Electric Postgres Security

This skill builds on electric-proxy-auth. Read it first for proxy security patterns.

Electric — Postgres Security Checklist

Run through each section before deploying Electric to production.

User Permission Checks

Check: Electric user has REPLICATION role

Expected:

SELECT rolreplication FROM pg_roles WHERE rolname = 'electric_user';
-- Should return: true

Fail condition: rolreplication = false or user does not exist. Fix: ALTER ROLE electric_user WITH REPLICATION;

Check: Electric user has SELECT on synced tables

Expected:

SELECT has_table_privilege('electric_user', 'todos', 'SELECT');
-- Should return: true

Fail condition: Returns false. Fix: GRANT SELECT ON todos TO electric_user; or GRANT SELECT ON ALL TABLES IN SCHEMA public TO electric_user;

Check: Electric user has CREATE on database

Expected:

SELECT has_database_privilege('electric_user', current_database(), 'CREATE');
-- Should return: true (unless using manual publishing mode)

Fail condition: Returns false and not using ELECTRIC_MANUAL_TABLE_PUBLISHING=true. Fix: GRANT CREATE ON DATABASE mydb TO electric_user;

Table Configuration Checks

Check: REPLICA IDENTITY FULL on all synced tables

Expected:

SELECT relname, relreplident
FROM pg_class
WHERE relname IN ('todos', 'users')
  AND relreplident = 'f';  -- 'f' = FULL

Fail condition: relreplident is 'd' (default) or 'n' (nothing). Fix: ALTER TABLE todos REPLICA IDENTITY FULL;

Check: Tables are in the Electric publication

Expected:

SELECT tablename FROM pg_publication_tables
WHERE pubname = 'electric_publication_default';

Fail condition: Synced tables missing from the list. Fix (manual mode): ALTER PUBLICATION electric_publication_default ADD TABLE todos;

Connection Checks

Check: DATABASE_URL uses direct connection (not pooler)

Expected:

DATABASE_URL=postgres://user:pass@db-host:5432/mydb

Fail condition: URL points to a connection pooler (e.g., PgBouncer on port 6432, Supabase pooler). Fix: Use direct Postgres connection for DATABASE_URL. Set ELECTRIC_POOLED_DATABASE_URL separately for pooled queries.

Check: wal_level is set to logical

Expected:

SHOW wal_level;
-- Should return: logical

Fail condition: Returns replica or minimal. Fix: Set wal_level = logical in postgresql.conf and restart Postgres.

Common Security Mistakes

CRITICAL Using connection pooler for DATABASE_URL

Wrong:

DATABASE_URL=postgres://user:pass@pooler.example.com:6432/mydb

Correct:

DATABASE_URL=postgres://user:pass@db.example.com:5432/mydb
ELECTRIC_POOLED_DATABASE_URL=postgres://user:pass@pooler.example.com:6432/mydb

Connection poolers (except PgBouncer 1.23+) do not support logical replication. Electric must connect directly to Postgres for its replication slot.

Source: website/docs/guides/deployment.md:91

HIGH Missing REPLICA IDENTITY FULL on tables

Wrong:

CREATE TABLE todos (id UUID PRIMARY KEY, text TEXT);
-- Replica identity defaults to 'default' (PK only)

Correct:

CREATE TABLE todos (id UUID PRIMARY KEY, text TEXT);
ALTER TABLE todos REPLICA IDENTITY FULL;

Without REPLICA IDENTITY FULL, Electric cannot stream the full row on updates and deletes. Updates may be missing non-PK columns.

Source: website/docs/guides/troubleshooting.md:373

HIGH Electric user without REPLICATION role

Wrong:

CREATE USER electric_user WITH PASSWORD 'secret';

Correct:

CREATE USER electric_user WITH PASSWORD 'secret' REPLICATION;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO electric_user;

Electric uses logical replication and requires the REPLICATION role on the database user.

Source: website/docs/guides/postgres-permissions.md

Pre-Deploy Summary

• Electric user has REPLICATION role
• Electric user has SELECT on all synced tables
• Electric user has CREATE on database (or manual publishing configured)
• All synced tables have REPLICA IDENTITY FULL
• All synced tables are in the Electric publication
• DATABASE_URL uses direct Postgres connection (not pooler)
• wal_level = logical in Postgres config
• ELECTRIC_SECRET is set (not using ELECTRIC_INSECURE=true)
• Secrets are injected server-side only (never in client bundle)

See also: electric-proxy-auth/SKILL.md — Proxy injects secrets that Postgres security enforces. See also: electric-deployment/SKILL.md — Deployment requires correct Postgres configuration.

Version

Targets Electric sync service v1.x.