diff --git a/migrations/036_users.sql b/migrations/036_users.sql
new file mode 100644
index 0000000..d82a477
--- /dev/null
+++ b/migrations/036_users.sql
@@ -0,0 +1,12 @@
+-- Locally-issued player accounts. GUPI mints the JWT for now; external_id is
+-- reserved so a glitch.university key-exchange can later link/migrate an account
+-- without changing how playthroughs bind (they key off the JWT sub = users.id).
+CREATE TABLE osint.users (
+  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  handle TEXT NOT NULL UNIQUE CHECK (handle ~ '^[a-z0-9_.-]{3,32}$'),
+  password_hash TEXT NOT NULL,
+  display_name TEXT NOT NULL,
+  avatar_url TEXT,
+  external_id TEXT UNIQUE,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
diff --git a/server/auth.ts b/server/auth.ts
index 7982c84..bdc4b17 100644
--- a/server/auth.ts
+++ b/server/auth.ts
@@ -49,6 +49,13 @@ export function requireAdmin(req: Request, res: Response, next: NextFunction) {
   next()
 }
 
+// Mint a player token (path A: GUPI is the issuer for now). Verification is
+// issuer-agnostic — a glitch.university token with the same sub verifies identically.
+export function signPlayerToken(user: { id: string; displayName: string }) {
+  if (!process.env.JWT_SECRET) throw new Error('JWT_SECRET is required')
+  return jwt.sign({ sub: user.id, name: user.displayName, role: 'player' }, process.env.JWT_SECRET, { expiresIn: '30d' })
+}
+
 export function createDevelopmentAdminToken() {
   if (process.env.NODE_ENV === 'production') throw new Error('Development sessions are disabled in production')
   if (!process.env.JWT_SECRET) throw new Error('JWT_SECRET is required')
diff --git a/server/index.ts b/server/index.ts
index 3793364..8c4fc0e 100644
--- a/server/index.ts
+++ b/server/index.ts
@@ -8,7 +8,8 @@ import { fileURLToPath } from 'node:url'
 import multer from 'multer'
 import pg from 'pg'
 import type { CaseState } from '../src/types.js'
-import { authenticateJwt, createDevelopmentAdminToken, hasAdminClaim, requireAdmin, resolvePlayerName, resolveUserId } from './auth.js'
+import { authenticateJwt, createDevelopmentAdminToken, hasAdminClaim, requireAdmin, resolvePlayerName, resolveUserId, signPlayerToken } from './auth.js'
+import { createUserRepository } from './userRepository.js'
 import { submitCaseReport } from './caseReports.js'
 import { createLevelRepository } from './levelRepository.js'
 import { createEvidenceJudgeFromEnv } from './evidenceJudge.js'
@@ -33,6 +34,8 @@ const evidenceJudge = createEvidenceJudgeFromEnv()
 const levels = createLevelRepository(pool, editingEnabled, objectStorage, evidenceJudge)
 const narrative = createNarrativeRepository(pool, objectStorage)
 const storyGraph = createStoryGraphRepository(pool)
+const users = createUserRepository(pool)
+const AUTH_COOKIE = { httpOnly: true, sameSite: 'lax' as const, path: '/', maxAge: 30 * 24 * 60 * 60 * 1000 }
 const STORY_NODE_TYPES: StoryNodeType[] = ['cutscene', 'dialogue', 'level', 'det_gate', 'llm_gate', 'merit', 'phone']
 
 function wantsEdit(req: express.Request) {
@@ -59,6 +62,35 @@ app.get('/api/health', async (_req, res) => {
   catch { res.status(503).json({ ok: false, database: 'unavailable' }) }
 })
 app.get('/api/session', (req, res) => res.json({ authenticated: Boolean(req.authClaims), isAdmin: hasAdminClaim(req), playerName:resolvePlayerName(req) }))
+
+// Player accounts (path A: GUPI issues the token). register/login set the auth_token
+// cookie; every game write then binds to this user via resolveUserId.
+app.post('/api/auth/register', async (req, res, next) => {
+  try {
+    const body = req.body || {}
+    const result = await users.registerUser({ handle: String(body.handle || ''), password: String(body.password || ''), displayName: String(body.displayName || '') })
+    if (result.error || !result.user) return res.status(result.error === 'That handle is taken' ? 409 : 400).json({ error: result.error || 'Registration failed' })
+    res.cookie('auth_token', signPlayerToken(result.user), AUTH_COOKIE)
+    res.status(201).json({ user: result.user })
+  } catch (error) { next(error) }
+})
+app.post('/api/auth/login', async (req, res, next) => {
+  try {
+    const body = req.body || {}
+    const user = await users.authenticateUser(String(body.handle || ''), String(body.password || ''))
+    if (!user) return res.status(401).json({ error: 'Invalid handle or password' })
+    res.cookie('auth_token', signPlayerToken(user), AUTH_COOKIE)
+    res.json({ user })
+  } catch (error) { next(error) }
+})
+app.post('/api/auth/logout', (_req, res) => { res.clearCookie('auth_token', { path: '/' }); res.json({ ok: true }) })
+app.get('/api/auth/me', async (req, res, next) => {
+  try {
+    const sub = req.authClaims?.sub
+    const user = typeof sub === 'string' ? await users.getUser(sub) : null
+    user ? res.json({ user }) : res.status(204).end()
+  } catch (error) { next(error) }
+})
 if (process.env.NODE_ENV !== 'production') app.get('/api/dev/admin-session', (req, res) => {
   const requestedReturn = String(req.query.returnTo || '/')
   const returnTo = requestedReturn.startsWith('/') && !requestedReturn.startsWith('//') ? requestedReturn : '/'
diff --git a/server/userRepository.ts b/server/userRepository.ts
new file mode 100644
index 0000000..8f5ed92
--- /dev/null
+++ b/server/userRepository.ts
@@ -0,0 +1,60 @@
+import { randomBytes, scryptSync, timingSafeEqual } from 'node:crypto'
+import type { Pool } from 'pg'
+
+export type UserDto = { id: string; handle: string; displayName: string; avatarUrl: string | null }
+
+export interface UserRepository {
+  registerUser(input: { handle: string; password: string; displayName: string }): Promise<{ user?: UserDto; error?: string }>
+  authenticateUser(handle: string, password: string): Promise<UserDto | null>
+  getUser(id: string): Promise<UserDto | null>
+}
+
+const HANDLE = /^[a-z0-9_.-]{3,32}$/
+
+// scrypt with a per-user random salt; stored as `salt:hash` hex. No dependency.
+function hashPassword(password: string): string {
+  const salt = randomBytes(16)
+  return `${salt.toString('hex')}:${scryptSync(password, salt, 64).toString('hex')}`
+}
+function verifyPassword(password: string, stored: string): boolean {
+  const [saltHex, hashHex] = stored.split(':')
+  if (!saltHex || !hashHex) return false
+  const expected = Buffer.from(hashHex, 'hex')
+  const actual = scryptSync(password, Buffer.from(saltHex, 'hex'), 64)
+  return expected.length === actual.length && timingSafeEqual(expected, actual)
+}
+
+export function createUserRepository(pool: Pool): UserRepository {
+  const toDto = (row: { id: string; handle: string; display_name: string; avatar_url: string | null }): UserDto =>
+    ({ id: row.id, handle: row.handle, displayName: row.display_name, avatarUrl: row.avatar_url })
+
+  return {
+    async registerUser({ handle: rawHandle, password, displayName: rawName }) {
+      const handle = rawHandle.trim().toLowerCase()
+      const displayName = rawName.trim().slice(0, 60)
+      if (!HANDLE.test(handle)) return { error: 'Handle must be 3–32 chars: a–z, 0–9, . _ -' }
+      if (password.length < 6) return { error: 'Password must be at least 6 characters' }
+      if (!displayName) return { error: 'A display name is required' }
+      const existing = await pool.query('SELECT 1 FROM osint.users WHERE handle=$1', [handle])
+      if (existing.rowCount) return { error: 'That handle is taken' }
+      const row = (await pool.query<{ id: string; handle: string; display_name: string; avatar_url: string | null }>(
+        'INSERT INTO osint.users (handle,password_hash,display_name) VALUES ($1,$2,$3) RETURNING id,handle,display_name,avatar_url',
+        [handle, hashPassword(password), displayName])).rows[0]
+      return { user: toDto(row) }
+    },
+
+    async authenticateUser(rawHandle, password) {
+      const handle = rawHandle.trim().toLowerCase()
+      const row = (await pool.query<{ id: string; handle: string; display_name: string; avatar_url: string | null; password_hash: string }>(
+        'SELECT id,handle,display_name,avatar_url,password_hash FROM osint.users WHERE handle=$1', [handle])).rows[0]
+      if (!row || !verifyPassword(password, row.password_hash)) return null
+      return toDto(row)
+    },
+
+    async getUser(id) {
+      const row = (await pool.query<{ id: string; handle: string; display_name: string; avatar_url: string | null }>(
+        'SELECT id,handle,display_name,avatar_url FROM osint.users WHERE id=$1', [id])).rows[0]
+      return row ? toDto(row) : null
+    },
+  }
+}