// spam filtering api for forms

Anti-junk email API

One API call tags and/or blocks every submission before you email it.

Get your API key Read the docs

Free to start · no credit card · unlimited websites

live — /api/v1/checklive — form → /api/v1/check → inbox

everything stored & labeled · junk never emailed

No IP tracking, ever
Three layers, cheapest first
One key, every site
Spam caught in ~240ms
Unlimited websites
Free: 100 checks/mo

× how it works

Most form mail is junk — and you pay to send it.

Three layers, cheapest first — junk never reaches the AI.

Layer 01 — Free

Domain reputation

Throwaway domains flagged against a daily blocklist.

Layer 02 — Free

Sender reputation

Known spammers caught by a global abuse database.

Layer 03 — AI

Content check

The rest goes to a brand-tuned LLM: category, score, reason.

// deliberate omission

We never check IP addresses

IP reputation is noisy and punishes VPNs — we skip it.

× features

Built for the form handler, not the marketing site.

Drop it into any handler and let it filter — API-first.

001

Smart categorization

Every submission tagged spam, solicitor, lead, or support.

002

Custom categories

On Pro, add your own categories or switch off the defaults.

003

Brand-tailored AI

On Pro, train it on your site so leads are matched without waiting on a full AI pass.

004

Learns from corrections

Relabel once; it remembers similar mail next time.

005

Follow-up replies

Reply from the dashboard with AI drafts, sent via your Resend.

006

Own your data

Export to CSV or JSON, delete anything, on any plan.

007

Works with any integration

A plain HTTP endpoint — if it can fetch, it works.

008

One key, every site

One API key for every form and site. Rotate anytime.

009

Metrics that matter

Checks, category breakdowns, and a full submission log.

× see it in action

Request in, verdict out.

Send a submission, get back a verdict you can branch on.

requestsent ✓

POST /api/v1/check
Authorization: Bearer ig_live_xxx

{
  "email": "growth@bestseoagency.biz",
  "name": "Kyle from BestSEO",
  "message": "We can get you to page 1
             of Google. Reply for quote!"
}

response

{
  "category": "solicitor",
  "isSpam": true,
  "confidence": 0.94,
  "reason": "Unsolicited SEO pitch
             from a cold sender.",
  "signals": {
    "disposableDomain": false,
    "senderReputation": "suspicious"
  }
}

× drop-in integration

One fetch, wired in.

Paste into your form handler and branch on the verdict.

app/api/contact/route.ts

const res = await fetch(
  "https://sendworth.dev/api/v1/check",
  {
    method: "POST",
    headers: {
      "Authorization": `Bearer ${SENDWORTH_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      email: submission.email,
      name: submission.name,
      message: submission.message,
    }),
  }
)

const { category, isSpam } = await res.json()
// "lead" | "spam" | "solicitor" | "support-request"

if (!isSpam) {
  await resend.emails.send({ /* real mail only */ })
}

× pricing