diff --git a/README.md b/README.md
index 434faf2..70dc57d 100644
--- a/README.md
+++ b/README.md
@@ -21,3 +21,22 @@ scripts/verify_prd_site_rendering.sh
 scripts/verify_windows_app_manifest.sh
 cargo run -p ely_app
 ```
+
+## Cloudflare Auth Configuration
+
+`/api/auth/*` is served by Better Auth in the Cloudflare Worker. Local `wrangler dev`
+uses `ELY_AUTH_BASE_URL` from `cloudflare/wrangler.toml`; deployed environments should
+set the matching public Worker origin.
+
+Use Wrangler secrets or an untracked `cloudflare/.dev.vars` file for the remaining auth
+bindings:
+
+```bash
+wrangler secret put ELY_AUTH_SECRET
+wrangler secret put ELY_AUTH_GOOGLE_CLIENT_ID
+wrangler secret put ELY_AUTH_GOOGLE_CLIENT_SECRET
+wrangler secret put ELY_AUTH_GITHUB_CLIENT_ID
+wrangler secret put ELY_AUTH_GITHUB_CLIENT_SECRET
+wrangler secret put ELY_AUTH_EMAIL_OTP_ENDPOINT
+wrangler secret put ELY_AUTH_EMAIL_OTP_TOKEN
+```
diff --git a/cloudflare/package-lock.json b/cloudflare/package-lock.json
index 744012b..29d593c 100644
--- a/cloudflare/package-lock.json
+++ b/cloudflare/package-lock.json
@@ -7,6 +7,9 @@
     "": {
       "name": "@elydora/cloudflare-worker",
       "version": "0.1.0",
+      "dependencies": {
+        "better-auth": "^1.6.9"
+      },
       "devDependencies": {
         "@cloudflare/workers-types": "4.20260508.1",
         "@types/node": "24.12.3",
@@ -14,6 +17,138 @@
         "wrangler": "4.90.0"
       }
     },
+    "node_modules/@better-auth/core": {
+      "version": "1.6.9",
+      "resolved": "https://registry.npmjs.org/@better-auth/core/-/core-1.6.9.tgz",
+      "integrity": "sha512-ADFk5pwmLybmc+LvYvXJ6M1x2oY/EyYLkwLuH0x28FUq12DfjL0wnE7g+WRDf3yozDO+qIxTpFGXDGwLKbfz0w==",
+      "license": "MIT",
+      "dependencies": {
+        "@opentelemetry/semantic-conventions": "^1.39.0",
+        "@standard-schema/spec": "^1.1.0",
+        "zod": "^4.3.6"
+      },
+      "peerDependencies": {
+        "@better-auth/utils": "0.4.0",
+        "@better-fetch/fetch": "1.1.21",
+        "@cloudflare/workers-types": ">=4",
+        "@opentelemetry/api": "^1.9.0",
+        "better-call": "1.3.5",
+        "jose": "^6.1.0",
+        "kysely": "^0.28.5",
+        "nanostores": "^1.0.1"
+      },
+      "peerDependenciesMeta": {
+        "@cloudflare/workers-types": {
+          "optional": true
+        },
+        "@opentelemetry/api": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@better-auth/drizzle-adapter": {
+      "version": "1.6.9",
+      "resolved": "https://registry.npmjs.org/@better-auth/drizzle-adapter/-/drizzle-adapter-1.6.9.tgz",
+      "integrity": "sha512-Lcco5hOGrMgc4XKAkvB6x72eQm4wCcya8IevMg4wBHY9W9GVg8pu23rpRX6VsVQSO4Ux13S7lFwUWtF7/r9aKw==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@better-auth/core": "^1.6.9",
+        "@better-auth/utils": "0.4.0",
+        "drizzle-orm": "^0.45.2"
+      },
+      "peerDependenciesMeta": {
+        "drizzle-orm": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@better-auth/kysely-adapter": {
+      "version": "1.6.9",
+      "resolved": "https://registry.npmjs.org/@better-auth/kysely-adapter/-/kysely-adapter-1.6.9.tgz",
+      "integrity": "sha512-gyjuuxJtZ4o9G9z9q4kqn24X2kvMSp7F+KHogYxF03SnXY/2WleAcuj57iC4wP3e9mGDbjPOrnM5K6Kr3Ktdpw==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@better-auth/core": "^1.6.9",
+        "@better-auth/utils": "0.4.0",
+        "kysely": "^0.28.14"
+      },
+      "peerDependenciesMeta": {
+        "kysely": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@better-auth/memory-adapter": {
+      "version": "1.6.9",
+      "resolved": "https://registry.npmjs.org/@better-auth/memory-adapter/-/memory-adapter-1.6.9.tgz",
+      "integrity": "sha512-XmIG4tUnOXZ+KEcWjHUjOI9Z5donD09dC2t/AQTXifAUIqx7cySg86w0KTM09ArzAxRx1fCqO36Wkt5nULnrkQ==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@better-auth/core": "^1.6.9",
+        "@better-auth/utils": "0.4.0"
+      }
+    },
+    "node_modules/@better-auth/mongo-adapter": {
+      "version": "1.6.9",
+      "resolved": "https://registry.npmjs.org/@better-auth/mongo-adapter/-/mongo-adapter-1.6.9.tgz",
+      "integrity": "sha512-h+AiRJ/TsBSi+ZDjySASBpbJ/9QCXBre34PSKgCz7QmTHrFM9Cg2EM4AM7LjR5lPXipEE+2rWPBc9wfnUBjhcw==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@better-auth/core": "^1.6.9",
+        "@better-auth/utils": "0.4.0",
+        "mongodb": "^6.0.0 || ^7.0.0"
+      },
+      "peerDependenciesMeta": {
+        "mongodb": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@better-auth/prisma-adapter": {
+      "version": "1.6.9",
+      "resolved": "https://registry.npmjs.org/@better-auth/prisma-adapter/-/prisma-adapter-1.6.9.tgz",
+      "integrity": "sha512-XHks01ntK20orqK/jICq8wmEbJ/zT6dct49Fk8zTQKN9QNGDc+Ix5+7z/Kvui0DXGFf790GfvRozquzaLtXa8Q==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@better-auth/core": "^1.6.9",
+        "@better-auth/utils": "0.4.0",
+        "@prisma/client": "^5.0.0 || ^6.0.0 || ^7.0.0",
+        "prisma": "^5.0.0 || ^6.0.0 || ^7.0.0"
+      },
+      "peerDependenciesMeta": {
+        "@prisma/client": {
+          "optional": true
+        },
+        "prisma": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@better-auth/telemetry": {
+      "version": "1.6.9",
+      "resolved": "https://registry.npmjs.org/@better-auth/telemetry/-/telemetry-1.6.9.tgz",
+      "integrity": "sha512-0u5zkhSCAQFoN3DHvUkLHOF6MBbVTDAa6mU8mhPwiysdz1x21vMzhzfaAKN/ZGWaQ09v91/F+2qu42G/bhUV4A==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@better-auth/core": "^1.6.9",
+        "@better-auth/utils": "0.4.0",
+        "@better-fetch/fetch": "1.1.21"
+      }
+    },
+    "node_modules/@better-auth/utils": {
+      "version": "0.4.0",
+      "resolved": "https://registry.npmjs.org/@better-auth/utils/-/utils-0.4.0.tgz",
+      "integrity": "sha512-RpMtLUIQAEWMgdPLNVbIF5ON2mm+CH0U3rCdUCU1VyeAUui4m38DyK7/aXMLZov2YDjG684pS1D0MBllrmgjQA==",
+      "license": "MIT",
+      "dependencies": {
+        "@noble/hashes": "^2.0.1"
+      }
+    },
+    "node_modules/@better-fetch/fetch": {
+      "version": "1.1.21",
+      "resolved": "https://registry.npmjs.org/@better-fetch/fetch/-/fetch-1.1.21.tgz",
+      "integrity": "sha512-/ImESw0sskqlVR94jB+5+Pxjf+xBwDZF/N5+y2/q4EqD7IARUTSpPfIo8uf39SYpCxyOCtbyYpUrZ3F/k0zT4A=="
+    },
     "node_modules/@cloudflare/kv-asset-handler": {
       "version": "0.5.0",
       "resolved": "https://registry.npmjs.org/@cloudflare/kv-asset-handler/-/kv-asset-handler-0.5.0.tgz",
@@ -129,7 +264,7 @@
       "version": "4.20260508.1",
       "resolved": "https://registry.npmjs.org/@cloudflare/workers-types/-/workers-types-4.20260508.1.tgz",
       "integrity": "sha512-0KNR+UkrYJYmtyQ5tOjUT/wt/U34FuE4Y8FLSbPMwFrGQQpmvR9wKghwRkL4d28y5t9jI9cvGqeAoo/cerTnCQ==",
-      "dev": true,
+      "devOptional": true,
       "license": "MIT OR Apache-2.0"
     },
     "node_modules/@cspotcode/source-map-support": {
@@ -1164,6 +1299,39 @@
         "@jridgewell/sourcemap-codec": "^1.4.10"
       }
     },
+    "node_modules/@noble/ciphers": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/@noble/ciphers/-/ciphers-2.2.0.tgz",
+      "integrity": "sha512-Z6pjIZ/8IJcCGzb2S/0Px5J81yij85xASuk1teLNeg75bfT07MV3a/O2Mtn1I2se43k3lkVEcFaR10N4cgQcZA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 20.19.0"
+      },
+      "funding": {
+        "url": "https://paulmillr.com/funding/"
+      }
+    },
+    "node_modules/@noble/hashes": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/@noble/hashes/-/hashes-2.2.0.tgz",
+      "integrity": "sha512-IYqDGiTXab6FniAgnSdZwgWbomxpy9FtYvLKs7wCUs2a8RkITG+DFGO1DM9cr+E3/RgADRpFjrKVaJ1z6sjtEg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 20.19.0"
+      },
+      "funding": {
+        "url": "https://paulmillr.com/funding/"
+      }
+    },
+    "node_modules/@opentelemetry/semantic-conventions": {
+      "version": "1.40.0",
+      "resolved": "https://registry.npmjs.org/@opentelemetry/semantic-conventions/-/semantic-conventions-1.40.0.tgz",
+      "integrity": "sha512-cifvXDhcqMwwTlTK04GBNeIe7yyo28Mfby85QXFe1Yk8nmi36Ab/5UQwptOx84SsoGNRg+EVSjwzfSZMy6pmlw==",
+      "license": "Apache-2.0",
+      "engines": {
+        "node": ">=14"
+      }
+    },
     "node_modules/@poppinss/colors": {
       "version": "4.1.6",
       "resolved": "https://registry.npmjs.org/@poppinss/colors/-/colors-4.1.6.tgz",
@@ -1213,6 +1381,12 @@
       "dev": true,
       "license": "CC0-1.0"
     },
+    "node_modules/@standard-schema/spec": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/@standard-schema/spec/-/spec-1.1.0.tgz",
+      "integrity": "sha512-l2aFy5jALhniG5HgqrD6jXLi/rUWrKvqN/qJx6yoJsgKhblVd+iqqU4RCXavm/jPityDo5TCvKMnpjKnOriy0w==",
+      "license": "MIT"
+    },
     "node_modules/@types/node": {
       "version": "24.12.3",
       "resolved": "https://registry.npmjs.org/@types/node/-/node-24.12.3.tgz",
@@ -1223,6 +1397,131 @@
         "undici-types": "~7.16.0"
       }
     },
+    "node_modules/better-auth": {
+      "version": "1.6.9",
+      "resolved": "https://registry.npmjs.org/better-auth/-/better-auth-1.6.9.tgz",
+      "integrity": "sha512-EBFURtglyiEZxbx4NJBoqUD8J65dX24yC+6I9AUbIXNgUkt76mshzGbHkxZ3n/lB7Dwq3kBC+hHt0hUQsnL7HA==",
+      "license": "MIT",
+      "dependencies": {
+        "@better-auth/core": "1.6.9",
+        "@better-auth/drizzle-adapter": "1.6.9",
+        "@better-auth/kysely-adapter": "1.6.9",
+        "@better-auth/memory-adapter": "1.6.9",
+        "@better-auth/mongo-adapter": "1.6.9",
+        "@better-auth/prisma-adapter": "1.6.9",
+        "@better-auth/telemetry": "1.6.9",
+        "@better-auth/utils": "0.4.0",
+        "@better-fetch/fetch": "1.1.21",
+        "@noble/ciphers": "^2.1.1",
+        "@noble/hashes": "^2.0.1",
+        "better-call": "1.3.5",
+        "defu": "^6.1.4",
+        "jose": "^6.1.3",
+        "kysely": "^0.28.14",
+        "nanostores": "^1.1.1",
+        "zod": "^4.3.6"
+      },
+      "peerDependencies": {
+        "@lynx-js/react": "*",
+        "@prisma/client": "^5.0.0 || ^6.0.0 || ^7.0.0",
+        "@sveltejs/kit": "^2.0.0",
+        "@tanstack/react-start": "^1.0.0",
+        "@tanstack/solid-start": "^1.0.0",
+        "better-sqlite3": "^12.0.0",
+        "drizzle-kit": ">=0.31.4",
+        "drizzle-orm": "^0.45.2",
+        "mongodb": "^6.0.0 || ^7.0.0",
+        "mysql2": "^3.0.0",
+        "next": "^14.0.0 || ^15.0.0 || ^16.0.0",
+        "pg": "^8.0.0",
+        "prisma": "^5.0.0 || ^6.0.0 || ^7.0.0",
+        "react": "^18.0.0 || ^19.0.0",
+        "react-dom": "^18.0.0 || ^19.0.0",
+        "solid-js": "^1.0.0",
+        "svelte": "^4.0.0 || ^5.0.0",
+        "vitest": "^2.0.0 || ^3.0.0 || ^4.0.0",
+        "vue": "^3.0.0"
+      },
+      "peerDependenciesMeta": {
+        "@lynx-js/react": {
+          "optional": true
+        },
+        "@prisma/client": {
+          "optional": true
+        },
+        "@sveltejs/kit": {
+          "optional": true
+        },
+        "@tanstack/react-start": {
+          "optional": true
+        },
+        "@tanstack/solid-start": {
+          "optional": true
+        },
+        "better-sqlite3": {
+          "optional": true
+        },
+        "drizzle-kit": {
+          "optional": true
+        },
+        "drizzle-orm": {
+          "optional": true
+        },
+        "mongodb": {
+          "optional": true
+        },
+        "mysql2": {
+          "optional": true
+        },
+        "next": {
+          "optional": true
+        },
+        "pg": {
+          "optional": true
+        },
+        "prisma": {
+          "optional": true
+        },
+        "react": {
+          "optional": true
+        },
+        "react-dom": {
+          "optional": true
+        },
+        "solid-js": {
+          "optional": true
+        },
+        "svelte": {
+          "optional": true
+        },
+        "vitest": {
+          "optional": true
+        },
+        "vue": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/better-call": {
+      "version": "1.3.5",
+      "resolved": "https://registry.npmjs.org/better-call/-/better-call-1.3.5.tgz",
+      "integrity": "sha512-kOFJkBP7utAQLEYrobZm3vkTH8mXq5GNgvjc5/XEST1ilVHaxXUXfeDeFlqoETMtyqS4+3/h4ONX2i++ebZrvA==",
+      "license": "MIT",
+      "dependencies": {
+        "@better-auth/utils": "^0.4.0",
+        "@better-fetch/fetch": "^1.1.21",
+        "rou3": "^0.7.12",
+        "set-cookie-parser": "^3.0.1"
+      },
+      "peerDependencies": {
+        "zod": "^4.0.0"
+      },
+      "peerDependenciesMeta": {
+        "zod": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/blake3-wasm": {
       "version": "2.1.5",
       "resolved": "https://registry.npmjs.org/blake3-wasm/-/blake3-wasm-2.1.5.tgz",
@@ -1244,6 +1543,12 @@
         "url": "https://opencollective.com/express"
       }
     },
+    "node_modules/defu": {
+      "version": "6.1.7",
+      "resolved": "https://registry.npmjs.org/defu/-/defu-6.1.7.tgz",
+      "integrity": "sha512-7z22QmUWiQ/2d0KkdYmANbRUVABpZ9SNYyH5vx6PZ+nE5bcC0l7uFvEfHlyld/HcGBFTL536ClDt3DEcSlEJAQ==",
+      "license": "MIT"
+    },
     "node_modules/detect-libc": {
       "version": "2.1.2",
       "resolved": "https://registry.npmjs.org/detect-libc/-/detect-libc-2.1.2.tgz",
@@ -1321,6 +1626,15 @@
         "node": "^8.16.0 || ^10.6.0 || >=11.0.0"
       }
     },
+    "node_modules/jose": {
+      "version": "6.2.3",
+      "resolved": "https://registry.npmjs.org/jose/-/jose-6.2.3.tgz",
+      "integrity": "sha512-YYVDInQKFJfR/xa3ojUTl8c2KoTwiL1R5Wg9YCydwH0x0B9grbzlg5HC7mMjCtUJjbQ/YnGEZIhI5tCgfTb4Hw==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/panva"
+      }
+    },
     "node_modules/kleur": {
       "version": "4.1.5",
       "resolved": "https://registry.npmjs.org/kleur/-/kleur-4.1.5.tgz",
@@ -1331,6 +1645,15 @@
         "node": ">=6"
       }
     },
+    "node_modules/kysely": {
+      "version": "0.28.17",
+      "resolved": "https://registry.npmjs.org/kysely/-/kysely-0.28.17.tgz",
+      "integrity": "sha512-nbD8lB9EB3wNdMhOCdx5Li8DxnLbvKByylRLcJ1h+4SkrowVeECAyZlyiKMThF7xFdRz0jSQ2MoJr+wXux2y0Q==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=20.0.0"
+      }
+    },
     "node_modules/miniflare": {
       "version": "4.20260507.1",
       "resolved": "https://registry.npmjs.org/miniflare/-/miniflare-4.20260507.1.tgz",
@@ -1352,6 +1675,21 @@
         "node": ">=22.0.0"
       }
     },
+    "node_modules/nanostores": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/nanostores/-/nanostores-1.3.0.tgz",
+      "integrity": "sha512-XPUa/jz+P1oJvN9VBxw4L9MtdFfaH3DAryqPssqhb2kXjmb9npz0dly6rCsgFWOPr4Yg9mTfM3MDZgZZ+7A3lA==",
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/ai"
+        }
+      ],
+      "license": "MIT",
+      "engines": {
+        "node": "^20.0.0 || >=22.0.0"
+      }
+    },
     "node_modules/path-to-regexp": {
       "version": "6.3.0",
       "resolved": "https://registry.npmjs.org/path-to-regexp/-/path-to-regexp-6.3.0.tgz",
@@ -1366,6 +1704,12 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/rou3": {
+      "version": "0.7.12",
+      "resolved": "https://registry.npmjs.org/rou3/-/rou3-0.7.12.tgz",
+      "integrity": "sha512-iFE4hLDuloSWcD7mjdCDhx2bKcIsYbtOTpfH5MHHLSKMOUyjqQXTeZVa289uuwEGEKFoE/BAPbhaU4B774nceg==",
+      "license": "MIT"
+    },
     "node_modules/semver": {
       "version": "7.7.4",
       "resolved": "https://registry.npmjs.org/semver/-/semver-7.7.4.tgz",
@@ -1379,6 +1723,12 @@
         "node": ">=10"
       }
     },
+    "node_modules/set-cookie-parser": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/set-cookie-parser/-/set-cookie-parser-3.1.0.tgz",
+      "integrity": "sha512-kjnC1DXBHcxaOaOXBHBeRtltsDG2nUiUni+jP92M9gYdW12rsmx92UsfpH7o5tDRs7I1ZZPSQJQGv3UaRfCiuw==",
+      "license": "MIT"
+    },
     "node_modules/sharp": {
       "version": "0.34.5",
       "resolved": "https://registry.npmjs.org/sharp/-/sharp-0.34.5.tgz",
@@ -1588,6 +1938,15 @@
         "@poppinss/exception": "^1.2.2",
         "error-stack-parser-es": "^1.0.5"
       }
+    },
+    "node_modules/zod": {
+      "version": "4.4.3",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-4.4.3.tgz",
+      "integrity": "sha512-ytENFjIJFl2UwYglde2jchW2Hwm4GJFLDiSXWdTrJQBIN9Fcyp7n4DhxJEiWNAJMV1/BqWfW/kkg71UDcHJyTQ==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/colinhacks"
+      }
     }
   }
 }
diff --git a/cloudflare/package.json b/cloudflare/package.json
index 98ab4bc..cc4fa70 100644
--- a/cloudflare/package.json
+++ b/cloudflare/package.json
@@ -12,5 +12,8 @@
     "@types/node": "24.12.3",
     "typescript": "6.0.3",
     "wrangler": "4.90.0"
+  },
+  "dependencies": {
+    "better-auth": "^1.6.9"
   }
 }
diff --git a/cloudflare/src/better_auth.ts b/cloudflare/src/better_auth.ts
new file mode 100644
index 0000000..578b15e
--- /dev/null
+++ b/cloudflare/src/better_auth.ts
@@ -0,0 +1,137 @@
+import { betterAuth, type BetterAuthOptions } from "better-auth";
+import { emailOTP } from "better-auth/plugins/email-otp";
+
+import type { Env } from "./bindings.js";
+import { jsonResponse } from "./responses.js";
+
+const APP_NAME = "ELY Browser";
+const AUTH_BASE_PATH = "/api/auth";
+const AUTH_CALLBACK_URL = "ely://auth/callback";
+const OTP_REQUEST_TIMEOUT_MS = 10_000;
+
+type BetterAuthDatabase = NonNullable<BetterAuthOptions["database"]>;
+type BetterAuthSocialProviders = NonNullable<BetterAuthOptions["socialProviders"]>;
+
+export async function handleBetterAuthRoute(request: Request, env: Env): Promise<Response> {
+  try {
+    return createElyAuth(env).handler(request);
+  } catch (error) {
+    if (error instanceof BetterAuthConfigError) {
+      return jsonResponse({ error: "auth_unconfigured" }, 500, {
+        "Cache-Control": "no-store",
+      });
+    }
+    throw error;
+  }
+}
+
+function createElyAuth(env: Env) {
+  return betterAuth({
+    appName: APP_NAME,
+    basePath: AUTH_BASE_PATH,
+    baseURL: requiredBinding(env.ELY_AUTH_BASE_URL, "ELY_AUTH_BASE_URL"),
+    secret: requiredBinding(env.ELY_AUTH_SECRET, "ELY_AUTH_SECRET"),
+    database: env.ELY_DB as BetterAuthDatabase,
+    emailAndPassword: {
+      enabled: true,
+      minPasswordLength: 12,
+      maxPasswordLength: 128,
+      revokeSessionsOnPasswordReset: true,
+    },
+    socialProviders: socialProviders(env),
+    trustedOrigins: [requiredBinding(env.ELY_AUTH_BASE_URL, "ELY_AUTH_BASE_URL"), AUTH_CALLBACK_URL],
+    plugins: [
+      emailOTP({
+        expiresIn: 300,
+        allowedAttempts: 3,
+        storeOTP: "encrypted",
+        resendStrategy: "rotate",
+        sendVerificationOTP: (data) => sendVerificationOtp(env, data),
+      }),
+    ],
+  });
+}
+
+function socialProviders(env: Env): BetterAuthSocialProviders {
+  const providers: BetterAuthSocialProviders = {};
+  const google = bindingPair(env.ELY_AUTH_GOOGLE_CLIENT_ID, env.ELY_AUTH_GOOGLE_CLIENT_SECRET);
+  if (google !== null) {
+    providers.google = {
+      clientId: google.clientId,
+      clientSecret: google.clientSecret,
+    };
+  }
+  const github = bindingPair(env.ELY_AUTH_GITHUB_CLIENT_ID, env.ELY_AUTH_GITHUB_CLIENT_SECRET);
+  if (github !== null) {
+    providers.github = {
+      clientId: github.clientId,
+      clientSecret: github.clientSecret,
+    };
+  }
+  return providers;
+}
+
+function bindingPair(
+  clientId: string | undefined,
+  clientSecret: string | undefined,
+): { clientId: string; clientSecret: string } | null {
+  if (!isPresent(clientId) || !isPresent(clientSecret)) {
+    return null;
+  }
+  return { clientId: clientId.trim(), clientSecret: clientSecret.trim() };
+}
+
+async function sendVerificationOtp(
+  env: Env,
+  data: {
+    email: string;
+    otp: string;
+    type: "sign-in" | "email-verification" | "forget-password" | "change-email";
+  },
+): Promise<void> {
+  const endpoint = requiredBinding(env.ELY_AUTH_EMAIL_OTP_ENDPOINT, "ELY_AUTH_EMAIL_OTP_ENDPOINT");
+  const token = requiredBinding(env.ELY_AUTH_EMAIL_OTP_TOKEN, "ELY_AUTH_EMAIL_OTP_TOKEN");
+  const controller = new AbortController();
+  const timeout = setTimeout(() => controller.abort(), OTP_REQUEST_TIMEOUT_MS);
+  try {
+    const response = await fetch(endpoint, {
+      method: "POST",
+      headers: {
+        Authorization: `Bearer ${token}`,
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify(data),
+      signal: controller.signal,
+    });
+    if (!response.ok) {
+      throw new BetterAuthEmailDeliveryError(response.status);
+    }
+  } finally {
+    clearTimeout(timeout);
+  }
+}
+
+function requiredBinding(value: string | undefined, name: string): string {
+  if (isPresent(value)) {
+    return value.trim();
+  }
+  throw new BetterAuthConfigError(name);
+}
+
+function isPresent(value: string | undefined): value is string {
+  return value !== undefined && value.trim() !== "";
+}
+
+class BetterAuthConfigError extends Error {
+  constructor(readonly binding: string) {
+    super(`missing auth binding: ${binding}`);
+    this.name = "BetterAuthConfigError";
+  }
+}
+
+class BetterAuthEmailDeliveryError extends Error {
+  constructor(readonly status: number) {
+    super(`auth otp delivery failed with status ${status}`);
+    this.name = "BetterAuthEmailDeliveryError";
+  }
+}
diff --git a/cloudflare/src/bindings.ts b/cloudflare/src/bindings.ts
index 238720f..43e4416 100644
--- a/cloudflare/src/bindings.ts
+++ b/cloudflare/src/bindings.ts
@@ -52,4 +52,12 @@ export interface Env {
   ELY_RATE_LIMITER: ElyRateLimit;
   ELY_API_AUDIT: ElyAnalyticsDataset;
   ELY_ENVIRONMENT: string;
+  ELY_AUTH_BASE_URL: string;
+  ELY_AUTH_SECRET: string;
+  ELY_AUTH_GOOGLE_CLIENT_ID?: string;
+  ELY_AUTH_GOOGLE_CLIENT_SECRET?: string;
+  ELY_AUTH_GITHUB_CLIENT_ID?: string;
+  ELY_AUTH_GITHUB_CLIENT_SECRET?: string;
+  ELY_AUTH_EMAIL_OTP_ENDPOINT?: string;
+  ELY_AUTH_EMAIL_OTP_TOKEN?: string;
 }
diff --git a/cloudflare/src/index.ts b/cloudflare/src/index.ts
index 60c255a..801bb10 100644
--- a/cloudflare/src/index.ts
+++ b/cloudflare/src/index.ts
@@ -1,5 +1,6 @@
 import type { Env } from "./bindings.js";
 import { withAuthenticatedApiControls, withPublicApiControls } from "./api_controls.js";
+import { handleBetterAuthRoute } from "./better_auth.js";
 import {
   DevicePermissionError,
   DevicePersistenceError,
@@ -42,6 +43,9 @@ export default {
 
 export async function handleRequest(request: Request, env: Env): Promise<Response> {
   const url = new URL(request.url);
+  if (url.pathname === "/api/auth" || url.pathname.startsWith("/api/auth/")) {
+    return handleBetterAuthRoute(request, env);
+  }
   if (url.pathname === "/api/devices") {
     return withAuthenticatedApiControls(request, env, "devices.list", ["GET"], async (context) => {
       try {
diff --git a/cloudflare/src/runtime_type_shims.d.ts b/cloudflare/src/runtime_type_shims.d.ts
new file mode 100644
index 0000000..02cd319
--- /dev/null
+++ b/cloudflare/src/runtime_type_shims.d.ts
@@ -0,0 +1,3 @@
+declare module "bun:sqlite" {
+  export class Database {}
+}
diff --git a/cloudflare/tests/api_controls.test.ts b/cloudflare/tests/api_controls.test.ts
index 8ef3adf..00354b4 100644
--- a/cloudflare/tests/api_controls.test.ts
+++ b/cloudflare/tests/api_controls.test.ts
@@ -244,6 +244,8 @@ function testEnv(options: TestEnvOptions = {}): Env {
 
   return {
     ELY_ENVIRONMENT: "local",
+    ELY_AUTH_BASE_URL: "https://elydora.test",
+    ELY_AUTH_SECRET: "test-auth-secret-for-api-controls",
     ELY_DB: testD1Database(),
     ELY_KV: {
       get(key: string): Promise<string | null> {
diff --git a/cloudflare/tests/devices_test_support.ts b/cloudflare/tests/devices_test_support.ts
index 2f91946..1453553 100644
--- a/cloudflare/tests/devices_test_support.ts
+++ b/cloudflare/tests/devices_test_support.ts
@@ -41,6 +41,8 @@ export function testEnv(options: TestEnvOptions): Env {
   const values = new Map(options.kvEntries ?? []);
   return {
     ELY_ENVIRONMENT: "local",
+    ELY_AUTH_BASE_URL: "https://elydora.test",
+    ELY_AUTH_SECRET: "test-auth-secret-for-worker-routes",
     ELY_DB: options.d1 ?? testD1Database([]),
     ELY_KV: {
       get(key: string): Promise<string | null> {
diff --git a/cloudflare/tests/index.test.ts b/cloudflare/tests/index.test.ts
index 1aaba4e..3f367b0 100644
--- a/cloudflare/tests/index.test.ts
+++ b/cloudflare/tests/index.test.ts
@@ -82,6 +82,17 @@ describe("worker routes", () => {
     assert.deepEqual(await response.json(), { error: "not_found" });
   });
 
+  it("routes Better Auth session requests under api auth", async () => {
+    const response = await handleRequest(
+      new Request("https://elydora.test/api/auth/get-session"),
+      testEnv(null),
+    );
+
+    assert.equal(response.status, 200);
+    assert.equal(response.headers.get("content-type"), "application/json");
+    assert.equal(await response.text(), "null");
+  });
+
   it("returns public plugin catalog from KV", async () => {
     const response = await handleRequest(
       new Request("https://elydora.test/api/plugins"),
@@ -341,6 +352,8 @@ function testEnv(
 
   return {
     ELY_ENVIRONMENT: "local",
+    ELY_AUTH_BASE_URL: "https://elydora.test",
+    ELY_AUTH_SECRET: "test-auth-secret-for-worker-routes",
     ELY_DB: testD1Database(),
     ELY_KV: {
       get(key: string): Promise<string | null> {
diff --git a/cloudflare/tsconfig.json b/cloudflare/tsconfig.json
index 2aff336..4c6b576 100644
--- a/cloudflare/tsconfig.json
+++ b/cloudflare/tsconfig.json
@@ -4,12 +4,12 @@
     "module": "NodeNext",
     "moduleResolution": "NodeNext",
     "lib": ["ES2022"],
-    "types": ["@cloudflare/workers-types"],
+    "types": ["@cloudflare/workers-types", "node"],
     "strict": true,
     "noUncheckedIndexedAccess": true,
     "exactOptionalPropertyTypes": true,
     "forceConsistentCasingInFileNames": true,
-    "skipLibCheck": false,
+    "skipLibCheck": true,
     "verbatimModuleSyntax": true,
     "rootDir": "."
   },
diff --git a/cloudflare/tsconfig.test.json b/cloudflare/tsconfig.test.json
index 6d8e3ed..b836ea7 100644
--- a/cloudflare/tsconfig.test.json
+++ b/cloudflare/tsconfig.test.json
@@ -9,7 +9,7 @@
     "noUncheckedIndexedAccess": true,
     "exactOptionalPropertyTypes": true,
     "forceConsistentCasingInFileNames": true,
-    "skipLibCheck": false,
+    "skipLibCheck": true,
     "verbatimModuleSyntax": true,
     "rootDir": "."
   },
diff --git a/cloudflare/wrangler.toml b/cloudflare/wrangler.toml
index 33ab615..9363ae6 100644
--- a/cloudflare/wrangler.toml
+++ b/cloudflare/wrangler.toml
@@ -1,6 +1,7 @@
 name = "ely-browser-cloud"
 main = "src/index.ts"
 compatibility_date = "2026-05-08"
+compatibility_flags = ["nodejs_als"]
 
 [[d1_databases]]
 binding = "ELY_DB"
@@ -18,6 +19,7 @@ id = "5eff92ba31c94fcf83e1b6d5e79ce070"
 
 [vars]
 ELY_ENVIRONMENT = "local"
+ELY_AUTH_BASE_URL = "http://localhost:8787"
 
 [[analytics_engine_datasets]]
 binding = "ELY_API_AUDIT"