Gel (formerly EdgeDB) Patterns

Quick Guide: Gel (formerly EdgeDB) is a graph-relational database built on PostgreSQL. Define schemas in .gel files using SDL with types, links, and computed properties. Use gel migration create + gel migrate for schema changes. Query with EdgeQL (set-based, deeply nested shapes) or the TypeScript query builder (e.select, e.insert). Everything in EdgeQL is a set -- empty sets need explicit casts, and operations on sets produce Cartesian products. Use global variables with access policies for row-level security. The query builder requires a running database for code generation (npx @gel/generate edgeql-js).

Naming: EdgeDB was rebranded to Gel in February 2025. The edgedb npm package, CLI, and .esdl extension still work via compatibility shims, but new projects should use gel, @gel/generate, and .gel files.

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CRITICAL: Before Using This Skill

All code must follow project conventions in CLAUDE.md (kebab-case, named exports, import ordering, import type, named constants)

(You MUST run npx @gel/generate edgeql-js after every gel migrate -- the generated query builder is based on the database schema and becomes stale after migrations)

(You MUST cast empty sets explicitly (<str>{}, <int64>{}) -- bare {} is a syntax error because EdgeQL is strongly typed and cannot infer the type of an empty set)

(You MUST understand that all EdgeQL values are sets -- operations on multi-valued expressions produce Cartesian products, not element-wise results)