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Manual Alembic Database Migration

Overview​

Open WebUI automatically runs database migrations on startup. Manual migration is rarely needed and should only be performed in specific failure scenarios or maintenance situations.

When Manual Migration is Required

You need manual migration only if:

  • Open WebUI logs show specific migration errors during startup
  • You're performing offline database maintenance
  • Automatic migration fails after a version upgrade
  • You're migrating between database types (SQLite ↔ PostgreSQL)
  • A developer has instructed you to run migrations manually
Critical Warning

Manual migration can corrupt your database if performed incorrectly. Always create a verified backup before proceeding.

Prerequisites Checklist​

Before starting, ensure you have:

  • Root/admin access to your Open WebUI installation
  • Database location confirmed (default: /app/backend/data/webui.db in Docker)
  • Open WebUI completely stopped (no running processes)
  • Backup created and verified (see below)
  • Access to container or Python environment where Open WebUI runs
Stop All Processes First

Database migrations cannot run while Open WebUI is active. You must stop all Open WebUI processes before attempting manual migration.

Step 1: Create and Verify Backup​

Backup Your Database​

Terminal
# Find your database location first
docker inspect open-webui | grep -A 5 Mounts

# Create timestamped backup
cp /path/to/webui.db /path/to/webui.db.backup.$(date +%Y%m%d_%H%M%S)

Verify Backup Integrity​

Critical: Test that your backup is readable before proceeding.

Terminal - Verify Backup
# Test backup can be opened
sqlite3 /path/to/webui.db.backup "SELECT count(*) FROM user;"

# Verify schema matches
sqlite3 /path/to/webui.db ".schema" > current-schema.sql
sqlite3 /path/to/webui.db.backup ".schema" > backup-schema.sql
diff current-schema.sql backup-schema.sql
Backup Storage

Store backups on a different disk or volume than your database to protect against disk failure.

Step 2: Diagnose Current State​

Before attempting any fixes, gather information about your database state.

Access Your Environment​

Terminal
# Stop Open WebUI first
docker stop open-webui

# Enter container for diagnostics
docker run --rm -it \
  -v open-webui:/app/backend/data \
  --entrypoint /bin/bash \
  ghcr.io/open-webui/open-webui:main
Verify Your Location

Check where you are after entering the container:

pwd

The Alembic configuration is at /app/backend/open_webui/alembic.ini. Navigate there regardless of your starting directory.

Navigate to the directory containing alembic.ini and configure required environment variables:

Terminal - Navigate and Configure Environment
# First, verify where you are
pwd

# Navigate to Alembic directory (adjust path if your pwd is different)
cd /app/backend/open_webui  # Docker
# OR
cd /path/to/open-webui/backend/open_webui  # Local

# Verify alembic.ini exists in current directory
ls -la alembic.ini

Set Required Environment Variables​

Terminal - Set Environment Variables (Docker)
# Required: Database URL
# For SQLite (4 slashes for absolute path)
export DATABASE_URL="sqlite:////app/backend/data/webui.db"

# For PostgreSQL
export DATABASE_URL="postgresql://user:password@localhost:5432/open_webui_db"

# Required: WEBUI_SECRET_KEY
# Get from existing file
export WEBUI_SECRET_KEY=$(cat /app/backend/data/.webui_secret_key)

# If .webui_secret_key doesn't exist, generate one
# export WEBUI_SECRET_KEY=$(python3 -c "import secrets; print(secrets.token_hex(32))")
# echo $WEBUI_SECRET_KEY > /app/backend/data/.webui_secret_key

# Verify both are set
echo "DATABASE_URL: $DATABASE_URL"
echo "WEBUI_SECRET_KEY: ${WEBUI_SECRET_KEY:0:10}..."
Both Variables Required

Alembic commands will fail with Required environment variable not found if WEBUI_SECRET_KEY is missing. Open WebUI's code imports env.py which validates this variable exists before Alembic can even connect to the database.

Path Syntax for SQLite
  • sqlite:////app/... = 4 slashes total (absolute path: sqlite:// + / + /app/...)
  • sqlite:///../data/... = 3 slashes total (relative path)

Run Diagnostic Commands​

Execute these read-only diagnostic commands:

Terminal - Diagnostics (Safe - Read Only)
# Check current migration version
alembic current -v

# Check target (latest) version
alembic heads

# List all migration history
alembic history

# Show pending migrations (what would be applied)
alembic upgrade head --sql | head -30

# Check for branching (indicates issues)
alembic branches

Expected output:

# alembic current should show something like:
ae1027a6acf (head)

# If you see multiple heads or branching, your migration history has issues
Understanding Output
  • alembic current = what version your database thinks it's at
  • alembic heads = what version the code expects
  • alembic upgrade head --sql = preview SQL that would be executed (doesn't apply changes)
  • If current is older than heads, you have pending migrations
  • If current equals heads, your database is up-to-date
Check Actual Database Tables

Verify what's actually in your database:

Terminal
sqlite3 /app/backend/data/webui.db ".tables"
sqlite3 /app/backend/data/webui.db "SELECT * FROM alembic_version;"

Step 3: Apply Migrations​

Standard Upgrade (Most Common)​

If diagnostics show you have pending migrations (current < heads), upgrade to latest:

Terminal - Upgrade to Latest
# Ensure you're in the correct directory
cd /app/backend/open_webui

# Run upgrade
alembic upgrade head

Watch for these outputs:

INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.runtime.migration] Running upgrade abc123 -> def456, add_new_column
"Will assume non-transactional DDL"

This is a normal informational message for SQLite, not an error. SQLite doesn't support rollback of schema changes, so migrations run without transaction protection.

If the process appears to hang after this message, wait 2-3 minutes - some migrations take time, especially:

  • Migrations that add indexes to large tables (1M+ rows: 1-5 minutes)
  • Migrations with data transformations (100K+ rows: 30 seconds to several minutes)
  • Migrations that rebuild tables (SQLite doesn't support all ALTER operations)

For very large databases (10M+ rows), consider running migrations during a maintenance window and monitoring progress with sqlite3 /path/to/webui.db ".tables" in another terminal.

Upgrade to Specific Version​

If you need to apply migrations up to a specific point:

Terminal - Upgrade to Specific Version
# List available versions first
alembic history

# Upgrade to specific revision
alembic upgrade ae1027a6acf

Downgrade (Rollback)​

Data Loss Risk

Downgrading can cause permanent data loss if the migration removed columns or tables. Only downgrade if you understand the consequences.

Terminal - Downgrade Migrations
# Downgrade one version
alembic downgrade -1

# Downgrade to specific version
alembic downgrade <revision_id>

# Nuclear option: Remove all migrations (rarely needed)
alembic downgrade base

Step 4: Verify Migration Success​

After running migrations, confirm everything is correct:

Terminal - Post-Migration Verification
# Verify current version matches expected
alembic current
# Should show (head) indicating you're at latest
# Example: ae1027a6acf (head)

# Confirm no pending migrations
alembic upgrade head --sql | head -20
# If output contains only comments or is empty, you're up to date

# Verify key tables exist (SQLite)
sqlite3 /app/backend/data/webui.db ".tables" | grep -E "user|chat|model"
# Should show user, chat, model tables among others

# Test a simple query to ensure schema is intact
sqlite3 /app/backend/data/webui.db "SELECT COUNT(*) FROM user;"
# Should return a number, not an error

Test Application Startup​

Terminal
# Exit the diagnostic container
exit

# Start Open WebUI normally
docker start open-webui

# Watch logs for migration confirmation
docker logs -f open-webui

# Look for successful startup, then test in browser
# Navigate to http://localhost:8080 and verify login page loads

Successful startup logs:

INFO:     [db] Database initialization complete
INFO:     [main] Open WebUI starting on http://0.0.0.0:8080

Smoke test after startup:

  • Can access login page
  • Can log in with existing credentials
  • Can view chat history
  • No JavaScript console errors

Troubleshooting​

"Required environment variable not found"​

Cause: WEBUI_SECRET_KEY environment variable is missing.

Solution:

Terminal - Fix Missing Secret Key (Docker)
# Method 1: Use existing key from file
export WEBUI_SECRET_KEY=$(cat /app/backend/data/.webui_secret_key)

# Method 2: If file doesn't exist, generate new key
export WEBUI_SECRET_KEY=$(python3 -c "import secrets; print(secrets.token_hex(32))")
echo $WEBUI_SECRET_KEY > /app/backend/data/.webui_secret_key

# Verify it's set
echo "WEBUI_SECRET_KEY: ${WEBUI_SECRET_KEY:0:10}..."

# Try alembic again
alembic current -v
Why This Happens

Open WebUI's env.py file imports models, which import open_webui.env, which validates that WEBUI_SECRET_KEY exists. Without it, Python crashes before Alembic can even connect to the database.

"No config file 'alembic.ini' found"​

Cause: You're in the wrong directory.

Solution:

Terminal
# Find your container name if not 'open-webui'
docker ps

# Find alembic.ini location
find /app -name "alembic.ini" 2>/dev/null  # Docker
find . -name "alembic.ini"  # Local

# Navigate to that directory
cd /app/backend/open_webui  # Most common path

# Verify you're in the right place
ls -la alembic.ini

"Target database is not up to date"​

Cause: Your database version doesn't match expected schema.

Diagnosis:

Terminal - Diagnose Version Mismatch
# Check what database thinks its version is
alembic current

# Check what code expects
alembic heads

# Compare

Solution depends on diagnosis:

Scenario: alembic current shows older version than alembic heads

Fix: You simply need to apply pending migrations.

Terminal
alembic upgrade head
Never Use "alembic stamp" as a Fix

You may see advice to run alembic stamp head to "fix" version mismatches. This is dangerous.

alembic stamp tells Alembic "pretend this migration was applied" without actually running it. This creates permanent database corruption where Alembic thinks your schema is up-to-date when it isn't.

Only use alembic stamp <revision> if:

  • You manually created all tables using create_all() and need to mark them as migrated
  • You're a developer initializing a fresh database that matches current schema
  • You imported a database backup from another system and need to mark it at the correct revision
  • You've manually applied migrations via raw SQL and need to update the version tracking

Never use it to "fix" migration errors or skip failed migrations.

Process Hangs After "Will assume non-transactional DDL"​

Understanding the message: This is not an error. It's informational. SQLite doesn't support transactional DDL, so Alembic is warning that migrations can't be rolled back automatically.

If genuinely stuck:

Some migrations (especially those adding indexes or modifying large tables) take several minutes.

Action: Wait 3-5 minutes before assuming it's stuck.

Autogenerate Detects Removed Tables​

Symptom: You ran alembic revision --autogenerate and it wants to drop existing tables.

Don't Run Autogenerate

Regular users should NEVER run alembic revision --autogenerate. This command is for developers creating new migration files, not for applying existing migrations.

The command you want is alembic upgrade head (no revision, no --autogenerate).

If you accidentally created a bad migration file:

Terminal - Remove Bad Migration
# List migration files
ls -la /app/backend/open_webui/migrations/versions/

# Delete the incorrect auto-generated file (newest file)
rm /app/backend/open_webui/migrations/versions/<newest_timestamp>_*.py

# Restore to known good state
git checkout /app/backend/open_webui/migrations/  # If using git

Technical context: The "autogenerate detects removed tables" issue occurs because Open WebUI's Alembic metadata configuration doesn't import all model definitions. This causes autogenerate to compare against incomplete metadata, thinking tables should be removed. This is a developer-level issue that doesn't affect users running alembic upgrade.

Peewee to Alembic Transition Issues​

Background: Older Open WebUI versions (pre-0.4.x) used Peewee migrations. Current versions use Alembic.

Symptoms:

  • Both migratehistory and alembic_version tables exist
  • Errors about "migration already applied"

What happens automatically:

  1. Open WebUI's internal/db.py runs old Peewee migrations first via handle_peewee_migration()
  2. Then config.py runs Alembic migrations via run_migrations()
  3. Both systems should work transparently

If automatic transition fails:

Terminal - Manual Transition
# Check if old Peewee migrations exist
sqlite3 /app/backend/data/webui.db "SELECT * FROM migratehistory;" 2>/dev/null

# If Peewee migrations exist, ensure they completed
# Then run Alembic migrations
cd /app/backend/open_webui
alembic upgrade head
tip

If upgrading from very old Open WebUI versions (< 0.3.x), consider a fresh install with data export/import rather than attempting to migrate the database schema across multiple major version changes.

PostgreSQL Foreign Key Errors​

PostgreSQL Only

This troubleshooting applies only to PostgreSQL databases. SQLite handles foreign keys differently.

Symptom: Errors like psycopg2.errors.InvalidForeignKey: there is no unique constraint matching given keys for referenced table "user"

Cause: PostgreSQL requires explicit primary key constraints that were missing in older schema versions.

Solution for PostgreSQL:

PostgreSQL Fix
-- Connect to your PostgreSQL database
psql -h localhost -U your_user -d open_webui_db

-- Add missing primary key constraint (PostgreSQL syntax)
ALTER TABLE public."user" ADD CONSTRAINT user_pk PRIMARY KEY (id);

-- Verify constraint was added
\d+ public."user"

Note: The public. schema prefix and quoted "user" identifier are PostgreSQL-specific. This SQL will not work on SQLite or MySQL.

Advanced Operations​

Production and Multi-Server Deployments​

Rolling Updates Can Cause Failures

In multi-server deployments, running different code versions simultaneously during rolling updates can cause errors if the new code expects schema changes that haven't been applied yet, or if old code is incompatible with new schema.

Recommended deployment strategies:

Run migrations as a one-time job before deploying new application code:

Kubernetes Job Example
# 1. Run migration job
kubectl apply -f migration-job.yaml

# 2. Wait for completion
kubectl wait --for=condition=complete job/openwebui-migration

# 3. Deploy new application version
kubectl rollout restart deployment/openwebui

This ensures schema is updated before any new code runs.

Generate SQL Without Applying​

For review or audit purposes, generate the SQL that would be executed:

Terminal - Generate Migration SQL
# Generate SQL for pending migrations
alembic upgrade head --sql > /tmp/migration-plan.sql

# Review what would be applied
cat /tmp/migration-plan.sql

Use cases:

  • DBA review in enterprise environments
  • Understanding what changes will occur
  • Debugging migration issues
  • Applying migrations in restricted environments
When to Use This

This is advanced functionality for DBAs or DevOps engineers. Regular users should just run alembic upgrade head directly.

Offline Migration (No Network)​

If your database server is offline or isolated:

Terminal - Offline Migration Workflow
# 1. Generate SQL on development machine
alembic upgrade head --sql > upgrade-to-head.sql

# 2. Transfer SQL file to production
scp upgrade-to-head.sql production-server:/tmp/

# 3. On production, apply SQL manually
sqlite3 /app/backend/data/webui.db < /tmp/upgrade-to-head.sql

# 4. Update alembic_version table manually
sqlite3 /app/backend/data/webui.db \
  "UPDATE alembic_version SET version_num='<target_revision>';"
Manual alembic_version Updates

Only update alembic_version if you've actually applied the corresponding migrations. Lying to Alembic about migration state causes permanent corruption.

Recovery Procedures​

Recovery from Failed Migration​

SQLite Has No Rollback

SQLite migrations are non-transactional. If a migration fails halfway through, your database is in a partially-migrated state. The only safe recovery is restoring from backup.

Symptoms of partial migration:

  • Some tables exist, others don't match expected schema
  • Foreign key violations
  • Missing columns that migration should have added
  • Application errors about missing database fields

Recovery steps:

Terminal - Restore from Backup
# 1. Stop Open WebUI immediately
docker stop open-webui

# 2. Verify backup integrity
sqlite3 /path/to/webui.db.backup "PRAGMA integrity_check;"

# 3. Restore backup
cp /path/to/webui.db.backup /path/to/webui.db

# 4. Investigate root cause before retrying
docker logs open-webui > migration-failure-logs.txt

# 5. Get help with logs before attempting migration again
Do Not Use "stamp" to Fix Failed Migrations

Never use alembic stamp to mark a partially-failed migration as complete. This leaves your database in a corrupt state.

Validate Database Integrity​

Before and after migrations, verify your database isn't corrupted:

Terminal - SQLite Integrity Check
sqlite3 /app/backend/data/webui.db "PRAGMA integrity_check;"

# Should output: ok
# If it outputs anything else, database is corrupted

Post-Migration Checklist​

After successful migration, verify:

  • alembic current shows (head) indicating latest version
  • Open WebUI starts without errors
  • Can log in successfully
  • Core features work (chat, model selection, etc.)
  • No error messages in logs
  • Data appears intact (users, chats, models)
  • Backup can be safely archived after 1 week of stability
Keep Recent Backups

Retain backups from before major migrations for at least 1-2 weeks. Issues sometimes appear days later during specific workflows.

Getting Help​

If migrations continue to fail after following this guide:

Gather diagnostic information:

Terminal - Collect Diagnostic Data
# Version information
docker logs open-webui 2>&1 | head -20 > diagnostics.txt

# Migration state
cd /app/backend/open_webui
alembic current -v >> diagnostics.txt
alembic history >> diagnostics.txt

# Database info (SQLite)
sqlite3 /app/backend/data/webui.db ".tables" >> diagnostics.txt
sqlite3 /app/backend/data/webui.db "SELECT * FROM alembic_version;" >> diagnostics.txt

# Full migration log
alembic upgrade head 2>&1 >> diagnostics.txt

Where to get help:

  1. Open WebUI GitHub Issues: https://github.com/open-webui/open-webui/issues

    • Search existing issues first
    • Include your diagnostics.txt file
    • Specify your Open WebUI version and installation method

  2. Open WebUI Discord Community

    • Real-time support from community members
    • Share error messages and diagnostics

  3. Provide this information:

    • Open WebUI version
    • Installation method (Docker/local)
    • Database type (SQLite/PostgreSQL)
    • Output of alembic current and alembic history
    • Complete error messages
    • What you were doing when it failed
note

Do not share your webui.db database file publicly - it contains user credentials and sensitive data. Only share the diagnostic text output.