TMNL File Organization

Navigate TMNL's sophisticated modular architecture with confidence. This skill maps the directory structure, explains the lib/ vs components/ split, and guides you to the right file for any task.

Overview

TMNL follows a strict separation of concerns:

•src/lib/ — Reusable logic, services, atoms, hooks (framework-agnostic)
•src/components/ — React UI components (framework-specific)
•src/components/testbed/ — Isolated component demonstrations at /testbed/* routes
•assets/documents/ — Architecture docs, ADRs, design artifacts
•.edin/ — EDIN methodology files (patterns, testing, service docs)
•.agents/ — Session journals and context files

Canonical Sources

Primary Navigation Map

code

packages/tmnl/
├── src/
│   ├── lib/                    # Logic layer (Effect services, atoms, utilities)
│   │   ├── <domain>/
│   │   │   ├── v1/             # Versioned implementations
│   │   │   ├── v2/
│   │   │   ├── services/       # Effect.Service definitions
│   │   │   ├── atoms/          # effect-atom state atoms
│   │   │   ├── hooks/          # React hooks consuming atoms/services
│   │   │   ├── types.ts        # TypeScript interfaces
│   │   │   ├── index.ts        # Public exports
│   │   │   └── *.md            # Domain-specific docs (ARCHITECTURE, CLAUDE, README)
│   │   └── ...
│   ├── components/             # Presentation layer (React components)
│   │   ├── testbed/            # Testbed demonstrations
│   │   ├── <domain>/           # Domain-specific UI
│   │   ├── primitives/         # Base UI building blocks
│   │   ├── ui/                 # shadcn/ui components
│   │   └── ...
│   └── pages/                  # Route components
├── assets/
│   └── documents/              # Architecture docs, ADRs
├── .edin/                      # EDIN patterns (EFFECT_PATTERNS, TESTING, etc)
├── .agents/                    # Session journals
└── .beads/                     # Issue tracking database

Submodules Reference

Located at ../../submodules/ (from packages/tmnl):

code

submodules/
├── effect/                     # Effect-TS core library
│   └── packages/*/test/        # Canonical Effect test patterns
├── effect-atom/                # Reactive atoms for Effect
│   └── packages/atom/test/     # Atom test patterns
├── website/                    # Effect documentation (human-authored)
│   └── content/src/content/docs/
├── ag-grid/                    # AG-Grid source
├── anime/                      # anime.js animation library
├── GSAP/                       # GSAP animation library
└── xstate/                     # XState state machines

Patterns

lib/ Structure Pattern

Every src/lib/<domain>/ follows this canonical layout:

code

src/lib/<domain>/
├── v1/                         # Current stable version
│   ├── index.ts                # Public API exports
│   ├── types.ts                # TypeScript types/interfaces
│   ├── services/               # Effect.Service implementations
│   │   └── <ServiceName>.ts
│   ├── atoms/                  # effect-atom state atoms
│   │   └── index.ts
│   ├── hooks/                  # React hooks (useAtomValue, custom hooks)
│   │   └── use<Domain>.ts
│   ├── components/             # (rare) domain-specific components
│   └── <other>/                # kernels, effects, traits, etc.
├── v2/                         # Experimental/next version
├── ARCHITECTURE.md             # Deep technical design doc
├── CLAUDE.<domain>.md          # Agent handoff guide
├── README.md                   # User-facing quick reference
└── index.ts                    # Version-agnostic public exports

Versioning Convention:

•v1/ — Production-ready, stable API
•v2/ — Experimental, breaking changes expected
•Root index.ts — Delegates to current version (usually v1)

components/ Structure Pattern

code

src/components/<domain>/
├── <ComponentName>.tsx         # Main component file
├── components/                 # Subcomponents (if complex)
│   ├── <SubComponent>.tsx
│   └── index.ts
├── <context>.tsx               # React Context (if needed)
└── index.ts                    # Public exports

Key Differences from lib/:

•Components are React-specific (JSX/TSX files)
•Components consume lib services/atoms via hooks
•No direct Effect.Service definitions (use src/lib/)

Testbed Pattern

Testbeds demonstrate components in isolation at /testbed/<feature> routes.

Location: src/components/testbed/<Feature>Testbed.tsx

Examples:

•DataManagerTestbed.tsx → /testbed/data-manager
•SliderV2Testbed.tsx → /testbed/slider
•AnimationTestbed.tsx → /testbed
•VariablesTestbed.tsx → /testbed/variables

Route Registration: In src/router.tsx, add:

tsx

<Route path="/testbed/<feature>" element={<FeatureTestbed />} />

Service Pattern (Effect.Service)

Location: src/lib/<domain>/services/<ServiceName>.ts

Structure:

typescript

import { Context, Effect, Layer } from "effect";

export class MyService extends Context.Tag("tmnl/<domain>/MyService")<
  MyService,
  MyServiceInterface
>() {
  static Default = Layer.succeed(this, {
    // implementation
  });
}

Usage in Atoms:

typescript

// src/lib/<domain>/atoms/index.ts
export const myRuntimeAtom = Atom.runtime(
  Layer.mergeAll(MyService.Default, OtherService.Default)
);

export const myAtom = myRuntimeAtom.atom(
  Effect.gen(function* () {
    const service = yield* MyService;
    return yield* service.someMethod();
  })
);

Atom Pattern (effect-atom)

Location: src/lib/<domain>/atoms/index.ts

Standard Atoms:

typescript

import { Atom } from "@effect-atom/atom-react";
import { Effect } from "effect";

// Runtime atom combines service layers
export const runtimeAtom = Atom.runtime(
  Layer.mergeAll(ServiceA.Default, ServiceB.Default)
);

// Derived atom reads from service
export const stateAtom = runtimeAtom.atom(
  Effect.gen(function* () {
    const service = yield* ServiceA;
    return yield* service.getState();
  })
);

// Operation atom mutates state
export const opsAtom = {
  doAction: runtimeAtom.fn(
    Effect.gen(function* (input: string) {
      const service = yield* ServiceA;
      yield* service.performAction(input);
    })
  ),
};

Usage in React:

tsx

import { useAtomValue } from "@effect-atom/atom-react";
import { stateAtom, opsAtom } from "@/lib/<domain>/atoms";

function MyComponent() {
  const stateResult = useAtomValue(stateAtom);
  const doAction = opsAtom.doAction;

  const state = Result.isSuccess(stateResult) ? stateResult.value : null;

  return <button onClick={() => doAction("input")}>Act</button>;
}

Hook Pattern

Location: src/lib/<domain>/hooks/use<Domain>.ts

Purpose: Encapsulate atom consumption with cleaner API

typescript

import { useAtomValue } from "@effect-atom/atom-react";
import { stateAtom, opsAtom } from "../atoms";

export function useDomain() {
  const stateResult = useAtomValue(stateAtom);
  const state = Result.isSuccess(stateResult) ? stateResult.value : null;

  return {
    state,
    isLoading: Result.isPending(stateResult),
    error: Result.isFailure(stateResult) ? stateResult.cause : null,
    doAction: opsAtom.doAction,
  };
}

Examples

Example 1: Finding a Service

Task: Locate the DataManager service

Process:

•Check src/lib/data-manager/ (domain directory)
•Open v1/DataManager.ts (service file)
•Check v1/atoms/index.ts for runtime atom
•Check v1/hooks/useDataManager.ts for React hook

Files:

•Service: src/lib/data-manager/v1/DataManager.ts
•Atoms: src/lib/data-manager/v1/atoms/index.ts
•Hook: src/lib/data-manager/v1/hooks/useDataManager.ts
•Types: src/lib/data-manager/v1/types.ts

Example 2: Finding a Testbed

Task: View the slider testbed demonstration

Process:

•Check src/components/testbed/ directory
•Find SliderV2Testbed.tsx
•Visit /testbed/slider route in browser

File: src/components/testbed/SliderV2Testbed.tsx

Example 3: Finding Architecture Docs

Task: Understand DataManager architecture

Process:

•Check src/lib/data-manager/ARCHITECTURE.md (deep technical)
•Check src/lib/data-manager/CLAUDE.data-manager.md (agent guide)
•Check src/lib/data-manager/README.md (quick reference)

Files:

•Architecture: src/lib/data-manager/ARCHITECTURE.md
•Agent Guide: src/lib/data-manager/CLAUDE.data-manager.md
•Quick Ref: src/lib/data-manager/README.md

Example 4: Finding Effect Patterns

Task: Learn how to test Effect services

Process:

•Check .edin/EFFECT_TESTING_PATTERNS.md (TMNL-specific patterns)
•Check ../../submodules/effect/packages/*/test/ (canonical examples)
•Check .edin/EFFECT_PATTERNS.md (comprehensive registry)

Files:

•TMNL Patterns: .edin/EFFECT_TESTING_PATTERNS.md
•Canonical Tests: ../../submodules/effect/packages/sql-sqlite-bun/test/Client.test.ts
•Pattern Registry: .edin/EFFECT_PATTERNS.md

Example 5: Finding AG-Grid Integration

Task: Locate AG-Grid theme tokens and custom renderers

Process:

•Check src/lib/data-grid/theme/tokens.ts (design tokens)
•Check src/lib/data-grid/renderers/ (custom cell renderers)
•Check src/lib/data-grid/variants/ (theme variants)
•Check assets/documents/AG_GRID_THEMING_ARCHITECTURE.md (deep dive)

Files:

•Tokens: src/lib/data-grid/theme/tokens.ts
•Renderers: src/lib/data-grid/renderers/IdCellRenderer.tsx
•Variants: src/lib/data-grid/variants/tmnl-dense-dark.ts
•Docs: assets/documents/AG_GRID_THEMING_ARCHITECTURE.md

Anti-Patterns

❌ DON'T: Mix Logic in Components

tsx

// WRONG: Service logic in component
function MyComponent() {
  const [data, setData] = useState([]);

  useEffect(() => {
    // Complex business logic here
    const result = doComplexCalculation();
    setData(result);
  }, []);
}

✅ DO: Extract to lib/ service/atom

typescript

// src/lib/my-domain/services/MyService.ts
export class MyService extends Context.Tag(...) {}

// src/lib/my-domain/atoms/index.ts
export const dataAtom = runtimeAtom.atom(
  Effect.gen(function* () {
    const service = yield* MyService;
    return yield* service.calculate();
  })
);

// Component consumes atom
function MyComponent() {
  const dataResult = useAtomValue(dataAtom);
  const data = Result.isSuccess(dataResult) ? dataResult.value : [];
}

❌ DON'T: Create Atoms in Component Scope

tsx

// WRONG: Atom defined inside component
function MyComponent() {
  const myAtom = Atom.make(0); // Recreated on every render!
}

✅ DO: Define atoms at module level or in atoms/index.ts

typescript

// src/lib/my-domain/atoms/index.ts
export const myAtom = Atom.make(0);

// Component uses stable reference
function MyComponent() {
  const value = useAtomValue(myAtom);
}

❌ DON'T: Use useState for Cross-Component State

tsx

// WRONG: Prop drilling useState
function Parent() {
  const [state, setState] = useState(0);
  return <Child state={state} setState={setState} />;
}

✅ DO: Use atoms for shared state

typescript

// src/lib/my-domain/atoms/index.ts
export const sharedAtom = Atom.make(0);

// Both components consume atom
function Parent() {
  const value = useAtomValue(sharedAtom);
}
function Child() {
  const value = useAtomValue(sharedAtom);
}

❌ DON'T: Mix Versioned and Unversioned Code

typescript

// WRONG: Importing from v1 directly
import { MyService } from "@/lib/my-domain/v1/services/MyService";

✅ DO: Import from version-agnostic index

typescript

// CORRECT: Import from root index
import { MyService } from "@/lib/my-domain";
// Root index.ts delegates to current version (v1)

❌ DON'T: Put Effect.Service in components/

tsx

// WRONG: Service in components/
// src/components/my-ui/MyService.ts
export class MyService extends Context.Tag(...) {}

✅ DO: Services belong in lib/

typescript

// CORRECT: Service in lib/
// src/lib/my-domain/services/MyService.ts
export class MyService extends Context.Tag(...) {}

Quick Reference

File Location Cheatsheet

What You're Looking For	Where to Find It
Effect Service	`src/lib/<domain>/services/<Service>.ts`
effect-atom atoms	`src/lib/<domain>/atoms/index.ts`
React hooks	`src/lib/<domain>/hooks/use<Domain>.ts`
React components	`src/components/<domain>/<Component>.tsx`
Testbed demos	`src/components/testbed/<Feature>Testbed.tsx`
Architecture docs	`src/lib/<domain>/ARCHITECTURE.md` or `assets/documents/`
Effect patterns	`.edin/EFFECT_PATTERNS.md`
Testing patterns	`.edin/EFFECT_TESTING_PATTERNS.md`
Effect tests (canonical)	`../../submodules/effect/packages/*/test/`
Effect docs (human)	`../../submodules/website/content/src/content/docs/`
Session journals	`.agents/val/journal/<date>.md`

Common Commands

bash

# Find a component
find src/components -name "*MyComponent*"

# Find a service
find src/lib -name "*Service.ts"

# Find all testbeds
ls src/components/testbed/

# Find architecture docs
find assets/documents -name "*.md"

# Find EDIN patterns
ls .edin/

# Check submodule docs
ls ../../submodules/website/content/src/content/docs/docs/