PgSqlCaller is a small, focused wrapper for running raw SQL against PostgreSQL through ActiveRecord. It exposes a stable, documented API on an ActiveRecord-backed class you name, covering the queries the query builder makes awkward: single-scalar and single-column SELECTs, raw rows, ActiveRecord::Result reads, and type-cast (serialized) variants that decode PostgreSQL arrays and custom column types into Ruby objects. Every ? placeholder is bound and escaped through the ActiveRecord sanitizer, so statements stay injection-safe with no manual quoting. On top of that it adds PostgreSQL-specific helpers — non-consuming sequence peeking, table and relation sizes, EXPLAIN ANALYZE, NOTICE capture, and quoting/sanitizing utilities — plus a fast, injection-safe bulk update that partially updates many existing rows in a single UPDATE ... FROM unnest(...) statement and round-trip. The reader API is extensible via define_sql_method, and the gem runs on Ruby 3.2+ with Rails 7.1 through 8.1.