Hi Effecters!
Welcome back to This Week In Effect, your weekly update of the latest developments in the Effect community and ecosystem.
Effect is the TypeScript library for the AI era, helping developers build complex, synchronous, and asynchronous programs. One key feature that sets Effect apart is how it leverages structured concurrency to provide features such as async cancellation and safe resource management, making it easier to build robust, scalable, and efficient programs.
To get started, below you’ll find links to our documentation and our guide for installing Effect. Enjoy!
Recent major updates:
Technology #
Effect LSP rules are now available as custom, type-aware OXLint rules. We now also support vite-plus.
Effect’s API reference docs, for both v3 and v4, are now available on the website.
Effect v4 Beta updates
The v4 beta had a focused week, with Schema refinements, MCP improvements, SQL fixes, and continued HTTP and AI work. The team also conducted a deep audit of the entire Effect codebase, systematically reviewing and fixing edge cases across all modules to ensure correctness and reliability ahead of the upcoming RC release.
Schema: Renamed Schema error constructors for consistency, fixed deduplication of JSON Schema fallback definitions, and resolved representation identifiers by AST identity.
MCP: Fixed MCP conformance issues and added a test suite, and emitted MCP tool output schemas.
SQL: Added D1 batch support, ran SQL persistence cleanup in bounded batches to avoid lock contention, and fixed TMap.remove
/removeAll
clearing entire buckets on hash collision.
HTTP & tracing: Added HttpClient
tracer header filter for fine-grained control over which headers are included in traces, and propagated trace context for persisted workflow requests.
AI: Fixed OpenAI stable web search action parameters.
CLI & docs: Added Doc.sanitize
for stripping unsafe content from CLI output, and fixed KeyValueStore
file backend docs.
Workflow: Propagated trace context across persisted workflow request boundaries.
You can follow the full changelog in the [effect repository](https://github.com/Effect-TS/effect/commits/main).
To catch up on more updates, check out [Effect v4 Beta updates](https://effect.website/blog/tags/effect-v4-beta-recaps/).
General Chores
Cause & Effect Podcast | Episode #10 #
Software Engineering in the Age of AI
John A. De Goes joins Johannes Schickling and Michael Arnaldi to discuss how AI is reshaping software engineering, what developers should still learn, and why Effect’s primitives are especially valuable for coding agents.
John is the creator of [ZIO](https://zio.dev/), as well as CEO of [Ziverge](https://www.ziverge.com/) and [Golem Cloud](https://golem.cloud/).
[ Play ](https://youtube.com/watch?v=irmz5X3c7Do)
The Cause & Effect podcast, hosted by Johannes Schickling, features stories from software engineers and companies that use Effect in production and is available on YouTube, X(Twitter), and audio platforms like Spotify and Apple Podcast.
Effect Adoption Partner #
Save your seat for the first Effect Training Workshop by John De Goes! Meanwhile, enjoy a conversation between John De Goes and Michael Arnaldi on Why TypeScript is a Good Fit for Unemployed Scala Developers.
One of the many reasons to use Effect!
Many such stories! 😉
💯
“Brain, summarize this website” (cit. Kit Langton)
Foldocs - a framework for building documentation websites with Foldkit and Effect. By TarkaWorks.
Effect Team Content Update #
- Effect TSGO, Oxlint, and Type-Aware Rules for Effect | Effect Office Hours 40 🔥
- Stop the agent slop with Effect | Maxwell Brown
- Testing LLM workflows with Effect at OpenCode | Kit Langton
Effect Job Opportunities #
Looking for a role where you can work with Effect? We now have a dedicated Effect jobs page with open roles from companies using Effect.
New this week: Medblocks is hiring a Full Stack Developer in Bangalore, India. Satispay is hiring a Frontend Software Engineer in Milan, Italy.
Disclaimer: Please note that these job postings are shared for informational purposes, and we encourage applicants to verify details directly with the hiring companies.
Effect Merch Store #
The Effect Merch Store offers a selection of Effect-branded items designed for the community. All orders are processed and fully managed through Printful.
Closing Notes #
That’s all for this week. Thank you for being a vital part of our community. Your feedback is highly valued as we fine-tune this format. Feel free to share your thoughts, and we’ll do our best to tailor it to the needs of our community.
Effect Community Team