This and That - TaT

TaT is a solution for small task and record management, like a todo-list with a few extras:

• todo items with severity and optional deadline
• plain text records
• grouping of tasks and records
• spaces — shared containers granting equal access to all groups inside
• PWA application to be able to work offline with cached data

Tech stuff

Tech Stack

Library	Version	Purpose
Kotlin	2.3.0	Language / Native compiler (LLVM)
Ktor	3.4.2	HTTP server (CIO engine, native)
SQLDelight	2.3.2	Type-safe SQL, native SQLite driver
kotlinx-datetime	0.6.2	Multiplatform date/time
Detekt	1.23.8	Static analysis + formatting

Ktor Features

Name	Description
Default Headers	Adds a default set of headers to HTTP responses
Routing	Provides a structured routing DSL
Resources	Provides type-safe routing
Status Pages	Provides exception handling for routes
Content Negotiation	Provides automatic content conversion according to Content-Type and Accept headers
kotlinx.serialization	Handles JSON serialization using kotlinx.serialization library
SQLDelight	Type-safe SQL with native SQLite driver, no JVM required
Request Logging (custom)	Native-compatible plugin — logs every request as JSON line to stdout

Building & Running

The project compiles to a native binary via Kotlin/Native (LLVM backend). No JVM required at runtime. The target platform is selected automatically based on the host OS at build time.

Task	Description
./gradlew linkDebugExecutableNative	Compile debug binary
./gradlew linkReleaseExecutableNative	Compile optimized release binary
./gradlew runDebugExecutableNative	Compile and run debug binary
./gradlew allTests	Run tests for current platform
./gradlew detekt	Run linter

The compiled binary is output to:

build/bin/native/debugExecutable/todo.exe        # Windows
build/bin/native/debugExecutable/todo.kexe       # Linux / macOS
build/bin/native/releaseExecutable/todo.exe      # Windows release
build/bin/native/releaseExecutable/todo.kexe     # Linux / macOS release

Windows prerequisite

On Windows, SQLite is bundled as a static library in libs/windows/libsqlite3.a (compiled with Kotlin/Native's own clang — no MSYS2 or external toolchain required at build time).

CI

GitHub Actions runs on every push and pull request to main:

Job	Runner	What it does
lint	ubuntu-latest	Runs detekt (style + coroutines)
test	ubuntu-latest	Runs nativeTest (linuxX64)

Tests run only after lint passes. The Kotlin/Native toolchain (~/.konan) is cached between runs.

Detekt config: config/detekt/detekt.yml. Active rule sets: formatting, style, complexity, coroutines, naming.

API

The server listens on http://0.0.0.0:8080.

All timestamps are returned as ISO-8601 UTC strings. deadline is a local wall-clock datetime (YYYY-MM-DDTHH:mm:ss) with no timezone — the client owns timezone semantics for display.

Tasks

Method	Path	Body	Description
GET	/tasks	—	List all active tasks
GET	/tasks/{id}	—	Get task by ID
POST	/tasks	JSON	Create a new task
PATCH	/tasks/{id}	JSON	Partial update a task
DELETE	/tasks/{id}	—	Soft-delete a task

PATCH /tasks/{id} accepts optional groupId (string) to assign task to a group, or clearGroup: true to remove it from its group.

Records

Method	Path	Body	Description
GET	/records	—	List all active records
GET	/records/{id}	—	Get record by ID
POST	/records	JSON	Create a new record
PATCH	/records/{id}	JSON	Partial update a record
DELETE	/records/{id}	—	Soft-delete a record

PATCH /records/{id} accepts optional groupId / clearGroup: true (same as tasks).

Groups

Method	Path	Body	Description
GET	/groups	—	List all active groups
GET	/groups/{id}	—	Get group by ID
POST	/groups	JSON	Create group (title required, spaceId optional — defaults to private space)
PATCH	/groups/{id}	JSON	Update group: title?, spaceId? (move to space), clearSpace: true (move to private)
DELETE	/groups/{id}	—	Soft-delete group; items become ungrouped
POST	/groups/{id}/items	JSON	Add items to group atomically (new or existing tasks/records)

POST /groups/{id}/items accepts { "items": [...] } where each entry has a kind discriminator:

• "newTask" — creates a task in the group (name required, description/priority/deadline optional)
• "newRecord" — creates a record in the group (title required, content optional)
• "existingTask" — assigns an ungrouped task by id
• "existingRecord" — assigns an ungrouped record by id

All items are written in a single transaction — all succeed or all fail. Returns 400 if any item is not found or already belongs to a different group.

Spaces

Method	Path	Body	Description
GET	/spaces	—	List spaces accessible to caller (owned + member)
GET	/spaces/{id}	—	Get space by ID (owner or member)
POST	/spaces	JSON	Create space (title, max 200 chars)
PATCH	/spaces/{id}	JSON	Rename space (title) — owner only
DELETE	/spaces/{id}	—	Soft-delete space — owner only
GET	/spaces/{id}/members	—	List members — owner only
POST	/spaces/{id}/members	JSON	Add member (userId) — owner only
DELETE	/spaces/{id}/members/{userId}	—	Remove member — owner only

Every user has a private space (auto-created on first group creation). It cannot be deleted or have members added. Shared spaces are created explicitly via POST /spaces.

Groups are assigned to a space at creation time (spaceId in POST body) or later via PATCH /groups/{id}. If no spaceId is given at creation, the group goes into the caller's private space. clearSpace: true moves a group back to the private space.

PATCH /groups/{id} now accepts optional fields: title, spaceId (assign to space), clearSpace: true (remove from space).

Feed

Method	Path	Body	Description
GET	/feed	—	Unified paginated feed (groups + items)

Query params: limit (default 20, max 100), offset (default 0).

Feed response mixes groups (with children inline) and solo tasks/records, sorted by created_at desc. Each entry has a kind discriminator ("group", "task", "record").

Error responses:

Status	When
400	Malformed JSON, missing required fields, blank name
404	Resource not found
500	Unexpected server error

See bruno/ for a Bruno collection with ready-to-run requests.

to run locally: bru run --env local

Web UI (PWA)

SvelteKit 2 + Svelte 5 static SPA with PWA support. Lives in web/.

Library	Version	Purpose
SvelteKit	^2.57.0	App framework (static adapter)
Svelte	^5.55.2	UI (runes mode)
vite-plugin-pwa	^1.2.0	Service worker + manifest
TypeScript	^6.0.2	Type safety

Dev

cd web
npm install
npm run dev        # Vite dev server on :5173, proxies /tasks → localhost:8080

Backend must be running on localhost:8080 for API calls to work.

Build

npm run build      # Static output → web/build/
npm run preview    # Preview production build

Serve web/build/ with any static file server. Set VITE_API_URL env var when frontend and backend are on different origins:

# .env
VITE_API_URL=http://your-backend-host:8080

PWA

Manifest name: This and That / short name TaT. Icons expected at static/icons/icon-192.png and static/icons/icon-512.png. Service worker uses NetworkFirst for /tasks with 5 s timeout fallback to cache.

Database

SQLite database file tat.db is created in the working directory on first run. Schema is managed by SQLDelight — .sq files live in src/commonMain/sqldelight/. Migrations live in src/commonMain/sqldelight/migrations/ as <version>.sqm files.

Schema version is stored in SQLite's PRAGMA user_version. On startup the server automatically runs any pending migrations — no manual steps needed.

Timestamps (created_at, updated_at, deleted_at) are stored as Unix epoch milliseconds (UTC). deadline is stored as epoch milliseconds (UTC) and round-tripped as a local datetime — no server-side timezone conversion occurs.