Compute the exact SPF lookup cost across a supplied include tree
Compute the exact SPF lookup cost across a supplied include tree. The budget of ten resolving mechanisms is shared across the whole evaluation rather than per record, which is why a record with three includes can cost fourteen lookups and no single record looks wrong. Reports the total against the limit, the headroom left, a cycle in the include chain, and every include whose record was not supplied so the total is a floor.
Answeringour last check, 2026-10-04
1 of 1checks answered this week
5372 msmedian answer time
$0.18listed price per call
$0.18price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://api.zfinia.com/x402/v1/spf-include-budget-audit
| Category | Code and developer |
|---|---|
| Provider host | api.zfinia.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-04 | valid payment request | 402 | $0.18 | 5372 ms |
Example input (from the provider)
{
"body": {
"domain": "example.test",
"records": [
{
"domain": "example.test",
"record": "v=spf1 include:_spf.vendor-a.test include:_spf.vendor-b.test include:_spf.shared.test ~all"
},
{
"domain": "_spf.vendor-a.test",
"record": "v=spf1 a mx include:_spf.shared.test include:_spf.regional.test ip4:203.0.113.0/24 ~all"
},
{
"domain": "_spf.vendor-b.test",
"record": "v=spf1 a:mail.vendor-b.test mx include:_spf.vendor-a.test ip4:198.51.100.0/24 ~all"
},
{
"domain": "_spf.shared.test",
"record": "v=spf1 a mx exists:%{i}._auth.shared.test ip4:192.0.2.0/24 ~all"
},
{
"domain": "_spf.regional.test",
"record": "v=spf1 include:_spf.unsupplied.test a ~all"
}
]
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"domain": {
"maxLength": 253,
"type": "string"
},
"records": {
"items": {
"additionalProperties": false,
"properties": {
"domain": {
"maxLength": 253,
"type": "string"
},
"record": {
"maxLength": 4096,
"type": "string"
}
},
"required": [
"domain",
"record"
],
"type": "object"
},
"maxItems": 200,
"minItems": 1,
"type": "array"
}
},
"required": [
"domain",
"records"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}