People data in one API
Start from a phone, an email, a name, or an address and get back the rest — the person, their best callable number (with carrier and Do-Not-Call status), email, and household details. Two ways to use it: tell an AI assistant what you want, or call it yourself. New here? The 5-minute quickstart walks through every call on this page with copy-paste examples.
Just tell Claude what you want
You don’t have to write any code. Connect openappend to Claude (or any assistant that speaks MCP), then ask in plain English — the assistant figures out the calls, counts first, and only pulls what you confirm.
"Find homeowners in Dallas, TX, age 35–55, with a mobile
that isn't on the Do-Not-Call list. How many are there?
If it's under 5,000, pull their names and best number."
Or call it yourself
Plain JSON over HTTPS. Send your key as a bearer token. Base URL: https://api.openappend.com/v1.
curl https://api.openappend.com/v1/people/count \
-H "Authorization: Bearer oa_live_..." \
-H "Content-Type: application/json" \
-d '{ "filters": {
"state": "TX", "home_owner": true,
"age": { "between": [35, 55] },
"line_type": "mobile", "dnc": false
} }'
# → { "data": { "count": 128450 }, "meta": { "credits_used": 0 } }
curl https://api.openappend.com/v1/people/search \
-H "Authorization: Bearer oa_live_..." \
-H "Content-Type: application/json" \
-d '{ "filters": { "state": "TX", "home_owner": true },
"limit": 100 }'
# phones come back ranked callable-first — phones[0] is the one to dial.
Have one and want the other? Reverse a phone to an email, or an email to a phone.
curl https://api.openappend.com/v1/phone-to-email \
-H "Authorization: Bearer oa_live_..." \
-H "Content-Type: application/json" \
-d '{ "phone": "3125551234" }'
Read the field list at runtime instead of hard-coding it — new fields show up here automatically. The Playground builds these filters for you visually.
Authorization: Bearer oa_live_… on every request. Free endpoints (count, fields) work even at a zero balance, so you can always size an audience. Get a key →Common questions
How do I count people without revealing them?
POST to /v1/people/count with a filter set. It's free and returns a count only. Use this to size an audience before you pay to search with reveal:true.
What's the DNC flag and how does it protect me?
Every phone record carries a DNC flag showing whether the number is on the National Do Not Call Registry. Filter by dnc:false to exclude those numbers and reduce TCPA risk. Callable-first ranking means phones[0] is always the safest number to dial.
How much does it cost?
Free: count people and discover fields. 1 credit per revealed record when you set reveal:true. Prepaid credit packs, no subscription, no overage. Failed or empty requests never charge.
Can I use openappend in Claude or another MCP-aware agent?
Yes. Run the stdio server with npx -y @openappend/mcp, or connect the remote SSE endpoint at https://api.openappend.com/mcp. Configure it with your API key and the agent gets people_search, people_count, email_to_phone, and phone_to_email as tools.
Can I reverse a phone number to an email, or an email to a phone?
Yes. POST to /v1/phone-to-email or /v1/email-to-phone with the value you have. Returns matching contact(s) if available; misses are free, hits cost 1 credit.
What makes callable-first ranking different?
Most data providers return raw, unranked lists. openappend ranks each record's phones by dialability — live mobile first, then live landline, disconnected last — so phones[0] is always your best shot. This cuts wasted dials and DNC risk.