How do I install the Effect Kit skill?

Run npx skillmds@latest add necmttn/effect-kit in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Effect Kit safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Effect Kit?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Effect Kit free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Effect Kit?

Necmttn (@necmttn) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Effect Kit by necmttn — Agent Skill

Name: Effect Kit
Author: Necmttn

File contents

effect-kit

[Evidence hook - measured via ax: a repo on the @effect/language-service plugin + raw tsc produced a recurring ~70-turn "is this advisory an error?" agent loop over 60 days; a sibling repo on tsgo + a central-filter gate (quera) had 0 such turns. Patterns adapted from Makisuo/skills (MIT); observability pairs with Maple (also Makisuo).]

Pillars

Setup → references/setup.md (tsgo + gate + severity table; one opinionated full setup)
Write → references/patterns.md (Makisuo's patterns + namespace imports) · large-codebase architecture → references/guide-effect-at-scale.md (schema packages, LayerNode, shared memoMap, HttpApi, SQL, transport-agnostic errors)
Verify → references/verify.md (diagnostics CLI + recipe pack; trust the exit code) · maintainer-pattern catalog → references/guide-maintainer-patterns.md (oxlint → grep → review)
Observe → references/observe.md (v4 Otlp.layerJson → Maple; Agent-Observe via devkit)

Install - run this checklist top to bottom (one todo per item)

1. Detect package manager + Effect version (bun/pnpm/npm; effect@4 RC - effect@rc on npm)
1. tsgo toolchain: npx @effect/tsgo setup (resolves current versions); merge assets/package.deps.json; pin in-repo
1. tsconfig: merge assets/tsconfig.snippet.json (plugin + ignoreEffectWarningsInTscExitCode + diagnosticSeverity table)
1. Gate: copy assets/effect-lint-staged.sh (chmod +x) + assets/lefthook.yml; lefthook install
1. Verify wiring: effect-language-service diagnostics --project ./tsconfig.json --severity error (expect exit 0)
1. CLAUDE.md: write the managed  block (verify rules + pillar pointers)
1. (optional) Observe: "wire local tracing with Maple?" → brew install Makisuo/tap/maple · maple start · copy assets/otel-maple.layer.ts · add effect (v4) · set MAPLE_TRACING=true
1. Smoke check: tsc --noEmit; echo $? is 0 on advisory-only; stage a file and confirm the gate fires on an error

---name: effect-kitdescription: The opinionated, agent-optimized way to set up, write, verify, and observe an Effect.ts codebase - tsgo + a central-filter gate + v4 OTLP. Use when setting up or hardening an Effect.ts repo for AI agents.---# effect-kit[Evidence hook - measured via ax: a repo on the @effect/language-service plugin + raw `tsc` produced a recurring ~70-turn "is this advisory an error?" agent loop over 60 days; a sibling repo on tsgo + a central-filter gate (quera) had 0 such turns. Patterns adapted from Makisuo/skills (MIT); observability pairs with Maple (also Makisuo).]## Pillars- **Setup** → references/setup.md (tsgo + gate + severity table; one opinionated full setup)- **Write** → references/patterns.md (Makisuo's patterns + namespace imports) · large-codebase architecture → references/guide-effect-at-scale.md (schema packages, LayerNode, shared memoMap, HttpApi, SQL, transport-agnostic errors)- **Verify** → references/verify.md (diagnostics CLI + recipe pack; trust the exit code) · maintainer-pattern catalog → references/guide-maintainer-patterns.md (oxlint → grep → review)- **Observe** → references/observe.md (v4 Otlp.layerJson → Maple; Agent-Observe via devkit)## Install - run this checklist top to bottom (one todo per item)- [ ] 1. Detect package manager + Effect version (bun/pnpm/npm; effect@4 RC - `effect@rc` on npm)- [ ] 2. tsgo toolchain: `npx @effect/tsgo setup` (resolves current versions); merge assets/package.deps.json; pin in-repo- [ ] 3. tsconfig: merge assets/tsconfig.snippet.json (plugin + ignoreEffectWarningsInTscExitCode + diagnosticSeverity table)- [ ] 4. Gate: copy assets/effect-lint-staged.sh (chmod +x) + assets/lefthook.yml; `lefthook install`- [ ] 5. Verify wiring: `effect-language-service diagnostics --project ./tsconfig.json --severity error` (expect exit 0)- [ ] 6. CLAUDE.md: write the managed `` block (verify rules + pillar pointers)- [ ] 7. (optional) Observe: "wire local tracing with Maple?" → brew install Makisuo/tap/maple · maple start · copy assets/otel-maple.layer.ts · add effect (v4) · set MAPLE_TRACING=true- [ ] 8. Smoke check: `tsc --noEmit; echo $?` is 0 on advisory-only; stage a file and confirm the gate fires on an error

Frequently asked questions

Effect Kit