# Engagement time series

`GET /v1/reports/engagement`

- Authentication: required (Bearer token)
- Required scope: `reports.view`

Time-bucketed open and click activity. Each bucket emits raw `sent`,
`delivered`, total `opens`/`clicks`, and `unique_opens`/`unique_clicks`
(distinct recipients who acted within the bucket).

Rate formulas:

- `open_rate = unique_opens / delivered`
- `click_rate = unique_clicks / delivered`

Both denominators are `delivered`, not `sent`, and the numerators are
**unique** counts. Ratios are in `[0, 1]`; zero `delivered` yields
`0.0`. Buckets align to UTC the same way as deliverability and empty
buckets are not zero-filled.

Caveat: for `week` and `month` buckets, a recipient who engages on
more than one day inside the bucket may be counted more than once in
`unique_opens`/`unique_clicks`. This matches the SendOps dashboard.
Default window is the trailing 30 days; plan retention applies.

## Query parameters

- `from` (string<date-time>, optional) — Window start (RFC 3339). Defaults to 30 days ago.
- `to` (string<date-time>, optional) — Window end (RFC 3339). Defaults to now.
- `group_by` (string enum, optional) — Time-bucket size for the report. UTC-aligned: `day` = midnight UTC;
`week` = Monday 00:00 UTC (ISO week); `month` = first of month
00:00 UTC. Buckets with no underlying events are omitted, not
zero-filled.
- `channel` (string<uuid>, optional) — Filter by channel UUID. Malformed values return `422 validation_failed`.
- `identity` (string, optional) — Filter by sending identity. Accepts a full email address (the
local-part is ignored — only the domain matches) or a bare domain.

## Example request

```bash
curl 'https://api.sendops.dev/v1/reports/engagement' \
  -H "Authorization: Bearer $SENDOPS_API_KEY"
```

## Responses

### 200 — Engagement buckets, oldest-first

Content type: `application/json`

```json
{
  "data": [
    {
      "period": "2026-05-17T20:00:00Z",
      "sent": 0,
      "delivered": 0,
      "opens": 0,
      "unique_opens": 0,
      "clicks": 0,
      "unique_clicks": 0,
      "open_rate": 0,
      "click_rate": 0
    }
  ]
}
```

### 401 — Missing, malformed, or unknown API key

Content type: `application/problem+json`

```json
{
  "type": "https://example.com",
  "title": "string",
  "status": 0,
  "detail": "string",
  "code": "invalid_key",
  "request_id": "string",
  "retry_after": 0,
  "retention_days": 0,
  "scope": "string",
  "resource": "string",
  "errors": [
    {
      "field": "string",
      "reason": "string"
    }
  ]
}
```

### 403 — Key lacks the required scope or plan limit violated

Content type: `application/problem+json`

```json
{
  "type": "https://example.com",
  "title": "string",
  "status": 0,
  "detail": "string",
  "code": "invalid_key",
  "request_id": "string",
  "retry_after": 0,
  "retention_days": 0,
  "scope": "string",
  "resource": "string",
  "errors": [
    {
      "field": "string",
      "reason": "string"
    }
  ]
}
```

### 422 — Query parameter or path value failed validation

Content type: `application/problem+json`

```json
{
  "type": "https://example.com",
  "title": "string",
  "status": 0,
  "detail": "string",
  "code": "invalid_key",
  "request_id": "string",
  "retry_after": 0,
  "retention_days": 0,
  "scope": "string",
  "resource": "string",
  "errors": [
    {
      "field": "string",
      "reason": "string"
    }
  ]
}
```

### 429 — Per-org rate limit exceeded

Content type: `application/problem+json`

```json
{
  "type": "https://example.com",
  "title": "string",
  "status": 0,
  "detail": "string",
  "code": "invalid_key",
  "request_id": "string",
  "retry_after": 0,
  "retention_days": 0,
  "scope": "string",
  "resource": "string",
  "errors": [
    {
      "field": "string",
      "reason": "string"
    }
  ]
}
```

### 500 — Unexpected server-side failure. The `code` is `internal_error`. The
`request_id` field can be quoted to SendOps support to investigate.

Content type: `application/problem+json`

```json
{
  "type": "https://example.com",
  "title": "string",
  "status": 0,
  "detail": "string",
  "code": "invalid_key",
  "request_id": "string",
  "retry_after": 0,
  "retention_days": 0,
  "scope": "string",
  "resource": "string",
  "errors": [
    {
      "field": "string",
      "reason": "string"
    }
  ]
}
```