# DNS SPF Lookup Budget

> DNS SPF Lookup Budget is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).

Counts DNS-triggering SPF mechanisms in a given SPF record against a configurable lookup budget to determine if the limit is exceeded

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/dns-spf-lookup-budget
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/dns-spf-lookup-budget-7517f79a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0OLS0THtWHnW7VCiC_2KM

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability dns-spf-lookup-budget-7517f79a -d '<json body>'
```

Example prompt: Check my SPF record 'v=spf1 include:_spf.google.com include:sendgrid.net include:mailchimp.com ~all' against a maximum of 10 DNS lookups and tell me if I'm within budget.

## When to prefer this

Choose this endpoint when you need a fast, stateless, deterministic check of SPF DNS lookup count against a budget — especially before publishing or caching an SPF record, debugging SPF permerror failures, or enforcing a custom lookup limit stricter than the RFC 7208 default of 10. Prefer this over live DNS resolution tools when you already have the SPF record text and want a bounded, offline computation with no external network calls.

## Known failure modes

- Malformed SPF record string may produce unexpected token counts or parsing errors
- Maximum budget value of zero or negative may return immediate fail status
- Extremely long SPF records near the 8192 character limit may be truncated or rejected
- Nested include chains are counted based on the record text provided, not live DNS resolution

## How this service works

DNS SPF Lookup Budget: DNS SPF Lookup Budget counts DNS-triggering SPF mechanisms against a configured budget from bounded caller-supplied values without an external provider. Call DNS SPF Lookup Budget before accepting, caching, redirecting, or retrying a caller-supplied web response. Returns normalized web evidence, the computed finding, and an explicit pass or advisory status for DNS SPF Lookup Budget as versioned deterministic JSON. Price: $0.001 USDC via x402 on Base. First-party, stateles…

## Output

Returns versioned deterministic JSON containing: the normalized SPF record evidence, the computed DNS lookup count, whether the count is within the configured budget, and an explicit pass or advisory status indicating compliance.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "record": {
   "type": "string",
   "maxLength": 8192,
   "description": "Record supplied to DNS SPF Lookup Budget; used only for this bounded calculation and processed in memory without retention."
  },
  "maximum": {
   "type": "integer",
   "description": "Maximum supplied to DNS SPF Lookup Budget; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "maximum": 10,
   "terminal": "-all",
   "mechanisms": [
    "include:a.example",
    "include:b.example",
    "mx",
    "-all"
   ],
   "within_budget": true,
   "dns_lookup_terms": 3
  },
  "schema": "delx/util-dns-spf-lookup-budget/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "59ce243626eaef239d274d03667e46eee898bb4ca5ecebb645c2679c97cdc137",
   "external_calls": 0
  },
  "operation": "web_reliability:dns_spf_lookup_budget"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/dns-spf-lookup-budget-7517f79a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)