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how it works · REST API

The contact enrichment API with one shape for everything

The MoltSets API returns verified business and personal emails, carrier-verified mobile numbers, full business profiles and people and company search over plain HTTPS. Every tool takes the same request and returns the same envelope, so you can wire it into Clay, n8n, your CRM or your own product in an afternoon.

read the API docs get a free API key
what it is

B2B data enrichment over plain HTTPS

Give the API a piece of data you already have — an email, a LinkedIn URL, an IP address, or a name and company — and it returns the verified contact and company record behind it.

There is one base URL, one auth header and one response envelope across every tool. No SDK to install, no per-endpoint quirks. Browse every endpoint on the APIs page.

What you can call

  • / 01Search people and companies by title, seniority, industry, size and location
  • / 02LinkedIn URL → business, personal or best email
  • / 03LinkedIn URL → carrier-verified mobile phone
  • / 04Name + company domain → business email
  • / 05Reverse email and reverse LinkedIn lookup → full profile
  • / 06IP address → company
  • / 07Email or LinkedIn → SHA256 hashes and MAIDs for ad audiences
  • / 08Free account, billing and usage checks
use cases

Where teams plug the API in

01 / Clay waterfalls

Add MoltSets as an HTTP API step in a Clay table and use it as a step in your email or mobile waterfall.

02 / CRM enrichment

Fill in missing emails, titles and company data on new HubSpot or Salesforce records as they land.

03 / Workflow automation

Call it from n8n, Make or Zapier to enrich form fills, signups and inbound leads before they reach a rep.

04 / Lead list building

Search people and companies by title, seniority, industry, headcount and location, then enrich the results.

05 / Website visitor ID

Resolve visitor IPs to companies, or enrich RB2B and other de-anonymised visitors in bulk.

06 / Inside your product

Power enrichment in your own SaaS, data pipeline or agent framework with one consistent JSON contract.

setup

Key in, first record out.

  1. 01 /

    Get an API key

    Sign up free and create a key under API keys in the MoltSets app. Keys start with ms_.

  2. 02 /

    POST to a tool

    Every tool lives at /api/v1/tools/<tool_name>. Send JSON with your key as a Bearer token and any User-Agent.

  3. 03 /

    Read the envelope

    Every response has the same results, status and metadata. Check status to tell a hit from a miss.

1 shapeSame request and response for every tool
100Values per enrichment call
$0Charged when a lookup finds nothing
the request

One call, start to finish

This is the whole integration for a LinkedIn-to-email lookup. Swap the tool name in the path and the parameters in the body, and the same code calls any other endpoint.

Authentication guide →

POST /api/v1/tools/linkedin_to_best_email

curl -X POST https://api.moltsets.com/api/v1/tools/linkedin_to_best_email \
  -H "Authorization: Bearer ms_XXXXXXXXXXX" \
  -H "Content-Type: application/json" \
  -H "User-Agent: my-app/1.0" \
  -d '{"linkedin_url": "https://linkedin.com/in/example"}'

200 OK
{
  "results": { "email": "sam@example.com", "type": "business", "risk_score": "A", ... },
  "status": "ok",
  "metadata": { ... }
}
built for builders

Why developers pick MoltSets

01 / One request shape

Every tool is a POST with a JSON body. Learn one call and you know them all.

02 / Batch up to 100

Enrichment tools take up to 100 LinkedIn URLs or emails per call, with a per-item status in the response.

03 / Risk score on every email

Each email carries an A–F send-safety grade and its last validation date, so you decide who to mail.

04 / No charge on a miss

Lookups that find nothing return 200 with status: "not_found" and cost nothing.

pricing

What it costs

Every endpoint is included on every plan — there is no per-endpoint pricing. Unlimited plans are flat-rate, with limits set by records per window rather than per call. Full detail on the pricing page.

free

$0to start
Enrichment records1klifetime

Try before you commit, no card required.

get started
  • 1k data calls total
  • 100 search records total
  • Personal email included 

solo

$27/ month
Enrichment records1k/ 5 hours

For solo builders and small lists.

get started
  • Unlimited data
  • 500 search records / 5h
  • Personal email included 

pro MOST POPULAR

$97/ month
Enrichment records15k/ 5 hours

For teams enriching at scale.

get started
  • Unlimited data
  • 7.5k search records / 5h
  • Personal email included 

team

$397/ month
Enrichment records150k/ 5 hours

For teams that have outgrown the $97 limits.

get started
  • Unlimited data
  • 75k search records / 5h
  • Personal email not included 
help

Questions & answers about the MoltSets API

Integrating MoltSets over REST. Every endpoint, parameter and error code is in the developer docs.

It is a B2B contact data and identity resolution API. Send it an email address, LinkedIn URL, IP address, or a name and company, and it returns verified contact and company data — business and personal emails, carrier-verified mobiles, full profiles, and hashed emails for ad audiences. It also searches people and companies to build lists from scratch.

Pass your API key as a Bearer token in the Authorization header, and send any non-empty User-Agent. Keys look like ms_XXXXXXXXXXX and are created in the MoltSets app. You can create as many as you like — one per environment or agent is a good pattern.

The LinkedIn email tools, linkedin_to_mobile_phone and reverse_email_lookup accept up to 100 values per call. Pass linkedin_urls or emails as an array instead of the single parameter; each item counts as one request. The response reports each item with its own status, so a batch of 100 where 12 matched returns 12 hits and 88 misses in one 200.

No. A lookup that finds nothing returns HTTP 200 with status: "not_found" and costs nothing. It still counts as one request against your Fair Use requests limit. Read status, not the HTTP code, to tell a hit from a miss.

Limits are set by plan and shared across every key on the account. Unlimited plans don’t charge per lookup; they cap enrichment and search records, and requests, in rolling 5-hour and weekly windows under the Fair Use Policy. The full table is on the rate limits page.

Yes. Add an HTTP API column in Clay, point it at the tool you want and pass your key in the header. The Clay integration guide walks through it.

They lead to the same product, data and limits. Use the API to integrate MoltSets into a back-end, script or platform like Clay or n8n. Use the MCP server to work with MoltSets conversationally through Claude, ChatGPT or another AI agent.

Yes. The Free plan includes 1,000 API calls with no card, so you can try every endpoint before you commit. Account, billing and usage calls never cost anything.

Every email has been validated and carries its last validation date and an A–F risk score. Every mobile is carrier-verified, and landlines are never returned. Mobile lookups use phone tokens from a monthly subscription on paid plans — one per number found.

other ways to connect

Rather not write code?

AI Agents via MCP

Give Claude, ChatGPT, Cursor or any MCP client live access to verified contact data. Ask in plain English; the agent makes the calls.

how it works →

Chrome Extension

Enrich any LinkedIn profile from a side panel in one click, build lead lists as you prospect, and send them to HubSpot, Attio or Clay.

how it works →
moltsets console - PUBLIC BETA
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1,000 API calls, no card. MoltSets is in public beta — sign up and start calling the API today.

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