Now in public beta

semisift

The semi-permeable filter for your data.

One API call to decide if a change matters.

POST /v1/sift
{
  "old_state": "Product ABC — $10.75",
  "new_state": "...Product XYZ — $24.99 (NEW)",
  "criteria": "|"
}
What Is semisift

Natural language filtering for any state change.

SemiSift evaluates whether a change matters — using your criteria, written in plain English. Send an old state, a new state, and what you care about. Get back a boolean and a summary. That's the entire API.

Old State

"Product ABC — $10.75"

New State

"...XYZ — $24.99 (NEW)"

Your Criteria

"new products added"

semisift

relevance engine

Result

{ relevant: true }

How It Works

Three steps. One function.

01

Send

Post your old state, new state, and filtering criteria to a single endpoint. Text, JSON, markdown — any format.

POST /v1/sift

02

Sift

The engine evaluates relevance using your natural language criteria. Not regex. Not rules. The LLM understands the spirit of what you want.

confidence: 0.95

03

Act

Get back relevant: true or false, with a human-readable summary explaining what changed and why it matters — or doesn't — to you.

{ relevant: true }

Use Cases

One primitive. Infinite applications.

Webhook Filtering

Stripe sends 50 events per transaction. You care about 2.

only failed payments over $100

Agent Networks

Your agents poll every 60 seconds. Most checks find nothing.

when competitor pricing changes

Log Triage

10,000 errors per day. 3 need human attention.

errors affecting the checkout flow

Database Streams

Every row change fires an event. Most are irrelevant.

when EU customer permissions change

IoT / Sensors

Readings every second. Alerts should be rare.

temperature exceeds 80°F in server room

Content Monitoring

Pages change constantly. You care about specific changes.

when new products are added

Integrate

Five minutes to first sift.

bash
curl -X POST https://api.semisift.com/v1/sift \
  -H "Authorization: Bearer sk_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "old_state": "Product ABC — $10.75",
    "new_state": "Product ABC — $10.50, Product XYZ — $24.99 (NEW)",
    "criteria": "alert me when new products are added"
  }'

old_state

what it looked like before

new_state

what it looks like now

criteria

what you care about, in plain English

→ result

relevant: true + summary of what changed

Built on a validated heuristic.

The sift engine has been tested in production through NotifyBee, our website monitoring product.

0

inputs

old state, new state, criteria

<0

ms

average response time

0

endpoint

that's the entire API

Pricing

Start free. Scale as you grow.

Cheaper than building it yourself.

Free
$0/mo
  • 100 calls / month
  • Fast model
  • 10 req / minute
Starter
$29/mo
  • 5,000 calls / month
  • Both models
  • 60 req / minute
ProPopular
$99/mo
  • 50,000 calls / month
  • context[] support
  • 300 req / minute
  • Webhooks
Enterprise
Custom
  • Unlimited volume
  • Custom SLAs
  • SSO / SAML
  • Dedicated support