ReJot
Feed
Updates, notes, and experiments. Longer items link through to the blog.
Follow @WilcoKr on XReceiving Resend inbound email without webhooks
An essay on how the Resend “fragment” turns inbound email into a threaded, database-backed integration, with the route mounting and persistence concerns packaged into the library.
Fragno: full-stack encapsulation
The new Fragno home page explains the core idea behind the project: packaging routes, reactive client hooks, and optional database schemas together as full-stack libraries.
Implicit last-write-wins behaviour in the age of agents
A short note on why implicit last-write-wins breaks down in more concurrent workflows, and why optimistic concurrency control is a better default when agents are in the loop.
A reminder about amortization (please pipeline your DB queries)
Argues for batching/pipelining as a middle ground between interactive transactions and CTE-heavy queries, reducing round trips while keeping procedural logic readable.
Fragno Changelog: Unified SqlAdapter, File Uploads, and Standard Schema Validation
Release highlights include the unified SqlAdapter, multipart file uploads, Standard Schema validation for table definitions, and zero-config SQLite for development.
Writing docs for humans and coding agents
Lessons from tasking a coding agent to use your docs: provide complete examples, make APIs unambiguous, and shorten feedback loops to catch hallucinations quickly.
A knowledge management system inspired by plain-text accounting
How plain-text accounting inspired Thalo, a structured plain-text knowledge system with validation, linking, and AI-friendly workflows.
Zod's fromJSONSchema
Looks at Zod 4.3’s fromJSONSchema() for serverless validation, compares it with Ajv and
@cfworker/json-schema, and explains why Fragno Forms moved to Zod.
FoundationDB's versionstamps should be everywhere
Explains versionstamps as a global ordering primitive for change feeds and concurrency control, and why other databases should expose an equivalent feature.
Thalo: A structured plain-text format for personal knowledge
Thalo is a plain-text format that gives your knowledge just enough structure for tools and AI to work with it, while staying readable and editable by humans. Just text files in git, editable in Cursor or by Claude Code.
Define entities, dump thoughts, let LLMs extract structured entries, and synthesize insights from your scattered notes. The CLI provides a feedback loop with schema validation and reference checking.
Check out the website and GitHub repository.
Fragno Changelog: Durable Hooks, Improved Cloudflare Support
Release highlights:
- Durable hooks for reliable post-transaction side effects.
- Improved Cloudflare Durable Objects support and migration helpers.
- Developer-experience upgrades across the database layer.
Fragno: Toolkit for building full-stack TypeScript libraries that embed into your users' applications
Fragno is a toolkit for building full-stack TypeScript libraries that work seamlessly across different frameworks such as Next.js and Nuxt. Fragno library users integrate in a couple lines of code. Write your API once, get type-safe clients for React, Vue, and vanilla JavaScript automatically.
Check out the documentation website.
Semcheck: Spec-Driven Development using LLMs
This post showcases Semcheck, a tool that uses LLMs to verify consistency between specifications and code as a pre-commit or CI step.
Concurrency in Call of Duty's VM, Compared to JavaScript
Call of Duty’s scripting language runs on a virtual machine with an interesting execution model. In this blog post, I’ll give a quick overview of the language’s core constructs and syntax, and then dive into how its execution model compares to JavaScript’s event loop.
Reliable Webhook Delivery on Cloudflare Workflows
Webhook delivery systems seem straightforward until you need guaranteed ordering. This one requirement increases the complexity of the system significantly, which makes it an interesting case for evaluating an infrastructure platform.
In this blog post I’ll walk through the design and implementation of a reliable webhook delivery system on Cloudflare Workflows.
What would an AI assistant look like that can be integrated into any app?
This is a small prototype for an integrated chat experience that hooks into React Router (or Remix). Context is automatically filled with the actions the user is taken. The LLM will use tool calls to load information from any route.
Experimenting with adding Cursor-like features to a map view. In this example I turn swyx’s guide to Singapore into a map easily. Turns out LLMs are fairly good at geocoding.
When Kafka is not the right Move
A short walk through a chess example that shows how event streams can force consumers to reconstruct state and business logic that producers already have.
The Burdens of Data
An essay on treating data as a product, publishing stable data interfaces, and preferring synchronization over imperative fetching inside larger organizations.