Caliber
Block spam calls. Report them. Build the open database that kills them for everyone.
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Spam numbers
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Reports filed
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Last 24h
Block
Android's CallScreeningService backed by a local database. Spam calls never ring.
Report
One tap to report a number. Every report strengthens the database for everyone.
Open database
Free API. No walled gardens. Look up any number, pull the full dataset, build on top of it.
Look up a number
Get an API key
30-day free trial. After that, $39/year -- unlimited lookups, bulk sync, higher rate limits. No approval queue. Log in with your email to generate and manage keys.
Log in to dashboardAPI
Base URL: https://calliber.app. All responses are JSON. API key optional for lookups, required for bulk sync.
GET
/lookup?number=+15551234567
Look up a phone number. Returns report count, risk level, sources, first/last seen.
POST
/report
Report a spam number. Body:
{"number": "+15551234567", "callType": "robocall"}. Call types: robocall, telemarketer, scam, spoofed.
GET
/sync?since=2026-01-01T00:00:00Z
Delta sync. Returns numbers updated since the given timestamp. Paginated -- follow
hasMore with the returned checkpoint.
GET
/lookup/stats
Global stats: total spam numbers, total reports, reports in the last 24 hours.
POST
/keys/register
Register for an API key. Body:
{"name": "My app", "email": "you@example.com"}. Returns the key once -- save it.Authentication
Pass your key in the x-api-key header:
curl -H "x-api-key: cal_your_key_here" https://calliber.app/lookup?number=+15551234567