# AgentShelf DNS TXT SPF Lookup

> AgentShelf DNS TXT SPF Lookup is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-02).

Fetches the SPF TXT record (v=spf1...) from the DNS of a given hostname

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/dns-txt-spf?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentshelf-dns-txt-spf-lookup-a6774c39
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yl7fim0VYcFezNpAtamf0

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 agentshelf-dns-txt-spf-lookup-a6774c39 -d '<json body>'
```

Example prompt: Can you pull the SPF TXT record for github.com — I need to see what mail servers are authorized to send on its behalf?

## When to prefer this

Use this endpoint when you specifically need to retrieve the SPF TXT record (v=spf1) for a domain and want a simple, dedicated lookup without building DNS resolution infrastructure. Prefer the free sandbox endpoint (/v1/sandbox/dns-txt-spf) first if available; fall back to this paid endpoint when the sandbox is unavailable or rate-limited. Good fit for email deliverability checks, domain security audits, and mail server authorization verification.

## Known failure modes

- No SPF record found for the hostname — endpoint returns an error or empty result
- Hostname does not exist or is unreachable via DNS
- Malformed hostname input exceeding 253 characters
- Network timeout during DNS resolution
- Multiple SPF records present (technically invalid per RFC) — behavior may be undefined

## How this service works

Call when an agent needs apex TXT records that start with v=spf1. Fails when no SPF record exists. Exact $0.002 USDC. Prefer unpaid POST /v1/sandbox/dns-txt-spf first.

## Output

Returns the apex DNS TXT record for the given hostname that begins with 'v=spf1', representing the domain's Sender Policy Framework policy string. Fails with an error if no SPF record exists for the hostname.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "hostname": {
   "type": "string",
   "examples": [
    "example.com"
   ],
   "maxLength": 253,
   "minLength": 1,
   "description": "Public DNS hostname such as example.com. Not a URL, not an IP literal, and not a private name."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentshelf-dns-txt-spf-lookup-a6774c39/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)