Hi Effecters!
Welcome back to This Week In Effect (TWIE) - your weekly update of the latest developments in the Effect community and ecosystem.
Effect is a powerful TypeScript library that helps developers create 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 as well as our guide for installing Effect. Enjoy!
Recent major updates:
- Effect Days 2025: Effective Pragmatism and Next-gen DevTools for Effect.
- Build and run durable workflows in TypeScript with
@effect/workflow. - The Effect community on Discord reached 4360+ members!
Technology
-
Effect LSP v. 0.20.1 has been released!
This @EffectTS_ LSP update is for your Rpc & Cluster lovers! - Rpc.make will autocompletion with class syntax! - Go to definition in RpcClient will resolve to Rpc definition ...plus other nitpicks, more info over: github.com/Effect-TS/lang…
-
Tim Smart released effect-mcp, an MCP server that adds tools and resources for accessing Effect documentation.
MCP server for adding the effect ref docs to your ide: github.com/tim-smart/effe… Also written with @EffectTS_ of course!
Here are all the technical changes from the past week.
Effect Core
- Minor updates to Record.findFirst (Optimization)
- Ensure ‘proto’ as name argument in do notation is preserved on lexical scope (Bug Fix)
- Add missing type variances in Match.ValueMatcher (Bug Fix)
- Fix Context.add Context.make fns (Bug Fix)
- Ensure DateTime.make interprets strings without zone as UTC (Bug Fix)
- Schedule output has been added into CurrentIterationMetadata (Feature, next-minor)
Effect AI
- Disallow excess options in AiLanguageModel methods (Bug Fix)
- Introduce a native McpServer implementation for Effect (Feature)
- Add .of helpers to RpcGroup, Entity and AiToolkit (Feature)
- Eliminate McpServer requirement from resource layers (Optimization)
- Remove McpServer requirement from McpServer.resource (Optimization)
- Allow undefined mcp payloads (Improvement)
Effect Cluster
- Fix ShardManager metrics (Bug Fix)
- Add more spans to ClusterWorkflowEngine (Improvement)
- Add disableFatalDefects option to cluster entities (Feature)
- Add .of helpers to RpcGroup, Entity and AiToolkit (Feature)
Effect Platform
- Allow property signatures in HttpApiSchema.param (Improvement)
Effect RPC
- Rpc error middleware & ping timeouts (Bug Fix)
- Add disableFatalDefects option to cluster entities (Feature)
- Add spanAttributes option to RpcServer constructors (Improvement)
- Add jsonrpc serialization to rpc (Feature)
- Add .of helpers to RpcGroup, Entity and AiToolkit (Feature)
Effect Workflow
- Remove Workflow.Registration type (Bug Fix)
- Prevent shadowing of Workflow context (Bug Fix)
- Add disableFatalDefects option to cluster entities (Feature)
Effect Days 2025 Updates
This week, we published Attila Večerek and Mattia Manzati’s talks.
Attila Večerek explored what software quality really means, highlighting the importance of balancing quality, costs, and technology choices for successful software delivery.
In this post-conf interview, Attila shares what he loves about Effect, how he got into it, and his hopes for the future.
At Effect Days 2025, we caught up with Attila Večerek (@attilavecerek), Senior Staff Engineer at Zendesk, to hear what he loves about Effect, how he got into it, and what he hopes for the future!
Mattia Manzati talked about developer tooling for Effect. Since this talk, new features have been added to the Effect LSP, such as:
- Effect types while hovering yield*
- Autocomplete .gen, .fn and Data.Class
- quickinfo why services got required/provided
- Warn on multiple package versions
- goto definition for Rpc clients
Community Highlights
-
Exciting news! Glide is using Effect in production.
Started shipping @EffectTS_ in production this quarter and now @glideapps is growing faster than ever. Cannot be a coincidence.
-
The 14.ai team is hosting an Effect sushi dinner on Wednesday, 18 June in San Francisco, where they’ll talk about Building Agentic Systems with Effect! Sign up to join them!
-
Dillon Mulroy livestreamed three episodes of his new series Implementing RFC-1035 (DNS) with EffectTS 🚀 on his Twitch channel.
Effect Content Update
-
Maxwell Brown and Tim Smart were live on X(Twitter) and Twitch on Wednesday with a new episode of Building an Effect-native MCP Server.
Building an Effect-Native MCP Server x.com/i/broadcasts/1…
-
Maxwell livestreamed his new series, Building an Effect AI Provider Integration for Google.
Building an Effect AI Provider Integration for Google x.com/i/broadcasts/1…
Cause & Effect Podcast
Don’t forget to listen to our Cause & Effect podcast hosted by Johannes Schickling and available on Youtube, X(Twitter), and audio platforms like Spotify and Apple Podcast.
This podcast highlights stories from software engineers and companies using Effect in production. Each episode explores their journey of adopting Effect, including the learning process, challenges faced, and benefits of integrating Effect into their tech stack.
We’ve published our second episode with Michael Fester from Markprompt about scaling AI-powered customer support with Effect, building reliable and high-performance infrastructure, and enhancing developer productivity in a fast-evolving AI landscape. Let us know your thoughts on our social media or Discord!
Effect Job Opportunities
More and more companies are adopting Effect in their projects. Here’s a list of companies looking for software engineers with Effect experience:
-
Expand.ai: Founding Engineer
-
Platonic Systems: Remote Effect Engineers
-
Medbill.ai: Founding Software Engineers (full-stack and backend)
-
Oneiro Solutions: Software Engineer - Core Team. Join Effect Discord and DM leighman for further info.
-
Microsub: TS Developer
-
Samsung Food: Full Stack Developer
-
Margins: Product Engineer
-
Precurion looking for a remote‑first Founding Engineer with Effect experience. The job posting is available in the
#job-boardchannel on our Discord. -
Vitalize is hiring a full-stack engineer with Effect experience: Senior Full-Stack Engineer
-
Embedded Insurance is hiring for a Senior Software Engineering position.
-
Betalyra, an AI consulting company from Portugal, is looking for a part-time freelance software engineer (Typescript/Effect) with AI experience. The job posting is available in the
#job-boardchannel on our Discord. -
Software Intelligence Works: Senior Full-Stack Engineer
-
14.ai: Founding engineer
-
Wander is hiring Software Developers with experience in Effect.
-
Stealth team looking for a software engineer with Effect experience. The job posting is available in the
#job-boardchannel on our Discord. -
A French-speaking startup team led by Stephan Le Dorze is looking for a freelancer to join them - see his LinkedIn post for more details.
-
Freckle.io, is hiring Platform Engineers with experience in Effect.
-
A stealth team that has already scaled their product to 50K daily active users in the last year, is looking for Effect Developers. DM wireless on X for more info.
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
In December 2024, we unveiled the Effect Merch Store with a selection of Effect-branded items designed for the community. All orders are processed through Printful.
Effect Merch is here! We’re excited to announce the launch of our Effect merch page! Grab your favorite swag & show your love for Effect in style! 🧢 effect.website/merch
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