.5",
+        "expo-constants": "~17.0.8",
+        "invariant": "^2.2.4",
+        "md5-file": "^3.2.3"
       },
       "peerDependencies": {
         "expo": "*",
@@ -6894,69 +6877,6 @@
         "react-native": "*"
       }
     },
-    "node_modules/expo-asset/node_modules/@expo/env": {
-      "version": "2.3.1",
-      "resolved": "https://registry.npmjs.org/@expo/env/-/env-2.3.1.tgz",
-      "integrity": "sha512-JvBdZa5OkTd+dGEtt3fLW9OF6RlIp9SNu9VyMSiWPV5szMDTSAYbX8Uj3cRvZcU1zzaRbqnTSsHk2AE8WXHfxQ==",
-      "license": "MIT",
-      "dependencies": {
-        "chalk": "^4.0.0",
-        "debug": "^4.3.4",
-        "getenv": "^2.0.0"
-      },
-      "engines": {
-        "node": ">=20.12.0"
-      }
-    },
-    "node_modules/expo-asset/node_modules/@expo/image-utils": {
-      "version": "0.10.4",
-      "resolved": "https://registry.npmjs.org/@expo/image-utils/-/image-utils-0.10.4.tgz",
-      "integrity": "sha512-QGdC9eeNyF7vozMV77wQQwX4z3ZJK8D707WSTcBTE/XI19T41g5NtGVM/BMqb1oBV+zSZlNwpOA6bXbbvtC2UA==",
-      "license": "MIT",
-      "dependencies": {
-        "@expo/require-utils": "^56.1.6",
-        "@expo/spawn-async": "^1.8.0",
-        "chalk": "^4.0.0",
-        "getenv": "^2.0.0",
-        "jimp-compact": "0.16.1",
-        "parse-png": "^2.1.0",
-        "semver": "^7.6.0"
-      }
-    },
-    "node_modules/expo-asset/node_modules/expo-constants": {
-      "version": "56.0.22",
-      "resolved": "https://registry.npmjs.org/expo-constants/-/expo-constants-56.0.22.tgz",
-      "integrity": "sha512-XNRssTBSGDR3gsaYhhp513WdpPsLi89wgfYT0wLsCtMY8vXAgXR4jNlaYGXFCnvNVbx9gEDSBHOSntqRK1i8Lw==",
-      "license": "MIT",
-      "dependencies": {
-        "@expo/env": "~2.3.1"
-      },
-      "peerDependencies": {
-        "expo": "*",
-        "react-native": "*"
-      }
-    },
-    "node_modules/expo-asset/node_modules/getenv": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/getenv/-/getenv-2.0.0.tgz",
-      "integrity": "sha512-VilgtJj/ALgGY77fiLam5iD336eSWi96Q15JSAG1zi8NRBysm3LXKdGnHb4m5cuyxvOLQQKWpBZAT6ni4FI2iQ==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=6"
-      }
-    },
-    "node_modules/expo-asset/node_modules/semver": {
-      "version": "7.8.5",
-      "resolved": "https://registry.npmjs.org/semver/-/semver-7.8.5.tgz",
-      "integrity": "sha512-Y7/KDsb8LjooZpwaqGyulO6DQlksgCncchHGk+sZIY4SBvUocMBEFH5Ur1fI4dV+Jvl0w6cjvucaIi40puRioA==",
-      "license": "ISC",
-      "bin": {
-        "semver": "bin/semver.js"
-      },
-      "engines": {
-        "node": ">=10"
-      }
-    },
     "node_modules/expo-camera": {
       "version": "16.0.18",
       "resolved": "https://registry.npmjs.org/expo-camera/-/expo-camera-16.0.18.tgz",
@@ -7067,193 +6987,21 @@
       }
     },
     "node_modules/expo-secure-store": {
-      "version": "56.0.4",
-      "resolved": "https://registry.npmjs.org/expo-secure-store/-/expo-secure-store-56.0.4.tgz",
-      "integrity": "sha512-hjEi/gmpdFFJ9lYbdp3k3p/WchV7Gi0Qt8jt/m/0WJadqQrskafHAlDxbZkII1cN3Yd7zp9Lvkeq3UfGhSwirQ==",
+      "version": "14.0.1",
+      "resolved": "https://registry.npmjs.org/expo-secure-store/-/expo-secure-store-14.0.1.tgz",
+      "integrity": "sha512-QUS+j4+UG4jRQalgnpmTvvrFnMVLqPiUZRzYPnG3+JrZ5kwVW2w6YS3WWerPoR7C6g3y/a2htRxRSylsDs+TaQ==",
       "license": "MIT",
       "peerDependencies": {
         "expo": "*"
       }
     },
     "node_modules/expo-sharing": {
-      "version": "56.0.23",
-      "resolved": "https://registry.npmjs.org/expo-sharing/-/expo-sharing-56.0.23.tgz",
-      "integrity": "sha512-O/f6+ttCuwwTDnzM+ZqeVeNOJJ3lY1qvhoMfYeYAgEFi36qms5j+uuUISm520wmrG+1AwT7Is5tdSRk4zf+0AA==",
+      "version": "13.0.1",
+      "resolved": "https://registry.npmjs.org/expo-sharing/-/expo-sharing-13.0.1.tgz",
+      "integrity": "sha512-qych3Nw65wlFcnzE/gRrsdtvmdV0uF4U4qVMZBJYPG90vYyWh2QM9rp1gVu0KWOBc7N8CC2dSVYn4/BXqJy6Xw==",
       "license": "MIT",
-      "dependencies": {
-        "@expo/config-plugins": "^56.0.14",
-        "@expo/config-types": "^56.0.7",
-        "@expo/plist": "^0.7.0"
-      },
       "peerDependencies": {
-        "expo": "*",
-        "react": "*",
-        "react-native": "*"
-      }
-    },
-    "node_modules/expo-sharing/node_modules/@expo/config-plugins": {
-      "version": "56.0.14",
-      "resolved": "https://registry.npmjs.org/@expo/config-plugins/-/config-plugins-56.0.14.tgz",
-      "integrity": "sha512-pdjBwH67BF1dnim4N/OxgBshhil27eu3C9uuhwzzK2Bnzl6bIcdt9WjEVuMXluFnEpWe0ws5sxE8NvBR5Ms7bQ==",
-      "license": "MIT",
-      "dependencies": {
-        "@expo/config-types": "^56.0.7",
-        "@expo/json-file": "~10.2.0",
-        "@expo/plist": "^0.7.0",
-        "@expo/require-utils": "^56.1.6",
-        "@expo/sdk-runtime-versions": "^1.0.0",
-        "chalk": "^4.1.2",
-        "debug": "^4.3.5",
-        "getenv": "^2.0.0",
-        "glob": "^13.0.0",
-        "semver": "^7.5.4",
-        "slugify": "^1.6.6",
-        "xcode": "^3.0.1",
-        "xml2js": "0.6.0"
-      }
-    },
-    "node_modules/expo-sharing/node_modules/@expo/config-types": {
-      "version": "56.0.7",
-      "resolved": "https://registry.npmjs.org/@expo/config-types/-/config-types-56.0.7.tgz",
-      "integrity": "sha512-V7bxawNsNned/yMppAHdisIOxniZXgPKRWpIUiQOQBs45/A5MBd2gfDM4Ecq5gnbilnQUTaI6Zxn6JcW7L3TAA==",
-      "license": "MIT"
-    },
-    "node_modules/expo-sharing/node_modules/@expo/json-file": {
-      "version": "10.2.0",
-      "resolved": "https://registry.npmjs.org/@expo/json-file/-/json-file-10.2.0.tgz",
-      "integrity": "sha512-S6XzKe3R9GQeHiUPXc3xJjOv2VJhOEwFYf7xdC2z2cUqt3kZJ9mSO877sNQloVdnW/SUCtPY3bexlM7nwq+CAQ==",
-      "license": "MIT",
-      "dependencies": {
-        "@babel/code-frame": "^7.20.0",
-        "json5": "^2.2.3"
-      }
-    },
-    "node_modules/expo-sharing/node_modules/@expo/plist": {
-      "version": "0.7.0",
-      "resolved": "https://registry.npmjs.org/@expo/plist/-/plist-0.7.0.tgz",
-      "integrity": "sha512-vrpryU1GoqSIRNqRB2D3IjXDmzNYfiQpEF6AH/xknlD7eiYmEDt3mb26V7cLcedcPG8PY/1xWHdBXVQJfEAh6Q==",
-      "license": "MIT",
-      "dependencies": {
-        "@xmldom/xmldom": "^0.8.8",
-        "base64-js": "^1.5.1",
-        "xmlbuilder": "^15.1.1"
-      }
-    },
-    "node_modules/expo-sharing/node_modules/@xmldom/xmldom": {
-      "version": "0.8.13",
-      "resolved": "https://registry.npmjs.org/@xmldom/xmldom/-/xmldom-0.8.13.tgz",
-      "integrity": "sha512-KRYzxepc14G/CEpEGc3Yn+JKaAeT63smlDr+vjB8jRfgTBBI9wRj/nkQEO+ucV8p8I9bfKLWp37uHgFrbntPvw==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=10.0.0"
-      }
-    },
-    "node_modules/expo-sharing/node_modules/balanced-match": {
-      "version": "4.0.4",
-      "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-4.0.4.tgz",
-      "integrity": "sha512-BLrgEcRTwX2o6gGxGOCNyMvGSp35YofuYzw9h1IMTRmKqttAZZVU67bdb9Pr2vUHA8+j3i2tJfjO6C6+4myGTA==",
-      "license": "MIT",
-      "engines": {
-        "node": "18 || 20 || >=22"
-      }
-    },
-    "node_modules/expo-sharing/node_modules/brace-expansion": {
-      "version": "5.0.8",
-      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-5.0.8.tgz",
-      "integrity": "sha512-JZyDyq3D4AUifKTPOB7DELf6XsB3WdPuNxCtob1vFXPsSXhdAiHBWJ/tJ8HAc9aH84BK+5JFZLNkJKx3G9kzQg==",
-      "license": "MIT",
-      "dependencies": {
-        "balanced-match": "^4.0.2"
-      },
-      "engines": {
-        "node": "20 || >=22"
-      }
-    },
-    "node_modules/expo-sharing/node_modules/getenv": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/getenv/-/getenv-2.0.0.tgz",
-      "integrity": "sha512-VilgtJj/ALgGY77fiLam5iD336eSWi96Q15JSAG1zi8NRBysm3LXKdGnHb4m5cuyxvOLQQKWpBZAT6ni4FI2iQ==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=6"
-      }
-    },
-    "node_modules/expo-sharing/node_modules/glob": {
-      "version": "13.0.6",
-      "resolved": "https://registry.npmjs.org/glob/-/glob-13.0.6.tgz",
-      "integrity": "sha512-Wjlyrolmm8uDpm/ogGyXZXb1Z+Ca2B8NbJwqBVg0axK9GbBeoS7yGV6vjXnYdGm6X53iehEuxxbyiKp8QmN4Vw==",
-      "license": "BlueOak-1.0.0",
-      "dependencies": {
-        "minimatch": "^10.2.2",
-        "minipass": "^7.1.3",
-        "path-scurry": "^2.0.2"
-      },
-      "engines": {
-        "node": "18 || 20 || >=22"
-      },
-      "funding": {
-        "url": "https://github.com/sponsors/isaacs"
-      }
-    },
-    "node_modules/expo-sharing/node_modules/lru-cache": {
-      "version": "11.5.2",
-      "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-11.5.2.tgz",
-      "integrity": "sha512-4pfM1Ff0x50o0tQwb5ucw/RzNyD0/YJME6IVcStalZuMWxdt3sR3huStTtxz4PUmvZfRguvDejasvQ2kifR11g==",
-      "license": "BlueOak-1.0.0",
-      "engines": {
-        "node": "20 || >=22"
-      }
-    },
-    "node_modules/expo-sharing/node_modules/minimatch": {
-      "version": "10.2.6",
-      "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-10.2.6.tgz",
-      "integrity": "sha512-vpLQEs+VLCr1nU0BXS07maYoFwlDAH0gngQuuttxIwutDFEMHq2blX+8vpgxDdK3J1PwjCJiep77OitTZ4Ll1A==",
-      "license": "BlueOak-1.0.0",
-      "dependencies": {
-        "brace-expansion": "^5.0.8"
-      },
-      "engines": {
-        "node": "18 || 20 || >=22"
-      },
-      "funding": {
-        "url": "https://github.com/sponsors/isaacs"
-      }
-    },
-    "node_modules/expo-sharing/node_modules/path-scurry": {
-      "version": "2.0.2",
-      "resolved": "https://registry.npmjs.org/path-scurry/-/path-scurry-2.0.2.tgz",
-      "integrity": "sha512-3O/iVVsJAPsOnpwWIeD+d6z/7PmqApyQePUtCndjatj/9I5LylHvt5qluFaBT3I5h3r1ejfR056c+FCv+NnNXg==",
-      "license": "BlueOak-1.0.0",
-      "dependencies": {
-        "lru-cache": "^11.0.0",
-        "minipass": "^7.1.2"
-      },
-      "engines": {
-        "node": "18 || 20 || >=22"
-      },
-      "funding": {
-        "url": "https://github.com/sponsors/isaacs"
-      }
-    },
-    "node_modules/expo-sharing/node_modules/semver": {
-      "version": "7.8.5",
-      "resolved": "https://registry.npmjs.org/semver/-/semver-7.8.5.tgz",
-      "integrity": "sha512-Y7/KDsb8LjooZpwaqGyulO6DQlksgCncchHGk+sZIY4SBvUocMBEFH5Ur1fI4dV+Jvl0w6cjvucaIi40puRioA==",
-      "license": "ISC",
-      "bin": {
-        "semver": "bin/semver.js"
-      },
-      "engines": {
-        "node": ">=10"
-      }
-    },
-    "node_modules/expo-sharing/node_modules/xmlbuilder": {
-      "version": "15.1.1",
-      "resolved": "https://registry.npmjs.org/xmlbuilder/-/xmlbuilder-15.1.1.tgz",
-      "integrity": "sha512-yMqGBqtXyeN1e3TGYvgNgDVZ3j84W4cwkOXQswghol6APgZWaff9lnbvN7MHYJOiXsvGPXtjTYJEiC9J2wv9Eg==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=8.0"
+        "expo": "*"
       }
     },
     "node_modules/expo-status-bar": {
@@ -7266,23 +7014,6 @@
         "react-native": "*"
       }
     },
-    "node_modules/expo/node_modules/expo-asset": {
-      "version": "11.0.5",
-      "resolved": "https://registry.npmjs.org/expo-asset/-/expo-asset-11.0.5.tgz",
-      "integrity": "sha512-TL60LmMBGVzs3NQcO8ylWqBumMh4sx0lmeJsn7+9C88fylGDhyyVnKZ1PyTXo9CVDBkndutZx2JUEQWM9BaiXw==",
-      "license": "MIT",
-      "dependencies": {
-        "@expo/image-utils": "^0.6.5",
-        "expo-constants": "~17.0.8",
-        "invariant": "^2.2.4",
-        "md5-file": "^3.2.3"
-      },
-      "peerDependencies": {
-        "expo": "*",
-        "react": "*",
-        "react-native": "*"
-      }
-    },
     "node_modules/expo/node_modules/expo-file-system": {
       "version": "18.0.12",
       "resolved": "https://registry.npmjs.org/expo-file-system/-/expo-file-system-18.0.12.tgz",
@@ -14012,7 +13743,7 @@
       "version": "5.3.3",
       "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.3.3.tgz",
       "integrity": "sha512-pXWcraxM0uxAS+tN0AG/BF2TyqmHO014Z070UsJ+pFvYuRSq8KH8DmWpnbXe0pEPDHXZV3FcAbJkijJ5oNEnWw==",
-      "devOptional": true,
+      "dev": true,
       "license": "Apache-2.0",
       "bin": {
         "tsc": "bin/tsc",
diff --git a/package.json b/package.json
index e8729bc..2f0d08b 100644
--- a/package.json
+++ b/package.json
@@ -19,12 +19,12 @@
     "@stellar/stellar-sdk": "^12.1.0",
     "buffer": "^6.0.3",
     "expo": "~52.0.46",
-    "expo-asset": "^56.0.17",
+    "expo-asset": "~11.0.5",
     "expo-camera": "~16.0.0",
     "expo-clipboard": "~7.0.1",
     "expo-constants": "~17.0.8",
-    "expo-secure-store": "^56.0.4",
-    "expo-sharing": "^56.0.18",
+    "expo-secure-store": "~14.0.1",
+    "expo-sharing": "~13.0.1",
     "expo-status-bar": "~2.0.1",
     "react": "18.3.1",
     "react-native": "0.76.9",
@@ -42,5 +42,12 @@
     "react-test-renderer": "^18.3.1",
     "ts-jest": "^29.4.12",
     "typescript": "~5.3.3"
+  },
+  "expo": {
+    "doctor": {
+      "appConfigFieldsNotSyncedCheck": {
+        "enabled": false
+      }
+    }
   }
 }
diff --git a/src/api/apiSettings.test.ts b/src/api/apiSettings.test.ts
new file mode 100644
index 0000000..b200353
--- /dev/null
+++ b/src/api/apiSettings.test.ts
@@ -0,0 +1,43 @@
+import { validateApiBaseUrl } from "./apiSettings";
+
+describe("validateApiBaseUrl", () => {
+  it("accepts https URLs for normal API hosts", () => {
+    expect(validateApiBaseUrl("https://api.example.com").isValid).toBe(true);
+    expect(validateApiBaseUrl(" https://api.example.com/v1 ").isValid).toBe(true);
+  });
+
+  it("accepts localhost and loopback development URLs over http", () => {
+    expect(validateApiBaseUrl("http://localhost:4021").isValid).toBe(true);
+    expect(validateApiBaseUrl("http://dev.localhost:4021").isValid).toBe(true);
+    expect(validateApiBaseUrl("http://127.0.0.1:4021").isValid).toBe(true);
+    expect(validateApiBaseUrl("http://[::1]:4021").isValid).toBe(true);
+  });
+
+  it("accepts private LAN IP development URLs over http", () => {
+    expect(validateApiBaseUrl("http://10.0.2.2:4021").isValid).toBe(true);
+    expect(validateApiBaseUrl("http://172.16.0.2:4021").isValid).toBe(true);
+    expect(validateApiBaseUrl("http://172.31.255.255:4021").isValid).toBe(true);
+    expect(validateApiBaseUrl("http://192.168.1.20:4021").isValid).toBe(true);
+  });
+
+  it("rejects empty and incomplete URLs", () => {
+    expect(validateApiBaseUrl("").isValid).toBe(false);
+    expect(validateApiBaseUrl("api.example.com").isValid).toBe(false);
+  });
+
+  it("rejects unsupported protocols", () => {
+    expect(validateApiBaseUrl("ftp://api.example.com").isValid).toBe(false);
+  });
+
+  it("rejects insecure http for public hosts", () => {
+    expect(validateApiBaseUrl("http://api.example.com").isValid).toBe(false);
+    expect(validateApiBaseUrl("http://8.8.8.8:4021").isValid).toBe(false);
+    expect(validateApiBaseUrl("http://172.32.0.1:4021").isValid).toBe(false);
+  });
+
+  it("rejects credentials, query parameters, and fragments", () => {
+    expect(validateApiBaseUrl("https://user:pass@api.example.com").isValid).toBe(false);
+    expect(validateApiBaseUrl("https://api.example.com?debug=true").isValid).toBe(false);
+    expect(validateApiBaseUrl("https://api.example.com#resources").isValid).toBe(false);
+  });
+});
diff --git a/src/api/apiSettings.ts b/src/api/apiSettings.ts
index b9d65ac..663e739 100644
--- a/src/api/apiSettings.ts
+++ b/src/api/apiSettings.ts
@@ -5,10 +5,92 @@ const STORAGE_KEY = "mindvault_api_base_url";
 const DEFAULT_API_BASE_URL =
   (Constants.expoConfig?.extra?.apiUrl as string | undefined) ?? "http://localhost:4021";
 
+export interface ApiBaseUrlValidationResult {
+  isValid: boolean;
+  errorMessage?: string;
+}
+
 export function getDefaultApiBaseUrl(): string {
   return DEFAULT_API_BASE_URL;
 }
 
+function isLoopbackHost(hostname: string): boolean {
+  const normalized = hostname.toLowerCase();
+  return (
+    normalized === "localhost" ||
+    normalized.endsWith(".localhost") ||
+    normalized === "127.0.0.1" ||
+    normalized === "[::1]"
+  );
+}
+
+function isPrivateLanIp(hostname: string): boolean {
+  const parts = hostname.split(".").map((part) => Number(part));
+  if (
+    parts.length !== 4 ||
+    parts.some((part) => !Number.isInteger(part) || part < 0 || part > 255)
+  ) {
+    return false;
+  }
+
+  const [first, second] = parts;
+  return (
+    first === 10 ||
+    (first === 172 && second >= 16 && second <= 31) ||
+    (first === 192 && second === 168)
+  );
+}
+
+export function validateApiBaseUrl(value: string): ApiBaseUrlValidationResult {
+  const trimmed = value.trim();
+  if (!trimmed) {
+    return { isValid: false, errorMessage: "API base URL cannot be empty." };
+  }
+
+  let url: URL;
+  try {
+    url = new URL(trimmed);
+  } catch {
+    return {
+      isValid: false,
+      errorMessage: "Enter a complete URL, including http:// or https://.",
+    };
+  }
+
+  if (url.protocol !== "http:" && url.protocol !== "https:") {
+    return {
+      isValid: false,
+      errorMessage: "API base URL must use http:// or https://.",
+    };
+  }
+
+  if (url.username || url.password) {
+    return {
+      isValid: false,
+      errorMessage: "API base URL cannot include a username or password.",
+    };
+  }
+
+  if (url.search || url.hash) {
+    return {
+      isValid: false,
+      errorMessage: "API base URL cannot include query parameters or fragments.",
+    };
+  }
+
+  const allowsInsecureHttp =
+    isLoopbackHost(url.hostname) || isPrivateLanIp(url.hostname);
+  if (url.protocol === "http:" && !allowsInsecureHttp) {
+    return {
+      isValid: false,
+      errorMessage:
+        "Use https:// unless connecting to localhost or a private LAN IP.",
+    };
+  }
+
+  return { isValid: true };
+}
+
 export async function loadApiBaseUrl(): Promise<string> {
   const saved = await AsyncStorage.getItem(STORAGE_KEY);
   return saved && saved.trim().length > 0 ? saved : DEFAULT_API_BASE_URL;
@@ -21,5 +103,10 @@ export async function saveApiBaseUrl(value: string): Promise<void> {
     return;
   }
 
+  const validation = validateApiBaseUrl(trimmed);
+  if (!validation.isValid) {
+    throw new Error(validation.errorMessage ?? "Invalid API base URL.");
+  }
+
   await AsyncStorage.setItem(STORAGE_KEY, trimmed);
 }
diff --git a/src/screens/SettingsScreen.tsx b/src/screens/SettingsScreen.tsx
index e493ca2..aefff06 100644
--- a/src/screens/SettingsScreen.tsx
+++ b/src/screens/SettingsScreen.tsx
@@ -18,6 +18,7 @@ import {
   getDefaultApiBaseUrl,
   loadApiBaseUrl,
   saveApiBaseUrl,
+  validateApiBaseUrl,
 } from "../api/apiSettings";
 import { initializeApiBaseUrl } from "../api/resources";
 
@@ -42,10 +43,15 @@ export function SettingsScreen() {
 
   const handleSave = async () => {
     const trimmed = apiUrl.trim();
-    if (!trimmed) {
-      Alert.alert("Invalid URL", "API base URL cannot be empty.");
+    const validation = validateApiBaseUrl(trimmed);
+    if (!validation.isValid) {
+      Alert.alert(
+        "Invalid URL",
+        validation.errorMessage ?? "Invalid API base URL."
+      );
       return;
     }
+
     setIsSaving(true);
     try {
       await saveApiBaseUrl(trimmed);