How to Build a Free Lead Generation Stack (With Real Queries and Output)

TL;DR

• Size the audience for free, pull a page of contacts, enrich one person and export a CSV. No card needed at any step.
• It takes about 20 minutes and spends about 26 of your 1,000 free LeadOcean records.
• Free is one-off: 1,000 records for life, all features, 5 requests a second. Bulk CSV export needs Solo ($97 a month).

Free lead gen tools fall into three jobs: find the audience, get the contact, and send the message. This guide covers the first two with a free API. For the third, any free mailbox and a spreadsheet will do at this volume.

The rule that saves money: size before you pull. Counting is free. Pulling is what spends records.

Free tools cover four jobs. Pick one tool per job and keep the stack small.

• Find the audience. Needs filters you can count against: title, level, function, country, headcount, industry. LeadOcean has 50 people filters and 34 company filters, and counting is free.
• Get the contact. Needs a verified email and, sometimes, a phone. Read email_status on every row.
• Check the fit. A company page, a LinkedIn profile or the site itself. A browser and ten minutes beat any scoring model at 25 rows.
• Send and track. A free mailbox and a spreadsheet work up to a few hundred contacts. Add a sequencer when replies need routing.

Prerequisites

• A free LeadOcean account at app.leadocean.io (no card).
• An API key, exported as $LEADOCEAN_API_KEY.
• curl and jq. Nothing else.

export LEADOCEAN_API_KEY="paste-your-key-here"

Step 1: Size the audience for free

Start with a count. A count spends no records, so run it as often as you like. The MCP tool leadocean_count_leads does the same job from Claude or any MCP client.

On the API, a search with count=true and limit=1 as query parameters is free. The count is capped at 100,000 in meta.total.

curl -s -X POST "https://api.leadocean.io/v1/people/search?count=true&limit=1" \
  -H "x-api-key: $LEADOCEAN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "jobLevel": ["Director"],
    "jobFunction": ["Sales & Business Development"],
    "country": ["DE"],
    "employeeRange": ["51-200"]
  }' | jq '.meta'

For companies, GET /v1/companies/count returns an exact total with breakdowns by industry, headcount band and HQ country. It is free too.

Step 2: Pull one page of contacts

Pull only when the count looks right. The body is flat JSON, filters are arrays, and limit runs from 1 to 100. A page of 25 spends 25 records.

curl -s -X POST "https://api.leadocean.io/v1/people/search" \
  -H "x-api-key: $LEADOCEAN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "jobLevel": ["Director"],
    "jobFunction": ["Sales & Business Development"],
    "country": ["DE"],
    "employeeRange": ["51-200"],
    "limit": 25
  }' > page1.json
jq '.meta' page1.json

For the next page, send the cursor value from meta in the next request. One search pages to 10,000 rows, then meta.depthCapped is true. Narrow the filters instead of walking further.

Step 3: Enrich one person

Search gives you the profile. Enrich gives you the full record. Pass exactly one of linkedin_url, email, phone or person_id. Set reveal_email to true to get the address.

curl -s -X POST "https://api.leadocean.io/v1/people/enrich" \
  -H "x-api-key: $LEADOCEAN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"linkedin_url": "https://www.linkedin.com/in/jane-doe-example", "reveal_email": true}'

A hit counts one record. An enrichment that finds nobody returns 404 and costs nothing. Since October 2026 the response also carries career history: past roles, education and certifications.

Step 4: Export a CSV

Free users can build and price an export in the app. In the app, open Exports, set the filters, pick columns and see the record price before you start. Bulk CSV download is not on the Free plan.

If you move to Solo, the same export runs from the API.

curl -s -X POST "https://api.leadocean.io/v1/exports" \
  -H "x-api-key: $LEADOCEAN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "filters": {
      "jobLevel": ["Director"],
      "jobFunction": ["Sales & Business Development"],
      "country": ["DE"]
    },
    "limit": 500
  }'

An export takes up to 50,000 rows a request and 500,000 a day.

Step 5: Run the same steps from Claude

LeadOcean ships a hosted MCP server at https://api.leadocean.io/mcp, with 13 tools. Sign-in is OAuth, so you paste no key. The free tools are leadocean_count_leads, leadocean_count_companies, leadocean_list_filters, leadocean_list_enum_values, leadocean_get_account, leadocean_get_export and leadocean_list_exports.

A prompt that stays free until you say go:

Count directors in sales and business development, based in Germany, at companies with 51-200 employees.
Show total, totalAll and distinctCompanies. Do not pull any records yet.

leadocean_search_leads and leadocean_get_lead spend one record per person returned. Ask the model to count first, then pull 25.

What you get

The count for Step 1, run on 2026-10-21 with the free leadocean_count_leads tool:

{
  "total": 1671,
  "totalIsExact": true,
  "totalAll": 6954,
  "distinctCompanies": 1301,
  "credits": 0
}

Read it carefully. total is the mailable audience: people whose best email is verified, catch_all_valid or catch_all. totalAll is the same filters with no email condition. credits 0 confirms the count was free.

A search page, response shape from the API reference, with placeholder values. Search rows carry email flags, not addresses.

{
  "success": true,
  "data": [
    {
      "profile_data": { "profile_full_name": "Jane Doe" },
      "contact_data": {
        "has_email": true,
        "email_status": "verified",
        "contact_current_experiences": [
          { "job_title": "Director of Sales", "company_name": "Acme", "company_domain": "acme.com" }
        ]
      },
      "meta": { "source_ids": { "person_id": "1234567890" } }
    }
  ],
  "meta": { "count": 1, "limit": 25, "credits": 1, "nextCursor": "NEXT_CURSOR" }
}

Troubleshooting

FAQ