Disc Documentation

Disc is a schema-first, TypeScript-native database built on Deno. It sits on top of PostgreSQL and provides a declarative schema language (SDL), a purpose-built query language (EdgeQL), automatic migrations, and a bundled PostgreSQL instance that requires zero manual setup. Disc is a fork of Gel (formerly EdgeDB), reimplemented in TypeScript while preserving EdgeQL and SDL.

Quick Links

I want to…	Go to
Get up and running from scratch	Getting Started
Define types, links, and constraints	Schema (SDL)
Write queries and mutations	EdgeQL
Look up built-in functions	Functions Reference
Use the CLI	CLI Reference
Manage schema changes over time	Migrations
Generate a typed client (TS/Rust/Go)	Codegen
Use the TypeScript SDK in my app	Client SDK
Write filter queries against schemas	Filter API
Configure the Disc server	Server Configuration
Set up authentication	Auth
Add row-level security	Access Policies
Use extensions	Extensions
Browse data in a web UI	Admin UI
Understand the bundled PostgreSQL	Bundled PostgreSQL
Deploy to production	Production Deployment
Deploy on Kubernetes with Helm	Production Deployment → Kubernetes (Helm)
Send auth emails over SMTP	Auth → Email Delivery (SMTP)
Drive Disc from a Deno script	CLI → Programmatic API
Tune queries, indexes, and caches	Performance
Run Disc via Docker Compose	Docker Compose
Run and write tests	Testing
Cut and publish a release	Releasing

Key Concepts

Schema-first. Your data model is defined in .disc files using SDL (Schema Definition Language). Disc parses these definitions, generates migrations, creates PostgreSQL tables, and produces TypeScript types -- all from one source of truth.

EdgeQL. Disc uses EdgeQL, not SQL, as its primary query language. EdgeQL compiles to PostgreSQL SQL under the hood but provides a cleaner syntax for nested data, filtering, and type-safe queries. You never write raw SQL unless you want to.

Bundled PostgreSQL. Running disc init downloads and manages a PostgreSQL instance automatically. Users never install, configure, or maintain PostgreSQL directly. For production, an external PostgreSQL can be connected via --backend-dsn.

TypeScript-native. The entire stack -- schema parser, query compiler, migration engine, server, CLI, and SDK -- is written in TypeScript and runs on Deno. No Python, Rust, or Java dependencies at runtime. (Your application need not be TypeScript: disc codegen also emits Rust and Go clients that speak the same HTTP API.)

Full Table of Contents

Getting Started -- Install Deno, create a project, write a schema, run queries, generate types.
Schema (SDL) -- Object types, scalar types, links, properties, constraints, defaults, computed fields, abstract types, modules.
EdgeQL -- SELECT, INSERT, UPDATE, DELETE, shapes, filters, ordering, pagination, aggregation, subqueries, parameters.
EdgeQL Cheat Sheet -- One-page reference of common EdgeQL forms.
Functions Reference -- Built-in scalar functions, aggregate functions, date/time functions, string functions, math functions.
CLI Reference -- All CLI commands, flags, and usage examples, plus the programmatic CLI.* API for scripting Disc from Deno.
Migrations -- Creating, applying, rolling back, and squashing migrations. Schema diffing and DDL generation.
Codegen -- Generating interfaces, query builders, and client code from your schema, in TypeScript, Rust, or Go.
Client SDK -- Using the DiscClient to run queries, manage transactions, subscribe to changes, and handle authentication.
Filter API -- Object-shaped filter queries on the generated client: operators, combinators, link traversal (single, multi-hop, multi-link, junction tables), shape narrowing, ordering, pagination.
Server Configuration -- Environment variables, ports, connection pools, CORS, WebSockets, logging, and protocol options.
Auth -- JWT-based authentication, user registration, login, session management, email delivery over SMTP, and the AuthManager SDK.
Access Policies -- Object-level access policies in SDL, row-level security enforcement, auth context bridging.
Extensions -- Built-in extensions and the extension system architecture.
Admin UI -- Schema browser, data viewer, query editor, REPL, and migration history in the web-based admin interface.
Bundled PostgreSQL -- How Disc downloads, initializes, and manages PostgreSQL. Instance lifecycle, version upgrades, socket configuration.
Production Deployment -- TLS, connection pools, health checks, rate limiting, Docker, native binaries, systemd, Kubernetes via Helm, monitoring.
Performance -- Indexing strategy, EXPLAIN diagnostics, parse/compile/EXPLAIN caches, pool tuning, key Prometheus gauges, the deno bench suite.
Docker Compose -- Self-hosted Disc + bundled PostgreSQL via docker compose up.
Testing -- Running the suite, test categories, authoring new tests, env isolation, PG-backed tests.
REST API -- Schema-derived REST endpoints for every object type, plus the OpenAPI 3.1 spec at /api/openapi.json.
Error Codes -- The error hierarchy, protocol code map, and what each code means on the wire.
Disc-Original Features -- The deliberate departures from Gel that justify Disc as a fork rather than a port.
Releasing -- How releases are cut and published; the current version is tracked in version.txt.