Better Auth → UserTrack in two minutes.

Supported: better-auth ≥ 1.3.0 · ESM · Node 18.17+ and edge runtimes with WebCrypto · any database adapter that implements count (others fall back to a bounded id-only scan).

1. 1 · Create the integration in UserTrack

   Project → Integrations → Users → Better Auth. Enter your Better Auth base URL (baseURL + basePath, usually /api/auth). UserTrack generates USERTRACK_PROJECT_ID and a USERTRACK_SECRET (ut_int_…, shown once — rotate it if lost).

2. 2 · Install the package
   npmpnpmyarnbun

   npm install @usertrack/better-auth@latest

3. 3 · Add the plugin to your Better Auth config

   import { betterAuth } from "better-auth";
   import { userTrack } from "@usertrack/better-auth";
   
   export const auth = betterAuth({
     // ...your existing options stay unchanged
     plugins: [
       // ...your existing plugins stay unchanged
       userTrack({
         projectId: process.env.USERTRACK_PROJECT_ID!,
         secret: process.env.USERTRACK_SECRET!,
       }),
     ],
   });

4. 4 · Environment variables

   # UserTrack (https://usertrack.dev) — registered-user growth metrics, no PII
   USERTRACK_PROJECT_ID=
   USERTRACK_SECRET=

   Set the real values in your local env file and in your hosting provider for every environment. Never commit the secret.

5. 5 · Deploy, then click Verify

   UserTrack calls your app once, checks the signature, reads the total user count, records the first verified snapshot and schedules syncs every 4 hours. Result: Connected · 12,481 users detected · Verified via Better Auth.

{
  "protocolVersion": 1,
  "clientVersion": "0.2.0",
  "source": "better-auth",
  "projectId": "<USERTRACK_PROJECT_ID>",
  "generatedAt": "2026-09-03T08:00:00.000Z",
  "users": { "totalUsers": 12481, "newUsers": { "24h": 84, "7d": 491, "30d": 1832 }, "daily": [{ "day": "2026-08-04", "newUsers": 51 }, "…"] },
  "capabilities": { "exactCounts": true, "history": true, "anonymousExcluded": false, "roles": ["users"] }
}

Compatibility: UserTrack checks protocolVersion (supported: 1) and clientVersion (minimum 0.1.0; 0.1.x plugins that still send the users-only shape keep working) on every sync and shows an actionable error when the plugin is outdated.

• ›Total registered users and new users in 24h / 7d / 30d, plus a daily series on first sync (aggregate counts only).
• ›Optionally activated users and converted / trial users from the same handler (counts only — never amounts, prices or MRR).
• ›Optional lifecycle events user.created / user.deleted / user.activated / trial.started / user.converted with a pseudonymous HMAC-derived subject — never the user id, email, name or profile.
• ›Never: emails, names, passwords, password hashes, session tokens, verification tokens, account or provider metadata.

Users created by the Better Auth anonymous plugin are excluded from registered-user counts automatically. On your public UserTrack page the source appears only as provenance: Verified via Better Auth. Trust semantics are the same as for every provider: UserTrack independently retrieves aggregate metrics from your installation; it does not claim that every account is a real human.

Connect the UserTrack MCP server (https://usertrack.dev/mcp, token from your developer page) to Claude Code, Cursor, Codex or VS Code and send:

Add this Better Auth project to UserTrack. Create or find the UserTrack project, create the native integration (usertrack_create_integration { provider: "native", source: "better-auth" }), install @usertrack/better-auth with this repo's package manager, add userTrack({ projectId: process.env.USERTRACK_PROJECT_ID!, secret: process.env.USERTRACK_SECRET! }) to the existing Better Auth plugins array without changing any other auth option, add both env vars to .env.example and the local env (never commit the secret), typecheck, deploy, verify the integration, trigger the first sync, publish the project (usertrack_update_project { isPublic: true } — a draft is not listed and its public URL 404s) and return the public UserTrack URL.

The agent calls usertrack_create_integration (receives the secret once), usertrack_get_native_setup with source: "better-auth" (install command for npm / pnpm / yarn / bun, code change, env vars) and usertrack_verify_integration. The instructions it receives include these safety rules:

1. 01Locate the file that calls betterAuth({ ... }) (commonly lib/auth.ts, src/lib/auth.ts, auth.ts, server/auth.ts, or convex/auth.ts). Do not create a second Better Auth instance.
2. 02Add the import { userTrack } from "@usertrack/better-auth" next to the existing imports.
3. 03If a plugins array exists, append userTrack({ ... }) to it; never replace, reorder or remove existing plugins. If none exists, add plugins: [userTrack({ ... })].
4. 04Read projectId and secret from process.env.USERTRACK_PROJECT_ID / process.env.USERTRACK_SECRET (or the framework's env helper). Never hardcode the secret and never commit it.
5. 05Add both variable names to .env.example (values empty) and the real values to the local env file that is git-ignored (.env.local / .env). Add them to the hosting provider's environment for every environment that serves the app.
6. 06Preserve every existing Better Auth option: baseURL, database adapter, emailAndPassword, socialProviders, session settings, hooks and trustedOrigins stay exactly as they were.
7. 07Do not change login, signup or session behaviour. The plugin is observational: it adds one signed endpoint (POST <basePath>/usertrack/metrics) and fire-and-forget lifecycle events.
8. 08Run the project's typecheck and tests after the change; the plugin ships its own types.
9. 09Deploy. UserTrack can only verify once the new build with the env vars is live.

Package source, tests and changelog: github.com/The-CodeCave/UserTrack · npm: @usertrack/better-auth · MIT.