Awesome Effect

Libraries, tools, apps, and learning material for Effect, the TypeScript library for typed errors, dependency injection, concurrency, and streams.

Effect 4 is the current major. The list is split by it: Effect v4 core is what ships with Effect 4, Ecosystem libraries are third-party packages that work next to it, and Effect v3 legacy holds the packages that were merged into core plus libraries still pinned to effect@3. Tools, apps, examples, and learning resources follow.

More

• Applications and examples - Open source apps built on Effect, plus templates and starters.
• Learning Effect - Courses, patterns, articles, talks, and podcasts.
• Community and adoption - Meetups, official channels, and companies using Effect.

Contents

• Effect v4 core
  • Links
  • Core packages
  • Official tooling and repos
• Ecosystem libraries
  • State management and UI
  • Framework integrations
  • HTTP, RPC, and API
  • OpenAPI and code generation
  • Schema, data types, and utilities
  • Databases and storage
  • Local-first and sync
  • Messaging, jobs, workflows, and actors
  • Cloud and infrastructure
  • AI, agents, and MCP
  • Agent skills and rules
  • Testing
  • Logging, tracing, and observability
  • CLI and terminal
  • Service SDKs and API clients
  • Authentication and authorization
  • Blockchain
• Effect v3 legacy
  • Packages merged into Effect v4
  • Libraries for Effect v3
• Development tools
  • Editors and language service
  • Linting and code style
  • Scaffolding and migration
  • Playgrounds and visualizers
• Effect in other languages
• Other lists

Effect v4 core

Links

• Documentation (v4) - Docs for the Effect 4 release candidate.
• Documentation (v3) - Docs for Effect 3.
• API reference (v4) - Generated API docs for Effect 4.
• API reference (v3) - Generated API docs for Effect 3.
• Blog - Release notes, recaps, and announcements.
• Effect 4 release candidate announcement - August 2026 post that tagged the first RC and asked for a veto before 4.0 ships. Monthly recaps follow under Effect v4 updates.
• This Week in Effect - Weekly newsletter with releases, community projects, and events. Most entries in this list were first announced there.
• Community hub - Meetup calendar, social links, and event submission form.
• Effect jobs - Job board for roles that use Effect.
• Adoption partners - Consultancies that help teams adopt Effect.
• Myths about Effect - Official page answering common objections.
• Effect-TS/effect - The monorepo. The main branch is Effect 4.
• Merch store - Effect-branded items.

Core packages

Published from the Effect-TS/effect monorepo at the shared v4 version. Packages that only exist for Effect 3 are under Effect v3 legacy.

• effect - The core library: Effect, Layer, Schema, Stream, Config, Metric, Cache, and more. In v4 it also holds what used to be separate packages under effect/unstable/*: ai, cli, cluster, devtools, eventlog, http, httpapi, jsonschema, observability, persistence, process, reactivity, rpc, schema, socket, sql, workflow, and workers.
• @effect/platform-node - Node.js implementations of the platform interfaces.
• @effect/platform-bun - Bun implementations of the platform interfaces.
• @effect/platform-browser - Browser implementations of the platform interfaces.
• @effect/platform-deno - Deno implementations of the platform interfaces.
• @effect/sql-pg - PostgreSQL driver.
• @effect/sql-pglite - PGlite driver for PostgreSQL in WebAssembly.
• @effect/sql-mysql2 - MySQL driver.
• @effect/sql-mssql - Microsoft SQL Server driver.
• @effect/sql-clickhouse - ClickHouse driver.
• @effect/sql-libsql - libSQL and Turso driver.
• @effect/sql-d1 - Cloudflare D1 driver.
• @effect/sql-sqlite-node - SQLite driver for Node.js.
• @effect/sql-sqlite-bun - SQLite driver for Bun.
• @effect/sql-sqlite-wasm - SQLite driver for browsers via WebAssembly.
• @effect/sql-sqlite-react-native - SQLite driver for React Native.
• @effect/sql-sqlite-do - SQLite driver for Cloudflare Durable Objects.
• @effect/ai-openai - OpenAI provider.
• @effect/ai-anthropic - Anthropic provider.
• @effect/ai-openrouter - OpenRouter provider.
• @effect/ai-openai-compat - Provider for OpenAI-compatible APIs.
• @effect/atom-react - React bindings for the Atom reactive state module. The v3 predecessor is @effect-atom/atom-react, listed under Effect v3 legacy.
• @effect/atom-solid - SolidJS bindings for Atom.
• @effect/atom-vue - Vue bindings for Atom.
• @effect/opentelemetry - Export Effect spans, metrics, and logs through OpenTelemetry.
• @effect/vitest - it.effect, it.live, it.scoped, and TestClock helpers for Vitest.
• @effect/openapi-generator - Generate Schema types, HTTP clients, and HttpApi modules from OpenAPI specs.
• @effect/language-service - TypeScript language service plugin with Effect-specific diagnostics, quick fixes, and refactors.
• @effect/tsgo - TypeScript-Go build with the Effect language service compiled in. Includes an LSP-based linter.
• @effect/eslint-plugin - ESLint rules for Effect projects, such as dprint formatting and no-import-from-barrel.
• @effect/docgen - Documentation generator that type-checks the examples in JSDoc.
• @effect/build-utils - Build scripts used to package Effect libraries.

Official tooling and repos

• Effect-TS/effect-smol - Where Effect 4 was developed before it moved to the main repo. Kept for history.
• Effect-TS/docgen - Source for @effect/docgen.
• Effect-TS/build-utils - Source for @effect/build-utils.
• Effect-TS/website - Source for effect.website, built with Astro.
• Effect-TS/discord-bot - The community Discord bot, written with Effect.
• Effect-TS/wa-sqlite - Fork of wa-sqlite used by @effect/sql-sqlite-wasm. Last updated 2025.
• Effect-TS/next-release-action - GitHub Action for staged release branches from changesets.

Ecosystem libraries

Third-party libraries that work next to Effect 4. An entry ending in publishes an effect peer range that accepts 4.x. No tag means the range is open-ended or the project publishes none; check before you depend on it.

State management and UI

• sproott/effect-atom-svelte - Svelte bindings for Effect Atom.
• jarrednorrisdev/effect-atom-svelte - Svelte 5 bindings for Effect Atom, published as effect-atom-svelte, with async atoms you can await in markup, server rendering with hydration, and atoms for RPC and HttpApi.
• nhattran998/tanstack-db-atom - Atoms that wrap TanStack DB collections and queries.
• typeonce-dev/effect-xstate - XState actor integration for Effect Atom.
• foldkit/foldkit - Frontend framework built on Effect with the Elm Architecture (one Model, a Message union, a pure update, and Commands that wrap Effects), plus routing, accessible UI components, server rendering, and a DevTools MCP server for coding agents. Site.
• elianiva/foldcn - shadcn/ui components ported to Foldkit.
• bjacobso/foldworks - Themeable components, a data grid, and a form builder for Foldkit, styled with StyleX.
• doeixd/foldkit-plus - Exposes a Foldkit app's Model and an allow-list of its Messages to agents through WebMCP, MCP, and A2A, plus forms, CRUD, sync, and server rendering packages.
• Aniket-508/foldocs - Documentation site framework built on Foldkit.
• stefvw93/weft - Reactive DOM library where every node is an Effect.
• pigoz/effect-lsc - Server-owned UI in the style of Phoenix LiveView: components run on the server as Effects, JSX describes the page, and browser events travel over a WebSocket and come back as DOM updates.
• ilhajs/ilha - Isomorphic UI library that renders components on the server and hydrates only the interactive islands in the browser, with atoms for reactivity.
• craft-ts/craft-ts - Signal-first toolkit for state, async work, services, forms, dependency injection, and routes, with an @craft-ts/effect adapter that exposes Effect programs as reactive resources. Guide for Effect users.
• m9tdev/verrex - UI framework where the A, E, R channels of an Effect survive from every leaf of the view tree to the root.
• doeixd/effect-atom-jsx - Fine-grained JSX runtime with Layer-provided services, async atoms, and optimistic actions.
• lself1022/effer - UI library built on lit-html with Effect at the core.
• Thiladev/effect-view - Write React function components as Effects.
• bmvantunes/effect-view-server - Turns validated source streams into typed snapshots and deltas for React and other clients.
• frondruntime/frond - Frontend runtime for React and MobX-facing application state.
• Inalegwu/EffectCanvas - Canvas renderer for React driven by Effect.
• timurrakhimzhan/unitflow - Effect-first state manager.
• Handfish/effstate - Actor-based state management built on Effect.
• zaymonoid/katha - State management with saga-pattern side effects on Effect's structured concurrency.
• run4w4y/effect-state-tree - Experimental state tree with immutable snapshots and typed commits for Effect and Schema.
• typeonce-dev/effect-machine - Schema-first state machines and statecharts. Home of the proposed Machine API while it incubates.
• cevr/effect-machine - Schema-first state machines with compile-time transition checks, state-scoped effects, and persistence.
• umpire-tools/umpire - Reactive derived state for forms with interdependent options.
• carloitaben/conform-to-effect - Conform helpers that validate forms with Effect Schema.
• Alette Signal - Frontend data fetching library built with Effect.
• julia-script/effect-motion - Animation primitives on Effect.
• lucas-barake/effect-form - Forms with Effect Schema validation and React bindings.

Framework integrations

• voidhashcom/effect-query - TanStack Query adapter that works with Effect RPC and HttpApi clients.
• tiesen243/effect-tanstack-query - Bridge Effect HttpApi clients into TanStack Query options.
• EthanShoeDev/effect-tanstack-start - Serve Effect HttpApi from TanStack Start.
• artisanstreet/svelte-effect-runtime - Effect runtime for Svelte components.
• RATIU5/sveltekit-effect-runtime - Wrappers for running Effect in SvelteKit handlers, loaders, and actions.
• heddendorp/effect-angular - Angular adapters for Effect Platform HttpClient and Effect RPC.
• glitchkids/press.gk - Git-based CMS for Astro with an Effect runtime and Cloudflare deployment.
• honojs/middleware - Contains @hono/effect-validator, a Hono validator middleware for Effect Schema.
• daotl/fastify-type-provider-effect-schema - Effect Schema type provider for Fastify.
• tatemz/effect-htmx - Effect Platform, Bun, MVC, and HTMX.
• PatrickOgilvie/popcomputer-web - Full-stack framework for Cloudflare Workers: Hono routing, Inertia and React pages, Better Auth sign-in and Drizzle, with every handler an Effect program.
• austinm911/effect-zero - Effect-backed server adapters for Zero sync mutators. Supports Effect v3 and v4.
• realms-labs/effect-zero - Another Effect integration for Zero mutators.
• osuki-dev/vite-plugin-effect - Vite plugin exposing a backend API and RPC gateway as a virtual client module.
• effect-app/libs - Application libraries from effect-app, covering API contracts, client, and Vue integration.
• effect-native/effect-native - Native platform tools built on Effect: cr-sqlite service, OpenRouter client, and schemas. Effect v4 packages published under @beta.
• rockware-ai/nx - Nx plugins that scaffold Effect libraries, services, and Node apps with @effect/vitest.
• nounder/effect-start - Declarative full-stack apps with Effect.

HTTP, RPC, and API

• utopyin/effect-orpc - Effect integration for oRPC.
• TheDevMinerTV/typed-at-rest - Typesafe HTTP handlers and clients backed by Effect Schema.
• mac-monet/effect-domain - Single source of truth for an API, derived into servers and clients.
• @thomasfosterau/effect-jsonapi - Define and implement JSON:API-compliant APIs.
• gabeins/effect-jsonapi - JSON:API spec support for Effect.
• Dr-Nikson/effect-grpc - gRPC and Protobuf for Effect.
• erikshestopal/effect-protobuf - Generate Effect Schemas from .proto files and encode or decode binary, ProtoJSON, and text formats.
• modevol-com/gqloom - GraphQL schema and resolvers from runtime types, with an Effect Schema adapter.
• egriff38/effect-graphql - Prototype code-first GraphQL on Effect Schema and RPC.
• anomalyco/effect-http-recorder - Record Effect HTTP and WebSocket traffic once, replay from JSON cassettes in tests.
• joepjoosten/odata-effect - Tree-shakable OData V2 and V4 client for SAP services with code generation.
• successkrisz/effect-packages - effect-lambda AWS Lambda wrappers and effect-oauth-client, an OAuth 2.0 client credentials helper for the v4 HttpClient.
• tim-smart/multipasta - Cross-platform multipart parser used by @effect/platform.
• bastikohn/effect-grpc - gRPC with a protoc plugin that generates Effect services.

OpenAPI and code generation

• tim-smart/openapi-gen - Generate Effect HTTP clients from OpenAPI specs.
• lucas-barake/openapi-gen - Generate Effect Schema types and HttpClient implementations from OpenAPI specs.
• jbt95/openapi-effect - Generate Effect Schema and HTTP clients from OpenAPI 3.0 and 3.1.
• astahmer/typed-openapi - Headless TypeScript API client generator with Effect Schema output.
• orval-labs/orval - OpenAPI client generator with an @orval/effect target.
• daotl/ts-to-effect-schema - Generate Effect Schemas from TypeScript types and interfaces.
• use-drzl/drzl - Drizzle codegen with @drzl/generator-effect and @drzl/generator-effect-http targets.
• Michael4d45/effect-schema-generator - Effect Schema generator.

Schema, data types, and utilities

• joepjoosten/effect-avro - Five @effect-avro packages for Avro schemas and binary data.
• PaulJPhilp/effect-json - Schema-driven JSON serialization.
• effect-yaml - YAML utilities from the Effect 2 era.
• osbytes/standard-schema-faker - Seeded fake data for Standard Schema validators, Effect Schema included.
• saiashirwad/effect-grammar - Effect Schema, but for text formats.
• tvshevchuk/effect-schema-geojson - Schemas for GeoJSON types.
• leonitousconforti/effect-schemas - Shared schemas used across the author's projects.
• arckit-dev/effect - Schema utilities for domain modeling with branded types.
• just-be-dev/effect-typed-id - TypeID spec implementation.
• rjdellecese/effect-units - Typed quantities and unit conversions checked by the type system.
• parischap/effect-libs - Date and number parsing and formatting, sscanf and sprintf templating, pretty printing, and ANSI styles.
• overengineeringstudio/effect-utils - Utilities and integrations collected from the author's production apps.
• spencerbeggs/effected - Git, commands, and YAML services, the app plumbing Effect leaves to you.
• ayronforge/haversack - Typed services for email, analytics, feature flags, payments, auth, and blob storage.
• nunofyobiz/effect-extras - Convenience wrappers and data structures that fill gaps in core modules.
• ggallovalle/effext - Extensions exploring what belongs in the standard library.
• jacob-ebey/mini-effect - Minimal lazy, composable, cancellable effect system, not compatible with Effect.
• typesugar/typesugar - Compile-time macros for TypeScript with an Effect package.
• nikelborm/effect-garden - Monorepo of small Effect packages and an oxlint import plugin.
• systemfsoftware/systemfsoftware - Effect libraries and developer tooling for functional software architecture, spanning v3 and v4.
• dataquail/effect-server-utils - Utility libraries for Effect servers.

Databases and storage

• drizzle-team/drizzle-orm - Drizzle added an @effect/sql-pg driver with an async design for Effect.
• relsunkaev/effect-qb - Typed SQL query builder that renders per dialect and executes through Effect SQL.
• gloomweaver/effql - Code generation in the style of sqlc for Effect SQL, driven by PostgreSQL introspection.
• eikster-dk/sqlc-gen-better-typescript - Plugin for sqlc that emits Effect v4 or plain async code from SQL queries.
• m9tdev/effect-prisma-generator - Prisma generator that emits an Effect service wrapper with typed errors and transactions. Supports Effect v3 and v4.
• Cyberistic/Prisma-Effect-Schema-Generator - Prisma generator that emits an Effect Schema per model. Supports Effect v3 and v4.
• jmenga/effect-dynamodb - DynamoDB ORM with schema and geo packages.
• evryg-org/effect-contrib - Neo4j client, schema, and Vitest helpers from Evryg.
• jellologic/starrocks-sdk - StarRocks SDK with Effect services, Stream Load, and a query builder.
• alphaiv-project/supabase-effect - Supabase JS client wrapper.
• fwal/effect-firebase - Firebase adapters for Effect.
• Cortex - Effect-native ORM for vector databases.
• Lucas-Bur/effect-memfs - Platform-agnostic in-memory file system.
• leonitousconforti/eftar - GNU ustar tar implementation on Effect streams.

Local-first and sync

• lucas-barake/effect-local - Local-first mutation log on Effect v4, Automerge, SQLite, and Effect RPC.
• evelant/synchrotron - Offline-first multiplayer sync for PostgreSQL with PGlite that converges without conflict resolution code.
• michaelshimeles/self-sync - Sync engine for SvelteKit with reactive IndexedDB state, WebSockets, and PostgreSQL or MySQL adapters.
• kevmodrome/tablinum - Local-first data layer backed by Nostr.
• humanlayer/effect-durable-streams - Durable Streams protocol server as a portable Effect v4 app with swappable platform Layers.

Messaging, jobs, workflows, and actors

• TeamWarp/effect-mq - Background jobs with schema-first definitions, a worker runtime, and a PostgreSQL store inside your Drizzle schema.
• TeamSpringbird/effect-temporal - Runs effect/unstable/workflow programs on Temporal: activities, durable timers, signals, updates, queryable state, schedules, and Nexus operations, with one workflowBundle shared by the worker and every client.
• erikshestopal/effect-inngest - Durable workflows with Inngest, Effect-native steps, and Layer injection.
• fdarian/effect-hatchet - Hatchet bindings with an in-memory implementation for tests.
• tim-smart/effect-genserver - GenServer-style actors that work with cluster, RPC, or Atom.
• cevr/effect-encore - Declarative actors and durable workflows for @effect/cluster.
• crosshatch/liminal - Effect, actors, and Cloudflare.
• rivetkit/effect - Effect SDK for Rivet actors.
• golemcloud/effect-golem - Author durable Golem agents with
• CodeForBreakfast/eventsourcing - Event sourcing library on Effect, with bun-test-effect and ESLint packages in the same repo.
• Mufraggi/effect-workflow-viz - Remix dashboard for visualizing @effect/workflow runs.

Cloud and infrastructure

• alchemy-run/alchemy - Infrastructure as code written as Effect programs.
• alchemy-run/distilled - Effect-native SDKs for cloud providers generated from Smithy and OpenAPI models. Includes distilled-aws and @distilled.cloud/cloudflare, a typed Cloudflare SDK for R2, KV, Workers, Queues, Workflows, and DNS.
• kondaurovDev/effortless-aws - Code-first serverless framework that derives AWS infrastructure from handlers.
• danieljvdm/effect-cf - Primitives for Cloudflare Workers and bindings.
• jbt95/effect-cf - Typed clients for Cloudflare Workers with schema validation.
• nr1brolyfan/effectful-cloudflare - Interact with Cloudflare resources.
• aryasaatvik/effect-platform-cloudflare - Run an Effect HTTP router as a Cloudflare Worker.
• backpine/effect-worker - Cloudflare Worker with request-scoped database connections via HttpApiMiddleware.
• acoyfellow/lab - Sandboxed isolates on Cloudflare Workers with typed capabilities.
• jonbeckman/cf-container-orchestrator - Orchestrate Cloudflare Containers with replica sets and restart policies.
• siebix-studio/effect-reusables - Cloudflare Browser Run and Resend services.
• entropitor/terraform-providers - Write Terraform providers in TypeScript with Effect. Blog post.
• leonitousconforti/the-moby-effect - Moby and Docker API client.
• leonitousconforti/the-wireguard-effect - Cross-platform WireGuard client on wireguard-go.
• leonitousconforti/efffrida - Compatibility layers between Frida's JavaScript API and Effect packages.
• flux-control-solutions/Effect-modbus-rs - Modbus communication over Rust napi bindings.
• triargos/effect-hcloud - Hetzner Cloud client.

AI, agents, and MCP

• betalyra/effect-uai - Building blocks for agentic AI with provider packages. Effect v4. Docs.
• humanlayer/fold - Provider-agnostic, isomorphic agent core with an optional coding agent, CLI, and TUI.
• doeixd/affe-agent - Agent execution kernel: sessions, runs, turns, steering, and typed lifecycle events.
• danieljvdm/effect-agent - Agent engine package.
• mpsuesser/effect-autoagent - Define agents as declarative blueprints and run them as Effect services.
• clavia-labs/tardigrade - Framework for durable, modular agents.
• semantiv-ai/effectful - LLM task pipelines compiled to Effect programs.
• saiashirwad/roop - Coding agent runtime built on Effect.
• lvndry/jazz - CLI for creating autonomous agents with real-world capabilities.
• betalyra/cuttlekit - Generative UI toolkit that streams LLM-built interfaces into a sandbox.
• kitlangton/rune - Give an agent one confined TypeScript-shaped code tool instead of a tool catalog.
• acoyfellow/effect-agents - Five example agents on Effect v4 with one local and one Cloudflare entrypoint. Site.
• mpsuesser/effect-claudecode - Write Claude Code plugins with Effect v4: hooks, skills, settings, and MCP servers.
• k3dom/pi-plugins - Single-purpose plugins for the pi agent harness built on Effect.
• egriff38/effect-herdr - SDK for the herdr terminal agent multiplexer.
• gjermundgaraba/effect-actions - Define an action once with Schema and serve it over HTTP and MCP, as an AI Toolkit, and from a CLI.
• tim-smart/effect-mcp - MCP server that gives agents Effect documentation search. Published as effect-mcp and as a Docker image.
• niklaserik/effect-mcp - Another MCP server for fetching Effect docs.
• cipher-rc5/firecrawl-mcp-effect - Self-hostable Firecrawl MCP server.
• seanwessmith/bun-mcp - MCP server for Bun documentation.
• dearlordylord/huly-mcp - MCP server and CLI for the Huly platform.
• glassBead-tc/audius-mcp-atris - Code Mode MCP server for the Audius music platform.
• yovanoc/effect-cdp - Chrome DevTools Protocol client on @effect/platform with streaming.
• LordCoughmann/effect-libs-browser - Browser automation for Workers and edge runtimes with Playwright, Stagehand, and CDP packages.
• acoyfellow/ralphwiggums - Prompt-driven browser automation on Cloudflare Workers.
• acoyfellow/unsurf - Turn any website into a typed API.
• millionco/expect - Lets agents test your code in a real browser.
• erayack/effect-gpt - Transformer LLM built from scratch with Effect, covering tokenization, training, and inference.
• mikearnaldi/effect-torch - Experimental tensor library with a Rust backend on candle, by the Effect author.
• lloydrichards/edu_effect-rag-builder - RAG prototype with ChromaDB.
• Kastalien-Research/mcp-effect-sdk - MCP SDK for the 2025-07-28 spec written with Effect.

Agent skills and rules

• Effect-TS/skills - Official skills for skill-aware coding agents, including the effect-v3-to-v4 migration skill.
• kitlangton/skills - Kit Langton's local Effect skill. Pairs with Effect Solutions in learning.md.
• joelhooks/effectts-skills - Effect v4 skill covering services, layers, schemas, errors, testing, HTTP, CLI, and config.
• betalyra/effect-skills - Opinionated best-practice guidelines for Effect codebases.
• mrevanzak/effect-ts-skills - Skills compatible with skills.sh.
• artimath/effect-skills - Skills for AI coding agents.
• teeverc/effect-ts - Skills for Effect v3 and v4.
• pekochan069/effect-skills - Skills for Effect.
• andrueandersoncs/claude-skill-effect-ts - Claude Code plugin with skills, commands, and agents.
• ivanacostarubio/effect-ts - Claude Code skill for Effect.
• adamthewilliam/promptbuddy-agent-skills - Skills for Expo, Effect, and Bun.
• Effect best practices on skills.sh - Skill by Makisuo.
• dojofoo/dojofoo - Coding practices and courses with an Effect package.
• mpsuesser/pi-effect-harness - Extension for pi that enforces Effect v4 practices during agent sessions.
• mpsuesser/opencode-effect-enforcer - OpenCode plugin with 44 regex and AST rules that block Effect anti-patterns in real time.
• doeixd/opencode-ralph-rlm - OpenCode plugin for Ralph outer-loop development, built on Effect.
• iskandarsulaili/hermes-ultimate-coding - Hermes agent plugins including Effect guidance.
• directormac/effect-v4-docs - Effect v4 docs packaged for agents.
• 1045290202/effect-ts-doc-skill - Effect v3 docs as a Chinese-language knowledge base skill.
• FOSSforlife/effect-guides - Personal Claude-written guides for Effect.
• dtechvision/great-repo-files - Files to add to Bun and Effect projects.
• The one weird git trick that makes coding agents more Effect-ive - Official guide to giving agents the Effect source.

Testing

• tatemz/effect-bdd - Runner for Gherkin .feature files.
• cevr/effect-bun-test - Test helpers for bun test.
• wezter96/spana - End-to-end testing across React Native and web from one test suite.
• middle-ages/effect-ts-laws - Property-based law tests for type class instances.
• Effect-TS/effect - @effect/doctest runs the examples in JSDoc as tests.
• Jobflow-io/effect-playwright - Playwright as Effect services and layers for browser automation and scraping.

Logging, tracing, and observability

• getsentry/sentry-javascript - @sentry/effect reports Effect errors and spans to Sentry. Supports Effect v3 and v4.
• MapleTechLabs/maple - OpenTelemetry observability platform with @maple-dev/effect-sdk. Runs locally as a single binary.
• Necmttn/livetrace - Stream Effect spans from any backend to React UIs.
• DanielFGray/effect-devtui - Terminal UI for Effect DevTools: traces, spans, and metrics.
• jagreehal/effect-analyzer - Static analysis that extracts structure, computes complexity, and draws diagrams from Effect code.
• cevr/effect-wide-event - One structured event per request.
• just-be-dev/evlog-effect - Effect bindings for evlog.
• atrim-ai/effect-span-tree-demo - Visualize deeply nested traces with path tracking.
• Lensflare - macOS development observability stack for humans and agents.

CLI and terminal

• lloydrichards/effect-boxes - Layout system for terminal UIs with Flex, Container, and Grid combinators. Effect v4. Docs.
• stromseng/effective-progress - Progress bar for CLIs.
• sogoiii/effect-streamdown-terminal - Streaming markdown renderer for terminals.
• wolfcola/treeshake-check - Tree-shakeability analyzer built on @effect/cli.
• davidnussio/envsec - Secrets manager backed by native OS credential stores.
• ccntrq/git-jira-branch - Manage git branches for Jira tickets.

Service SDKs and API clients

• sue27/effect-slack - Slack SDK with retries and observability.
• tim-smart/dfx - Discord library with gateway, REST, and interactions.
• kondaurovDev/tg-bot-sdk - Telegram Bot API types and client.
• tobimori/effect-attio - Attio REST API on Effect's HttpClient.
• mpsuesser/effect-prodigi - Prodigi print-on-demand API.
• zuub-don/tutela - Unofficial SDK for Guardian Connect insurance APIs.
• mannyc2/nyc-transit-kit - NYC and MTA transit data APIs on Bun.
• opsydyn/postcodesio-effect-client - Client for postcodes.io.
• triargos/sdks - Procurat client. Supports Effect v3 and v4.
• tvsudhir2/edlink-effect-sdk - Edlink SDK.

Authentication and authorization

• alex-golubev/better-auth-effect-adapter - Better Auth database adapter for @effect/sql.
• leonitousconforti/effect-oidc - OIDC provider primitives, JWT and JWKS, and HttpApi resource-server middleware.
• nr1brolyfan/effect-auth-poc - Authentication toolkit proof of concept.
• just-be-dev/gatehouse-effect - RBAC, ABAC, and ReBAC authorization, ported from gatehouse-ts.
• nmnmcc/ability - CASL-inspired permission checks.

Blockchain

• julia-script/evm-effect - Ethereum Virtual Machine implementation in TypeScript built for debuggability.
• crosshatch/crosshatch - x402 payments across EVM and Solana with stablecoins.
• PaulRBerg/prb-effect - Utilities for Web3, Next.js, and XState.
• xstelea/radix-web3.js - Radix wallet, gateway, and transaction packages with @radix-effects/sbor.

Effect v3 legacy

Kept because Effect 3 is still in use. Nothing here should be picked for a new Effect 4 project without checking for a v4 release first.

Packages merged into Effect v4

• @effect/platform - Runtime-agnostic HTTP client and server, file system, terminal, workers, and key-value store interfaces. In v4: effect/unstable/http, httpapi, socket, workers, and process.
• @effect/rpc - Schema-typed RPC over HTTP, WebSocket, or workers. In v4: effect/unstable/rpc.
• @effect/cluster - Entities, sharding, and messaging across processes. In v4: effect/unstable/cluster.
• @effect/workflow - Durable workflows on top of cluster. In v4: effect/unstable/workflow.
• @effect/cli - Command-line parsing, subcommands, prompts, and help generation. In v4: effect/unstable/cli.
• @effect/printer - Pretty-printer for documents, with @effect/printer-ansi for terminal colors.
• @effect/sql - SQL client, migrations, and schema-typed queries. In v4: effect/unstable/sql.
• @effect/sql-drizzle - Run Drizzle queries through @effect/sql. Effect v3 only. Drizzle itself now ships an @effect/sql-pg driver, listed under Databases and storage.
• @effect/sql-kysely - Run Kysely queries through @effect/sql.
• @effect/ai - Provider-agnostic language model, tool calling, and embeddings API. In v4: effect/unstable/ai.
• @effect/ai-google - Google Gemini provider.
• @effect/ai-amazon-bedrock - Amazon Bedrock provider.
• @effect/typeclass - Functor, Monad, Semigroup, and other type classes.
• @effect/experimental - Modules under trial before they move to core, such as DevTools, event logs, and persistence. In v4: effect/unstable/devtools, eventlog, and persistence.
• tim-smart/effect-atom - Reactive state for Effect v3, published as @effect-atom/atom with React, Solid, Vue, and LiveStore bindings. In v4 the same design ships in core as @effect/atom-*.

Libraries for Effect v3

Peer dependency stops at 3.x, or no commits since before the Effect 4 release candidates.

State management and UI

• ericc-ch/effect-atom-solid - SolidJS bindings for effect-atom.
• TylorS/typed - Web application framework on Effect with push-based streams, routing, and templating. Last updated 2025.
• VasilVelikov00/effective-ui - Composable UI framework built on Effect. Last updated 2025.
• ToliaGuy/reffect - React bindings for Effect. Last updated 2025.
• 81reap/react-effect - Package for full-stack React and Effect applications. Last updated 2025.
• pkishorez/use-effect-ts - React hooks for running Effects. Last updated 2025.
• nemmtor/injectio - Turn React components into Effects that can return values, for modals and dialogs opened from code. Last updated 2025.
• savkelita/tea-effect - The Elm Architecture for TypeScript with Effect.
• derrickbeining/effect-mvu - Port of the Elm architecture to Effect. Last updated 2023.
• TylorS/typed-lazy-ref - Lazily evaluated, streaming state management. Last updated 2025.
• TylorS/typed-async-data - Loading, success, failure, and optimistic states for async data. Last updated 2025.
• TylorS/typed-navigation - Browser navigation on the Navigation API with a History API fallback. Last updated 2025.
• TylorS/typed-route - Type-safe, bidirectional route matching and interpolation on Effect Schema. Last updated 2025.
• hannoeru/formik-effect-schema - Effect Schema validation for Formik. Last updated 2024.
• SuttonKyle/effect-ts-react-stable-hooks - Port of fp-ts-react-stable-hooks to Effect. Last updated 2024.
• react-hook-form/resolvers - Includes an Effect Schema resolver for React Hook Form.
• stax-ui/stax - Reactive UI framework based on Effect primitives.

Framework integrations

• mcrovero/effect-nextjs - Typed helpers for Next.js App Router pages, layouts, server components, and actions.
• khanetor/effect-remix - Adapters for using Effect in Remix loaders and actions. Last updated 2024.
• JonahPlusPlus/solid-effect - Utilities for using Effect in SolidJS. Last updated 2024.
• devx-op/effectify - Monorepo of integrations: Solid bindings for effect-atom, Better Auth for Node, and more.
• withstudiocms/studiocms - Astro headless CMS whose @withstudiocms/effect package wraps Effect for Astro integrations.
• adamgoose/raycast-effect - Write Raycast extensions with Effect. Last updated 2025.
• mikearnaldi/vite-remix-effect - Remix on Vite with Effect, by the Effect author. Last updated 2023.
• mikearnaldi/effect-remix-stream - Streaming responses from Remix with Effect. Last updated 2024.
• Effect-Community/react - React integration with Query and Effect from the Effect 2 era. Last updated 2023.
• kuroski/effect-svelte - Run Effect programs in SvelteKit load and remote functions with error, redirect, and form handling.
• kylobyte-dev/keel - Fastify 5 backend framework with Effect Schema as type provider and controllers as Effect services.
• rjdellecese/confect - Convex with Effect: define schemas, validators, and functions as Effect services. Includes client bindings for Foldkit apps (@confect/foldkit).

HTTP, RPC, and API

• sukovanej/effect-http - Declarative HTTP APIs with OpenAPI generation. Predates HttpApi in @effect/platform, which covers the same ground. Last updated 2025.
• semyenov/effect-graphql - Type-safe GraphQL schemas and resolvers with Effect Schema.
• nrf110/effect-gql - Experimental GraphQL framework for Effect.
• pothos-plugin-effect - Pothos GraphQL plugin for resolvers that return Effects.
• Makisuo/effect-rpc-tanstack-devtools - TanStack Devtools panel for Effect RPC requests and timings. Last updated 2025.
• tim-smart/effect-http - Early HTTP toolkit that became @effect/platform. Last updated 2023.
• Sebastian-Prisacariu/effect-trpc - tRPC-style ergonomics for Effect apps. Experimental.
• adamjosefus/fx-fetch - Immutable, clonable HTTP fetching built on Effect.

OpenAPI and code generation

• fortanix/openapi-to-effect - Generate Effect Schema definitions from an OpenAPI document.
• davidgoli/effect-openapi-server-gen - Generate an HttpApi server from an OpenAPI schema. Last updated 2025.
• omar-dulaimi/supawatch - Compiles a PostgreSQL schema into validators, types, and API layers, with an Effect target.
• fasciajs/fascia - Describe a schema once, emit zod, arktype, effect, or valibot, and OpenAPI and JSON Schema.

Schema, data types, and utilities

• jessekelly881/effect-schema-compilers - Compile Effect Schemas to fakers, empty values, and semigroups. Last updated 2024.
• jessekelly881/effect-types - Schemas organized by data type. Last updated 2024.
• AMar4enko/effect-schema-compiler - Ergonomic compiler for Effect Schema ASTs.
• AMar4enko/effect-schema-avro - Avro codec for Effect Schema. Last updated 2025.
• jessekelly881/effect-yaml - YAML parsing helpers. Last updated 2024.
• srinitude/effect-json-schema - Effect Schema adapter for Standard JSON Schema V1.
• harrysolovay/standard-json-schema - Turn Standard Schema types, Effect Schema included, into JSON Schema. Last updated 2025.
• middle-ages/effect-schema-viz - Render Effect Schemas as Graphviz diagrams.
• dudeofawesome/effect-schemas - Common data schemas.
• TylorS/typed-id - UUID, NanoID, and ULID generation. Last updated 2025.
• TylorS/templeffect - Templating with Effect Schema parameter validation and nesting. Last updated 2025.
• PaulJPhilp/effect-mdx - Parse, compile, and manipulate MDX. Last updated 2025.
• PaulJPhilp/effect-regex - Regex processing CLI and library. Last updated 2025.
• PaulJPhilp/effect-env - Environment variables with schema validation. Last updated 2025.
• emergente-labs/effect-env - Environment variable configuration with Effect.
• hychen/effect-builder - Immutable builder pattern with runtime validation. Last updated 2024.
• sukovanej/effect-monocle - Port of monocle-ts optics. Effect v3, last updated 2024.
• middle-ages/effect-ts-folds - Recursion schemes for Effect.
• nipakke/effect-pantry - Add-ons for Node.js apps such as typed events.
• lishaduck/effect-utils - Small utilities for Effect. Last updated 2025.
• embedded-insurance/effect-use - Collection of Effect services. Last updated 2025.
• limwa/effect-bits - Utilities for working with Effect.
• konkerdotdev/effect-ts-prelude - Prelude re-exports. Effect v3, last updated 2024.
• jpb06/effect-errors - Pretty error reporting with source snippets and spans.
• btravstack/unthrown - Errors as values with a separate defect channel, with an Effect adapter.
• spion/effect-tagged-contextual-error - Tagged errors with context, inspired by Rust's anyhow. Last updated 2025.
• harrysolovay/toyffect - Toy re-implementation of Effect.gen and Context.Tag for learning how Effect works. Last updated 2025.
• clayroach/effect-sugar - For-comprehension style gen blocks via esbuild, tsc, and TS plugin transforms. Last updated 2025.
• ethanniser/effect-distributed-lock - Distributed semaphore with pluggable backends. In active development.

Databases and storage

• emergente-labs/effect-sql-model - Compile Effect Schema and @effect/sql model definitions into Drizzle tables.
• effect-sql-kysely - Kysely with @effect/sql, typed queries.
• Fredx87/effect-kysely - Kysely adapter. Last updated 2024.
• pigoz/effect-sql - Relational databases with Effect, from before @effect/sql. Last updated 2025.
• tim-smart/sqlfx - The SQL toolkit that became @effect/sql. Last updated 2024.
• samuelho-dev/prisma-effect-kysely - Generate Kysely-compatible Effect Schemas from Prisma models.
• jessekelly881/zenstack-effect - ZenStack plugin for Effect. Last updated 2025.
• akoenig/effect-sql-inline-migrations - Migration loader that does not read the file system.
• doubleloop-io/effect-mongodb - MongoDB toolkit with typed collections.
• Gialicus/effect-ts-mongodb - MongoDB driver wrapper. Last updated 2023.
• envoy1084/effect-redis - Redis bindings with transactions and pipelines.
• Vortex-Dimension-Digital/effect-redis-bun - KeyValueStore implementation on Bun's Redis client.
• effect-supabase - Supabase client wrapper.
• jys9962/effect-ts-typeorm - TypeORM integration. Last updated 2025.
• jessekelly881/effect-idb - IndexedDB wrapper. Last updated 2025.
• juemrami/effect-idb - IndexedDB wrapper with a transaction API.
• nounder/effect-memfs - In-memory file system for mocking and tests. Last updated 2025.
• 6qat/effect-redis - Effect wrapper for Redis.
• TylorS/effect-sql-kysely - @effect/sql interface for Kysely.
• al3xanderwalker/redfx - Redis with typed commands, schema-typed keys, pub/sub and streams as Effect Streams, and caching.
• jbt95/effect-kv - Cloudflare KV wrapper.
• jpb06/effect-cloudflare-r2-layer - Layer for Cloudflare R2 storage.

Local-first and sync

• dxos/dxos - Local-first platform and the Composer workspace app. Its ECHO database uses Effect Schema. Publishes @dxos/effect.
• typeonce-dev/sync-engine-web - Sync engine on React, Web Workers, Effect, and Loro.

Messaging, jobs, workflows, and actors

• spiko-tech/effect-messaging - Message broker toolkit with AMQP and NATS packages.
• floydspace/effect-kafka - Kafka producers and consumers. Docs. Last updated 2025.
• PaulJPhilp/effect-actor - Actor model on Effect. Last updated 2025.
• ReventlessDev/reventless-core - Event-sourced CQRS framework in ReScript with an Effect package.
• embedded-insurance/diachronic - Evolving durable programs on Temporal with Effect Schema. Last updated 2024.
• emre-yildiz-dev/effect-graph - Superstep graph engine with typed state, reducers, routing, and human-in-the-loop.
• sellooh/effect-cluster-via-sst - Effect Cluster deployed with the SST Cluster component. Last updated 2025.
• Effect-Deprecated/query - Request batching and caching from Effect 2, now built into core. Archived.
• tim-smart/cluster-docker - Effect Cluster running in Docker. Last updated 2025.

Cloud and infrastructure

• floydspace/aws-lambda-effect-runtime - Experimental custom Lambda runtime for Effect. Last updated 2025.
• pierskarsenbarg/effect-pulumi - Effect composability for Pulumi programs.
• fiws/effect-libreoffice - Convert documents through LibreOffice.
• Effect-Deprecated/process - Child process library ported from zio-process. Archived.
• floydspace/effect-aws - AWS SDK clients and a Lambda handler wrapped as Effect services. Effect v3. Docs.
• jpb06/effect-github-actions-layer - Layer for the GitHub Actions toolkit.
• jpb06/effect-octokit-layer - Layer for Octokit.
• kondaurovDev/aws-sdk - Generates an AWS SDK wrapper for Effect.

AI, agents, and MCP

• PaulJPhilp/EffectiveAgent - Application framework for concurrent AI agents. Last updated 2025.
• jambudipa/dynamic-flow - Generate complete LLM execution graphs at runtime. Last updated 2025.
• ai-task-runner-effect - Runner for named AI tasks with validator-agnostic codecs.
• hypen-space/gloop-effect - Typed, observable agent loops on gloop-loop.
• kpritam/cliq - CLI coding agent with multiple providers, written to show how coding agents work. Docs. Last updated 2025.
• claude-code-effect - SDK for the Claude Code CLI with typed generateText and generateObject.
• mannyc1/pi-agent-effect - Effect platform adapter for pi-agent-core.
• paoloricciuti/tmcp - Framework-agnostic MCP SDK with an @tmcp/adapter-effect schema adapter.
• glassBead-tc/effect-airtable-mcp - Airtable MCP server.
• grzegorz-bielski/extrospec - Toy RAG CLI on LlamaIndex. Last updated 2024.
• PaulJPhilp/effect-ai-cli - CLI for the @effect/ai package. Last updated 2025.
• PaulJPhilp/effect-supermemory - Supermemory client. Last updated 2025.
• tylerjrbuell/reactive-agents-ts - Composable LLM agent framework where the same code runs in every runtime.

Testing

• isthatcentered/testing-effect-ts-lightning-talk-examples - Code from an Effect Days 2025 lightning talk on testing. Last updated 2025.

Logging, tracing, and observability

• sukovanej/effect-log - Logger implementations. Effect v3, last updated 2024.
• rashedInt32/effect-logger-pretty - Colored console logger, silent in production. Last updated 2025.
• IMax153/effect-ts-logging - Logging with correlation and pluggable backends. Last updated 2023.
• observe-ts/observe-ts - Structural observability for Effect programs. Last updated 2025.
• jrkienle/posthog-effect - PostHog bindings.
• Effect-Deprecated/otel - OpenTelemetry from Effect 2, replaced by @effect/opentelemetry. Archived.

CLI and terminal

• PaulJPhilp/effect-cli-tui - Interactive prompts and display utilities on top of @effect/cli. Last updated 2025.
• Effect-TS/figlet - FIGlet font parser and renderer. Last updated 2024.

Service SDKs and API clients

• rubywwwilde/Teleffect - Telegram Bot API client. Last updated 2025.
• blissito/whatsapp-sdk - WhatsApp Business API SDK. Last updated 2025.
• PaulJPhilp/effect-notion - Proxy server for the Notion API. Last updated 2025.
• effect-stripe - Stripe wrapper.
• Malvolio/printify-effect - Printify print-on-demand API. Last updated 2025.
• betalyra/wordpress-effect - WordPress client.
• kevinmichaelchen/book-effect - Book metadata from Hardcover, Open Library, and Google Books. Last updated 2025.
• Kensei-Kimoto/kintone-effect-schema - Effect Schemas for kintone records. Last updated 2025.
• MateoKruk/effect-slack - Slack SDK.
• grom-dev/effect-tg - Telegram bot library.
• mmlngl/effect-messagekit - Toolkit for building and testing messaging app integrations.
• tim-smart/effect-obsidian - Write Obsidian plugins with Effect. Last updated 2025.

Authentication and authorization

• betalyra/sorry-dave - Authorization library. Last updated 2025.

Blockchain

• evmts/voltaire - Ethereum primitives with a voltaire-effect package for typed contract calls.
• HeliosLang/effect - Effect version of the Helios off-chain library for Cardano.

Development tools

Editors and language service

• Effect-TS/language-service - TypeScript plugin with diagnostics for missing errors in yield*, unused layers, and more. Works in any editor that uses tsserver.
• Effect-TS/tsgo - TypeScript-Go build with the Effect language service and an LSP-based linter.
• Effect-TS/vscode-extension - VS Code extension with a DevTools panel for traces, metrics, and fiber inspection. Marketplace.
• RATIU5/zed-effect-tsgo - Zed extension for @effect/tsgo. Zed extension page.
• kriegcloud/effect-jetbrains-plugin - JetBrains plugin for @effect/tsgo and DevTools.
• rashedInt32/effect-error-pretty.nvim - Neovim formatter that renders Effect, Stream, and Layer type mismatches as channel-aware boxes.
• nikelborm/effect-language-service-repro - Reproductions for language service issues.

Linting and code style

• Effect-TS/eslint-plugin - Official ESLint rules.
• OperationalFallacy/biome-effect-linting-rules - Biome Grit rules for Effect, published as @catenarycloud/linteffect.
• mpsuesser/oxlint-plugin-effect - Opinionated oxlint plugin for
• mpsuesser/effect-oxlint - Write oxlint custom rules with
• cevr/effect-oxlint - Strict, non-type-aware oxlint plugin that blocks Promise control flow and imperative failure handling in Effect code.
• EduSantosBrito/effect-rules - Rules for oxlint that catch untyped error channels and unsafe boundary parsing.
• zaniluca/effect-rules - Rules for oxlint with companion remediation skills.
• opsydyn/oxlint-effect - Rules for oxlint.
• tiara-stack/native-tooling - Rules for tsgolint.
• effect-app/tsgolint-fork - Fork of oxlint-tsgolint with a model codegen subcommand.
• aiya000/haskellish-effect-ts - ESLint plugin and config enforcing Haskell-like discipline.
• danielo515/effect-ast-grep-rules - ast-grep rules for Effect projects, tested on Effect v3.
• Effect-TS/slopcop - GitHub bot that triages pull requests on the Effect repo. Written with Effect, deployed to Cloudflare via Alchemy.

Scaffolding and migration

• Effect-TS/codemod - Official codemods. Last updated 2024.
• aridyckovsky/effect-migrate - Migration toolkit for adopting Effect with coding agents.
• deracs/create-effect-project - npx create-effect-project scaffolds an HttpApi server, plain program, or Cloudflare Worker on Node or Bun for Effect v4.
• rxssula/effect-http-starter - Scaffold HTTP server projects with CRUD endpoints, health checks, Scalar docs, and OpenAPI output.
• lloydrichards/stack-effect - Scaffold applications with community conventions.
• samuelho-dev/monorepo-library-generator - Generate Effect libraries in Nx monorepos.
• coffeeispower/create-ben-app - Bun, Effect, and Next.js scaffolder.
• mmlngl/steiger - Scaffold DDD modules with Effect.
• jpb06/bump-package - GitHub Action that bumps versions from commit messages, written with Effect.
• jpb06/coverage-badges-action - GitHub Action for coverage badges, written with Effect.
• effect-patterns-cli - Search and install patterns from EffectPatterns.

Playgrounds and visualizers

• Effect Playground - Official in-browser editor.
• kitlangton/visual-effect - Interactive visualizations of Effect programs. Site.
• effect-atom visualizer - Interactive examples for effect-atom, also by Kit Langton.
• topheman/effect-viz - Runtime visualizer with fiber tree, timeline, and execution log. Site.
• effect-ts.vercel.app playground - Browser-only playground with no server.
• srdjan/visual-effect-deno-ssr - Interactive visualizations rendered server-side with Deno.

Effect in other languages

Ports and libraries that borrow Effect's design outside TypeScript.

• Industrial/id_effect - Rust Effect<A, E, R> with context, layers, and pipe.
• Almaju/effect-rs - Functional effect framework for Rust inspired by Effect.
• SylphxAI/effect - Functional programming utilities for Dart inspired by Effect. Archived in 2026.
• tim-smart/elemental - Effect system and dependency management for Dart. Last updated 2024.
• lachenmayer/SwiftEffect - Experimental effect system for Swift inspired by ZIO and Effect. Last updated 2025.
• kevin-lee/effectie - Tool for FP effect libraries in Scala.
• ZIO - The Scala library Effect's design descends from.
• thefrontside/effection - Structured concurrency for JavaScript, a different design. Has an @effectionx/effect-ts bridge.

Other lists

• foldhub/awesome-foldkit - Foldkit projects, UI kits, agent tools, and apps, with star and download counts refreshed daily.
• m9tdev/awesome-effect - Earlier list, last updated July 2025.
• evryg-org/awesome-effect-ts - Short list from Evryg.
• betalyra/awesome-effect-ts - List from Betalyra.
• lvndry/awesome-effect-ts - List with a contribution checklist.
• sundaray/awesome-effect - Learning resources.
• marbemac/llms-effect - Repositories picked for LLM-assisted learning.

Contributing

See CONTRIBUTING.md. Entries must exist, must be reachable, and must say what the thing does. Run bun run check before opening a pull request.