diff --git a/Dockerfile b/Dockerfile
index aa09189..50335db 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -34,6 +34,7 @@ COPY --from=build /workspace/package.json /app/package.json
 COPY --from=build /workspace/node_modules /app/node_modules
 COPY --from=build /workspace/apps/api/package.json /app/apps/api/package.json
 COPY --from=build /workspace/apps/api/dist /app/apps/api/dist
+COPY --from=build /workspace/migrations /app/migrations
 COPY --from=build /workspace/packages/contracts/package.json /app/packages/contracts/package.json
 COPY --from=build /workspace/packages/contracts/dist /app/packages/contracts/dist
 COPY --from=build /workspace/apps/web/dist /app/web
diff --git a/README.md b/README.md
index c840c9f..cb5665b 100644
--- a/README.md
+++ b/README.md
@@ -32,4 +32,4 @@ npm run verify
 docker build -t fieldlens .
 ```
 
-Production migrations are applied explicitly before application deployment. The API runtime account is not expected to perform schema DDL on startup.
+For Arrowstack `database-per-tenant` deployments, the restricted application runtime identity owns DDL inside its dedicated database. The API applies versioned migrations at startup under a PostgreSQL advisory lock before it begins listening; applied migration filenames and checksums are recorded so startup is idempotent and changed historical migrations fail closed.
diff --git a/apps/api/src/migrations.ts b/apps/api/src/migrations.ts
new file mode 100644
index 0000000..cae3701
--- /dev/null
+++ b/apps/api/src/migrations.ts
@@ -0,0 +1,70 @@
+import { createHash } from 'node:crypto'
+import { readdir, readFile } from 'node:fs/promises'
+import path from 'node:path'
+import { pool } from './db.js'
+import { log } from './log.js'
+
+const MIGRATION_LOCK_ID = 884251031
+const migrationsDir = process.env.MIGRATIONS_DIR?.trim() || path.resolve(process.cwd(), 'migrations')
+
+function checksum(sql: string) {
+  return createHash('sha256').update(sql).digest('hex')
+}
+
+export async function runMigrations() {
+  const client = await pool.connect()
+  try {
+    await client.query('SELECT pg_advisory_lock($1)', [MIGRATION_LOCK_ID])
+    await client.query(`
+      CREATE TABLE IF NOT EXISTS fieldlens_schema_migrations (
+        filename text PRIMARY KEY,
+        checksum text NOT NULL,
+        applied_at timestamptz NOT NULL DEFAULT now()
+      )
+    `)
+
+    const files = (await readdir(migrationsDir))
+      .filter((name) => /^\d{3}_.+\.sql$/.test(name))
+      .sort()
+
+    if (files.length === 0) throw new Error('No FieldLens migrations found')
+
+    for (const filename of files) {
+      const sql = await readFile(path.join(migrationsDir, filename), 'utf8')
+      const digest = checksum(sql)
+      const applied = await client.query<{ checksum: string }>(
+        'SELECT checksum FROM fieldlens_schema_migrations WHERE filename = $1',
+        [filename],
+      )
+
+      if (applied.rows[0]) {
+        if (applied.rows[0].checksum !== digest) {
+          throw new Error(`Applied migration checksum mismatch: ${filename}`)
+        }
+        continue
+      }
+
+      await client.query('BEGIN')
+      try {
+        await client.query(sql)
+        await client.query(
+          'INSERT INTO fieldlens_schema_migrations (filename, checksum) VALUES ($1, $2)',
+          [filename, digest],
+        )
+        await client.query('COMMIT')
+        log('info', 'migration_applied', { filename })
+      } catch (error) {
+        await client.query('ROLLBACK')
+        throw error
+      }
+    }
+
+    log('info', 'migrations_ready', { count: files.length })
+  } finally {
+    try {
+      await client.query('SELECT pg_advisory_unlock($1)', [MIGRATION_LOCK_ID])
+    } finally {
+      client.release()
+    }
+  }
+}
diff --git a/apps/api/src/server.ts b/apps/api/src/server.ts
index cbaf3db..c5afd98 100644
--- a/apps/api/src/server.ts
+++ b/apps/api/src/server.ts
@@ -8,6 +8,7 @@ import { config } from './config.js'
 import { loadDeviceContext } from './context.js'
 import { databaseReady, pool } from './db.js'
 import { log } from './log.js'
+import { runMigrations } from './migrations.js'
 import { processSyncEvent } from './sync.js'
 
 const app = express()
@@ -259,6 +260,8 @@ if (config.staticDir) {
   })
 }
 
+await runMigrations()
+
 const server = app.listen(config.port, '0.0.0.0', () => {
   log('info', 'server_started', {
     port: config.port,