mitbringsl/docs/API.md

# Mitbringsl – REST API Specification

Base URL: `/`
Authentication: Bearer Token via `Authorization: Bearer <session_token>` header or session cookie.

---

## Health & Diagnostics

### `GET /healthz`
Liveness probe. Returns HTTP 200 `OK`.

### `GET /readyz`
Readiness probe. Checks PostgreSQL connection pool health.
- **200 OK**: Database reachable.
- **503 Service Unavailable**: Database error.

---

## Authentication (`/auth`)

### `POST /auth/register`
Create a new email/password account.
- **Request**:
  ```json
  { "email": "user@example.com", "password": "secretpassword", "display_name": "Max" }
  ```
- **Response (201 Created)**:
  ```json
  {
    "token": "<opaque_session_token>",
    "expires_at": "2026-09-04T20:00:00Z",
    "user": { "id": "<uuid>", "email": "user@example.com", "display_name": "Max" }
  }
  ```

### `POST /auth/login`
Authenticate with email/password.
- **Request**:
  ```json
  { "email": "user@example.com", "password": "secretpassword" }
  ```
- **Response (200 OK)**: Same shape as register.

### `POST /auth/oidc`
Authenticate via Google or custom OpenID Connect provider.
- **Request**:
  ```json
  { "provider": "google", "id_token": "<jwt>" }
  ```
- **Response (200 OK)**: Same shape as login.

### `POST /auth/logout`
Revoke active session token. Returns `204 No Content`.

---

## Lists (`/api/lists`)

All list endpoints return `404 Not Found` when the authenticated user is neither
owner nor member of the list (no membership leaks), and `401` without a valid
session. List responses carry an `invite_code` (8 characters) for sharing.

### `GET /api/lists`
Fetch all active (non-deleted) lists the authenticated user owns **or** joined
as a member.
- **Response (200 OK)**:
  ```json
  {
    "lists": [
      { "id": "<uuid>", "name": "Wocheneinkauf", "invite_code": "A1B2C3D4", "updated_at": "2026-08-05T19:00:00Z", "hlc_ts": 177000000000000 }
    ]
  }
  ```

### `POST /api/lists`
Create a new list. The owner is automatically added to `list_members` (role
`owner`) and an invite code is generated.
- **Request**: `{ "name": "Supermarkt" }`
- **Response (201 Created)**: `{ "id": "<uuid>", "name": "Supermarkt", "invite_code": "A1B2C3D4", ... }`

### `GET /api/lists/{id}`
Fetch list detail including items (owner or member only).
- **Response (200 OK)**:
  ```json
  {
    "id": "<uuid>",
    "name": "Wocheneinkauf",
    "invite_code": "A1B2C3D4",
    "updated_at": "...",
    "hlc_ts": 177000000000000,
    "items": [
      { "id": "<uuid>", "name": "Milch", "quantity": "1L", "checked": false, "hlc_ts": 177000000000001 }
    ]
  }
  ```

### `POST /api/lists/{id}/invite`
Return the invite code of a list (owner or member only). Generates a code on
the fly for legacy lists without one.
- **Request**: empty JSON object `{}`
- **Response (200 OK)**: `{ "invite_code": "A1B2C3D4" }`

### `POST /api/lists/join`
Join a shared list using its invite code (case-insensitive). Joining again is
idempotent; the existing membership role is kept (an owner cannot be demoted).
- **Request**: `{ "invite_code": "a1b2c3d4" }`
- **Response (200 OK)**: the joined list (same shape as `GET /api/lists` items).
- **400 Bad Request**: unknown or empty invite code.

---

## Sync & Ops (`/api/lists/{id}/ops`)

Both endpoints require membership (owner or member); otherwise `404 Not Found`.

### `POST /api/lists/{id}/ops`
Push a batch of client operations (max 100).
- **Request**:
  ```json
  {
    "client_id": "<client_uuid>",
    "ops": [
      {
        "client_seq": 1,
        "op_type": "item_add",
        "target_id": "<item_uuid>",
        "hlc_ts": 177000000000000,
        "payload": { "name": "Brot", "quantity": "1 Stück" }
      }
    ]
  }
  ```
- **Response (200 OK)**:
  ```json
  {
    "results": [
      { "client_seq": 1, "seq": 42, "hlc_ts": 177000000000001 }
    ]
  }
  ```

### `GET /api/lists/{id}/ops?since={seq}`
Pull operations since server sequence `since`.
- **Response (200 OK)**:
  ```json
  {
    "ops": [
      {
        "seq": 42,
        "client_id": "<client_uuid>",
        "op_type": "item_add",
        "target_id": "<item_uuid>",
        "payload": { "name": "Brot" },
        "client_seq": 1,
        "hlc_ts": 177000000000001,
        "created_at": "2026-08-05T20:00:00Z"
      }
    ],
    "has_more": false
  }
  ```

---

## Suggestions (`/api/suggestions`)

### `GET /api/suggestions?q={query}`
Fuzzy autocomplete search for item names (pg_trgm).
- **Response (200 OK)**:
  ```json
  { "suggestions": ["milch", "mineralwasser", "müsli"] }
  ```