REST API
Count, browse, reveal and export leads; score contacts against your ICP; scrape company websites. One API key, JSON in and out. API overview →
LeadSonar Docs
Find the right people for your cold email, explained in plain words. Start here if you've never built a lead list, or jump straight to the API.
Every cold email setup has four parts
Section titled “Every cold email setup has four parts”LeadSonar is part 3: it decides who your emails go to. The other three parts decide whether they arrive.
Part 1 Infrastructure 
Maildeck Domains and inboxes you send from Part 2 Sequencer 
Instantly, PlusVibe… Sends emails and follow-ups Part 3That's us Leads 
LeadSonar The right people and their emails Part 4 Verification 
EmailShield Removes bad addresses first
Maildeck Domains and inboxes you send from Part 2 Sequencer Instantly, PlusVibe… Sends emails and follow-ups Part 3That's us Leads LeadSonar The right people and their emails Part 4 Verification EmailShield Removes bad addresses first Start here
Section titled “Start here” Cold email in 5 minutes The four parts, and why each one matters before you send a single email.
Your first 10 minutes Sign up, find your first 25 people, and download them as a CSV.
Credits and plans What a credit buys, what's free, and how to pick a plan.
Why fresh leads matter Contact data goes stale. Here's what that costs you, and how LeadSonar avoids it.
Build it into your own tools
Section titled “Build it into your own tools”For AI agents
Let your agent size a market, shortlist people and score their fit — free to explore, with guardrails on spending. LeadSonar for AI agents →
Every endpoint, today's schema
The reference is generated from our OpenAPI spec, checked against the live API on 6 October 2026. API reference →