Weight Tracking API

Track and manage body weight logs over time.

Base URL

http://localhost:3000/api/weights

All endpoints require authentication.

---

Log Weight

Record a new body weight measurement.

Endpoint: POST /weights

Headers:

Authorization: Bearer {token}
Content-Type: application/json

Request Body:

{
  "weightKg": 85.5,
  "recordedAt": "2026-02-23T08:00:00.000Z"
}

Fields:

• weightKg (required): Weight value in kilograms
• recordedAt (optional): ISO timestamp of when the measurement was taken — defaults to now

Response: 201 Created

{
  "id": "weight-log-uuid",
  "userId": "user-uuid",
  "weightKg": 85.5,
  "recordedAt": "2026-02-23T08:00:00.000Z"
}

Note: This also updates latestWeightKg in your profile automatically.

Errors:

• 400 - weightKg is required
• 401 - Unauthorized

---

Get Weight History

Retrieve weight logs for the current user, ordered by date ascending (suitable for charting).

Endpoint: GET /weights/history

Headers:

Authorization: Bearer {token}

Query Parameters:

Param	Type	Description
range	string	Time range filter (see below)

Range values:

Value	Description
1W	Last 7 days
1M	Last 30 days
3M	Last 3 months
6M	Last 6 months
1Y	Last 12 months
ALL	All time (up to 5000 entries)

If range is omitted, the last 100 entries are returned.

Response: 200 OK

[
  {
    "id": "weight-log-uuid",
    "userId": "user-uuid",
    "weightKg": 84.2,
    "recordedAt": "2026-02-01T08:00:00.000Z"
  },
  {
    "id": "weight-log-uuid-2",
    "userId": "user-uuid",
    "weightKg": 85.5,
    "recordedAt": "2026-02-23T08:00:00.000Z"
  }
]

Errors:

• 401 - Unauthorized

---

Example Usage

Log a New Weight

const weightLog = await fetch("http://localhost:3000/api/weights", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${token}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    weightKg: 85.5,
    recordedAt: new Date().toISOString(),
  }),
}).then((r) => r.json());

Get Weight History for Charting

// Last 3 months — good default for a weight trend chart
const history = await fetch(
  "http://localhost:3000/api/weights/history?range=3M",
  { headers: { Authorization: `Bearer ${token}` } },
).then((r) => r.json());

// history is ordered oldest → newest, ready to pass to a chart library
const chartData = history.map((log) => ({
  x: log.recordedAt,
  y: log.weightKg,
}));

• "After vacation"

Integration with Profile

When you log a weight:

1. A new entry is created in weight_logs table
2. Your profile's latestWeightKg is automatically updated
3. The profile page displays this latest weight
4. BMI is recalculated based on the new weight

This means:

• No need to manually update your profile weight
• Always shows your most recent measurement
• Historical data is preserved in weight logs