Programming Languages Used in open-seo: A Complete Technical Breakdown

open-seo relies primarily on TypeScript and TSX for its full-stack architecture, while leveraging JavaScript, SQL, YAML, and Docker for supporting infrastructure and tooling.

The every-app/open-seo repository is a modern SEO management platform that demonstrates how a unified TypeScript codebase can power both React frontends and server-side logic. Understanding the programming languages used in open-seo reveals a strategic blend of core application code and configuration languages optimized for developer experience and deployment flexibility.

TypeScript and TSX: The Core Language Stack

TypeScript dominates the open-seo codebase, serving as the primary programming language for the React user interface, TanStack router configurations, and server-side functions. The project uses TSX (TypeScript with JSX) extensively for component development, enabling type-safe JSX syntax throughout the application.

The router configuration in src/router.tsx demonstrates this pattern:

// src/router.tsx
import { createRouter as createTanStackRouter } from "@tanstack/react-router";
import { routeTree } from "./routeTree.gen";
import { DefaultCatchBoundary } from "./client/components/DefaultCatchBoundary";
import { NotFound } from "./client/components/NotFound";

export function getRouter() {
  const router = createTanStackRouter({
    routeTree,
    defaultPreload: "intent",
    defaultErrorComponent: DefaultCatchBoundary,
    defaultNotFoundComponent: () => <NotFound />,
    scrollRestoration: true,
  });

  return router;
}

This file illustrates how TypeScript interfaces with the TanStack ecosystem. Additional configuration files like web/vite.config.ts and drizzle.config.ts further confirm TypeScript's role in build tooling and ORM setup, managing both SQLite and Postgres database adapters through type-safe configurations.

Supporting Languages and Infrastructure Configuration

While TypeScript handles application logic, open-seo incorporates several auxiliary languages for specific operational needs.

JavaScript for Utility Scripts

Plain JavaScript appears in Node.js utility scripts and release tooling that execute outside the main TypeScript compilation pipeline. The repository includes files like scripts/release-notes.mjs and compiled CLI authentication helpers that handle auxiliary tasks such as data seeding and release automation.

SQL for Database Migrations

Raw SQL powers the database schema definitions and migration scripts managed by the Drizzle ORM. Migration files located in directories like drizzle-pg/ contain platform-specific SQL for Postgres deployments:

-- drizzle-pg/0012_dashboard.sql
CREATE TABLE dashboard (
  id          SERIAL PRIMARY KEY,
  user_id     INTEGER NOT NULL,
  created_at  TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at  TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

These SQL files execute during deployment to establish table structures, indexes, and relationships outside the TypeScript type system.

YAML for DevOps and Workspace Management

YAML configures the project's monorepo structure and deployment orchestration. The pnpm-workspace.yaml file defines the workspace layout for the pnpm package manager, while compose.yaml handles Docker Compose orchestration for local development environments.

Dockerfile and Containerization

The Dockerfile.selfhost uses Dockerfile syntax to define container images for self-hosting scenarios, specifying base images, dependency installation, and runtime configurations necessary for containerized deployment.

JSON and Markdown for Metadata and Documentation

JSON and JSONC (JSON with Comments) appear in package.json manifests and configuration files like wrangler.jsonc, while Markdown documents the project structure in README.md and other specification files.

Summary

• TypeScript/TSX serves as the dominant programming language for open-seo's React frontend, TanStack router, and server-side functions.
• JavaScript handles utility scripts and Node.js tooling executed outside the main application build.
• SQL defines database schemas and migrations for Postgres and SQLite through Drizzle ORM.
• YAML manages monorepo workspaces and container orchestration configurations.
• Dockerfile, JSON, and Markdown provide container definitions, package manifests, and project documentation respectively.

Frequently Asked Questions

Is open-seo written entirely in TypeScript?

No, while TypeScript is the primary programming language for application logic in the every-app/open-seo repository, the project incorporates JavaScript for utility scripts, SQL for database migrations, YAML for configuration, and Dockerfiles for containerization. The main application code in src/router.tsx and configuration files like drizzle.config.ts are TypeScript, but supporting infrastructure uses additional languages.

What database does open-seo use?

According to the source code analysis, open-seo supports both SQLite and Postgres databases, configured through the Drizzle ORM. The presence of drizzle-pg/0012_dashboard.sql and similar migration files indicates Postgres support, while the drizzle.config.ts file configures adapters for multiple database engines.

Why does open-seo use YAML files?

The repository uses YAML for project-level configuration that requires human-readable structure without the strict syntax of JSON. Files like pnpm-workspace.yaml define the monorepo workspace layout for pnpm, while compose.yaml manages Docker Compose services, making dependency and service management more maintainable than equivalent JSON configurations.

Can I contribute to open-seo if I only know JavaScript?

Yes, though TypeScript is preferred for core contributions, plain JavaScript skills remain valuable for utility scripts located in the scripts/ directory and for understanding compiled outputs. However, modifying the React components in src/router.tsx or server functions requires TypeScript familiarity to maintain type safety across the full-stack architecture.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}