# Stack

I write most code with AI agents. I plan the work, set the rules and review every change before it merges.

## How I work with agents

- **Frontier models:** Claude Fable 5.1 and Opus 5.5, GPT-6 Astra and Sol, Gemini 3.1 Pro and 3.8 Flash, Grok 4.7.
- **Skills:** I wrote more than 70 open-source skills that teach agents to use each library correctly and follow the code patterns I want in a codebase.
- **Guardrails:** Strict types, lint rules and tests run on every change.
- **Parallel work:** Subagents run research, implementation and review in parallel.
- **Human review:** I read every diff before it merges.

## Language and runtime

- **TypeScript:** My main language, with strict mode on.
- **Bun:** Runtime, package manager, test runner and bundler.
- **Node.js:** When a platform or client requires it.
- **Effect:** Typed errors, services and concurrency. I publish Effect v4 libraries.
- **Zod:** Schemas for validation and types.

## Frontend

- **React 19:** Server and client components, actions, Suspense.
- **TanStack Start:** Full-stack React with type-safe server functions.
- **TanStack Router:** Typed routes, params and search state.
- **TanStack Query:** Server state, caching and optimistic updates.
- **TanStack Form:** Typed forms with schema validation.
- **Next.js 16:** App Router, server actions, ISR and caching.
- **Base UI:** Accessible unstyled components.
- **shadcn/ui:** Component source I copy into the project.
- **Tailwind CSS 4:** Design tokens and utility styling.
- **Motion:** UI animation.
- **Tiptap:** Rich text and document editors.
- **TanStack Table:** Headless data grids with sorting, filters and paging.
- **D3 and visx:** Custom charts.
- **Storybook:** Component development and review.

## Backend

- **Elysia:** Bun-native HTTP with end-to-end types.
- **oRPC:** Typed RPC that also speaks OpenAPI.
- **Better Auth:** Sessions, OAuth, organizations and 2FA.
- **Drizzle ORM:** Schema, queries and migrations.
- **PostgreSQL:** My default database.
- **Redis:** Cache, sessions, rate limits and queues.
- **BullMQ:** Background jobs with retries and schedules.
- **Trigger.dev:** Long-running jobs and workflows.
- **React Email:** Transactional email built as components.
- **ClickHouse:** Analytics on large event tables.
- **Kafka:** Event streams between services.

## AI in products

- **Vercel AI SDK:** Streaming, tool calls and structured output across providers.
- **Agents and MCP:** Tool-calling agents and MCP servers.
- **OpenAPI to MCP:** cabrakan, my CLI that creates an MCP server from an OpenAPI spec.
- **Model mix:** OpenAI, Anthropic, Google, xAI, Mistral, DeepSeek, Llama and Groq.
- **ElevenLabs:** Voice generation and voice agents.

## Infrastructure

- **Cloudflare Workers:** APIs and proxies at the edge. KV, D1, R2.
- **Vercel:** Frontend hosting and previews.
- **Railway:** Services, databases and templates.
- **Wrangler:** Deploys and local dev for Workers.
- **Docker:** Builds and local services.
- **AWS S3:** Object storage.
- **Upstash:** Serverless Redis for caching and rate limits.
- **Vite:** Dev server and builds.

## Quality and insight

- **Sentry:** Error tracking and traces.
- **PostHog:** Product analytics, funnels and flags.
- **Oxlint and Oxfmt:** Linting and formatting, with my own rules in bellona.
- **Vitest:** Unit and integration tests.
- **Playwright:** End-to-end browser tests.
- **Testcontainers:** Integration tests against Postgres and Redis in Docker.

## Content and CMS

- **anhur:** My tool that turns content files into typed data.
- **MDX and Markdown:** Docs, blogs and changelogs next to the code.
- **Ghost:** Blogs and publications. I maintain a Railway template for it.
- **Strapi and Directus:** Headless CMS for client content teams.

## Open-source packages

- **tsdown:** Builds for npm libraries.
- **publint:** Checks package.json before release.
- **Are the types wrong:** Checks type exports for ESM and CJS.
- **Turborepo:** Monorepos for packages and apps.

## Agent tools

- **Claude Code:** Terminal agent for multi-file work and long tasks.
- **OpenAI Codex:** Coding agent on GPT-6 models.
- **Cursor:** Editor with agents and frontier models.
- **GitHub Copilot:** Inline help and PR work.
- **OpenCode:** Open-source terminal agent.
- **Devin:** Long background tasks.
- **CodeRabbit:** Automated review on every pull request.
- **v0:** UI drafts.
- **Warp:** Terminal with built-in agents.