Metrics

GET /api/v1/metrics returns the same daily counters the Metrics page shows, as JSON or CSV. Any key can read it, including Test keys. A domain-restricted key must name one of its domains.

Query

Parameter	Values	Default	Effect
days	1 to 90	30	Window that ends today (UTC).
domain	name or id	—	One domain instead of the organization total.
facet	provider, key, template, kind	—	Adds a by array: one row per mailbox provider, API key, template or kind.
key	string	—	With facet: only that key (for example gmail).
format	json, csv	json	CSV returns the series, or the breakdown when facet is set.

Response

{
  "object": "metrics",
  "days": 7,
  "domain": null,
  "series": [{ "day": "2026-08-16", "sent": 120, "delivered": 118, "bouncedHard": 1, "bouncedSoft": 1, "complained": 0, "opened": 40, "clicked": 9, "unsubscribed": 0 }],
  "totals": { "sent": 840, "delivered": 830, "bouncedHard": 4, "bouncedSoft": 6, "complained": 0, "opened": 300, "clicked": 61, "unsubscribed": 2 },
  "rates": { "delivery": 98.8, "bounce": 1.19, "hardBounce": 0.48, "softBounce": 0.71, "complaint": 0, "open": 35.7, "click": 7.26 },
  "facet": "provider",
  "by": [{ "key": "gmail", "label": "Gmail", "sent": 500, "delivered": 498, "bouncedHard": 1, "bouncedSoft": 1, "complained": 0, "opened": 200, "clicked": 40, "unsubscribed": 1, "delayed": 3, "blocked": 0 }]
}

delayed counts delivery delays. blocked counts replies the platform classified as a provider block or throttle (see Metrics & alerts).

Errors

Status	Code	Cause
403	forbidden_domain	A domain-restricted key asked for the organization total.
422	unknown_domain	The domain is not one this key may read.
422	validation_error	days outside 1 to 90, or an unknown facet.

Example

curl -H "Authorization: Bearer $F5SEND_API_KEY" \
  "https://api.f5send.com/api/v1/metrics?days=7&facet=provider&format=csv"

Usage

GET /api/v1/usage returns how much of your plan the organization has used. Any key can read it, including Test keys. The quota belongs to the organization, so a domain-restricted key sees the organization totals.

curl -H "Authorization: Bearer $F5SEND_API_KEY" https://api.f5send.com/api/v1/usage

{
  "object": "usage",
  "plan": "free",
  "emails": {
    "monthly": { "used": 120, "limit": 3000, "allowance": 3000, "overage": false, "resets_at": "2026-11-01T00:00:00.000Z" },
    "daily": { "used": 7, "limit": 100, "resets_at": "2026-10-15T00:00:00.000Z" }
  },
  "contacts": { "used": 42, "limit": 1000 },
  "rate_limit": { "limit": 10, "duration": "1s" }
}

Field	Meaning
emails.monthly.used	Live recipients counted this UTC month. Each recipient is one email.
emails.monthly.limit	The hard monthly limit. null means no cap. 0 means sending is stopped.
emails.monthly.allowance	The volume the plan includes.
emails.monthly.overage	true when mail past the allowance is billed, up to limit.
emails.daily	The same counter for the current UTC day. limit is null when the day has no cap.
contacts	Stored contacts and the plan allowance. limit is null when unlimited.
rate_limit	Requests per duration for the calling key.
resets_at	When the counter returns to 0 (UTC).

If the platform cannot read the counters, the call returns 503 usage_unavailable with Retry-After: 5.