01 · ping
Your tracker pings us
TrackDrive, Ringba, Retreaver, or anything that can fire a webhook posts the caller number to your lookup URL before the call routes.
POST /v1/your-company caller_number=+14155551234 api_key=fck_9f2…
Screen smarter. Protect revenue.
Know every callerbefore the callcosts you
CallerSift scores every inbound caller in real time, so your buyers answer genuine callers and fraud never reaches a payable minute.
1.2M+callers screened before v1
<300mstypical verdict time
0genuine callers blocked: fail-open
Live screening
A verdict before
the first ring
Your call tracker POSTs the inbound number to your lookup URL. CallerSift scores it against carrier-grade phone intelligence and answers allow or block in milliseconds, so the call routes on the verdict, not on hope.
High-risk lines never reach a payable minute; genuine callers connect like nothing happened.
screening · live
connectedLookups today
312
Allowed
268
Blocked
44
- 14:02•••• 4821 · mobileallow
- 14:00•••• 0937 · nonFixedVoipblock
- 13:57•••• 6644 · landlineallow
- 13:49•••• 2210 · premiumblock
- 13:31•••• 8590 · mobileallow
POST /v1/your-company · answers before the first ring
The flow
Ping Score Route
02 · score
We score the number
Our multi-source intelligence engine classifies the line in milliseconds over a redundant, high-availability scoring pipeline. Genuine reachable callers pass; disposable VoIP, premium-rate lines and other fraud-prone numbers do not.
score: fraud line_class: "disposable-voip" confidence: high
03 · route
You route on the answer
The response is one field your tracker can branch on. Real callers ring your buyers; fraud never costs a payable minute.
{
"verdict": "block",
"line_type": "nonFixedVoip",
"reason": "…"
}04 · cache
Verdicts cache for a day
A number scored once answers instantly for a day, and every verdict lands in our shared intelligence database: a number anyone on the network has scored never costs you a fresh lookup. And if a lookup cannot run, we fail open.
cached: true age: 316s fail_open: always
The dashboard
Every lookup, every verdict Live
Lookup KPIs, live
Totals, allow/block split, 7-day trend. The home screen is the screening desk.
Lookups
3,412
Allowed
2,981
Blocked
431
One-click test lookup
Fires a real lookup with your active key, exactly like your tracker will. The verdict lands in recent lookups.
+14155551234Test lookup
verdict: allow (mobile)
Zero-downtime keys
Add a key, switch the tracker, revoke the old.
fck_9f2…ed99 · activefck_11b…04af · revoked
Buyers answer real callers
Reads the line, not just the number
Every caller is classified in real time by our proprietary multi-source line-type intelligence engine before the call routes. The risk scoring stays on our side; your tracker just reads the verdict.
mobilelandlinefixedVoipnonFixedVoippremium+3 more
Fail-open, by design
If a lookup cannot run, the answer is allow. Zero genuine callers have ever been blocked by an outage.
lookup failed → { "verdict": "allow" }Plugs into
If it can fire a webhook, it can screen callers
One POST per inbound call, one field to route on. Step-by-step setup guides for every major platform are in the docs.
Pricing
One price Pay per lookup
$0.010 per lookup from a prepaid balance. No monthly fee, no subscription; a low balance alerts you well before anything pauses. Running serious volume? We negotiate.
Pay as you go
self-serveNothing to connect: lookups run on our line-type intelligence and debit a prepaid balance.
$0.010 /lookup
- No monthly fee, no subscription: your balance only spends on lookups
- Optional auto-recharge from your saved card
- Known numbers answer from our verdict database, no double spend
- Low balance alerts before screening ever pauses
- Every feature included: team seats, roles, API access
Bulk
negotiatedHigh call volume? We price it per lookup against the volume you commit to. Same engine, same features.
Let's talk /negotiated
- Your rate, negotiated on a monthly commitment
- Bigger the monthly commit, lower the per-lookup rate
- Invoiced monthly: no prepaid balance to watch
- A named contact who knows your traffic
- Every feature included: team seats, roles, API access
A card is required at signup for the opening top-up. Stop any time; nothing is ever deleted.
Questions
Asked before you ask
What exactly does CallerSift block?+
CallerSift scores every inbound caller in real time against our proprietary multi-source phone intelligence engine before the call routes. Genuine reachable callers pass; disposable VoIP, premium-rate lines and other fraud-prone numbers are blocked. You route on one field in the response.
Which countries do you support?+
CallerSift screens US and Canada caller numbers only. Any number from outside the US or Canada answers block with the reason marked out of region, so international callers never reach your buyers. Support for other regions is not on the roadmap; pay-per-call runs on US and Canada traffic, and so do we.
Can a real caller get blocked by an outage?+
No. The service fails open: if a lookup cannot run for any reason, the answer is allow. An outage can never cost you a genuine caller.
How is it priced?+
One price: pay as you go at $0.010 per lookup, debited from a prepaid balance. The opening top-up is $20 (later top-ups start at $5), auto-recharge is optional, and there is no monthly fee and no subscription. A card is required at signup; you add funds and screen from your first call.
Do I need my own carrier account or phone provider?+
No. Screening runs entirely on CallerSift's own intelligence infrastructure. There is nothing to connect and no carrier account to manage: point your call tracker at your lookup URL and screen.
What happens when a pay-as-you-go balance runs out?+
A low balance alerts you by email and in the app well before it matters, and auto-recharge (if enabled) tops up $20 from your saved card when the balance dips under $5. If the balance empties completely, screening pauses and the API answers 402 until you top up; your data, setup and history stay untouched.
Can I always allow or always block a specific number?+
Yes. Every workspace manages its own allow and block lists on the Lookups page: a listed number is decided instantly, before any scoring. You can also report a fraud caller from your lookup log, which blocks it across the whole CallerSift network for 180 days.
Which call trackers work with it?+
TrackDrive, Ringba and Retreaver have step-by-step guides, and anything that can fire a webhook per inbound call works: POST the caller number to your lookup URL, read allow or block from the response.
What caller data do you store?+
Your workspace's own lookup log keeps each caller number with its verdict and line type, so you can audit and export your screening history. Numbers are used only to run lookups and keep that log: the shared verdict store holds one-way hashes, never plain text, and numbers are never used for marketing or shared across workspaces in readable form.
16:04•••• your-buyers · mobileallow
Real callers only
Starting now
Every caller screened before the first ring.
One webhook to connect, one answer to route on.