sigtap - Email deliverability check: SPF, DKIM, DMARC and MX record audit for a sending domain
https://sigtap-outreach-api.sigtap.workers.dev/deliverability?domain=testOverview
x402 USDC on Base - no signup, the wallet is the account. Free check: GET https://sigtap-outreach-api.sigtap.workers.dev/preview/deliverability returns a 200 sample. Paid call in 3 steps: GET https://sigtap-outreach-api.sigtap.workers.dev/deliverability?domain=test -> 402 challenge (payTo+amount) -> sign and retry with the X-PAYMENT header (@x402/fetch does this) -> 200 + settled on-chain. Catalog + MCP twin: GET /llms.txt on this origin.
Protocol
x402
Price
$0.0030
Payment Asset
USDC
Payment Network
Base
Category
email-marketing
Provider
sigtap
Source
self-registered
Indexed
2026-09-05 13:45:06
Health
Status
healthy
Latency (p50)
644ms
Uptime (30d)
100.0%
Reliability Score
90/100
Last Checked
2026-09-15 17:28:07
Last Healthy
2026-09-15 17:28:07
Consecutive Failures
0
x402 Payment Validation
Payment Requirements
Valid
Asset Verified
Known USDC
Facilitator
—
Recent Health Checks
| Time | Status | HTTP | Latency | Error |
|---|---|---|---|---|
| 2026-09-15 17:28:07 | healthy | 402 | 594ms | |
| 2026-09-15 07:32:11 | healthy | 402 | 837ms | |
| 2026-09-14 19:19:25 | healthy | 402 | 644ms | |
| 2026-09-14 13:38:46 | healthy | 402 | 6051ms | |
| 2026-09-14 02:31:06 | healthy | 402 | 1084ms | |
| 2026-09-13 22:14:39 | healthy | 402 | 487ms | |
| 2026-09-13 06:57:27 | healthy | 402 | 558ms | |
| 2026-09-13 04:49:27 | healthy | 402 | 517ms |