Cold Email Lemlist

Cold Email — Vibe Prospecting + Lemlist

Build a targeted prospect list, enrich it with firmographic and contact data, have Claude write personalized emails for each prospect, and push everything to a live Lemlist campaign — ready to send.

What you'll end up with:

• A filtered, enriched prospect list with verified work emails
• A personalized first-line (icebreaker) and full email per prospect, written by Claude using their actual company data
• All leads uploaded to a Lemlist campaign with personalization variables pre-filled

Step 0 — Credential Check (Claude: always do this first)

Do not start Phase 1 until both checks pass.

Vibe Prospecting

Cowork mode: look for a tool matching mcp__*__fetch-entities in your tool list.

• ✅ Found → proceed
• ❌ Missing → tell the user: "Please connect the Vibe Prospecting connector from the connector store, then let me know when it's done." Wait. Do not continue until the tool appears.

Claude Code / terminal:

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npx @vibeprospecting/vpai@latest --help

• ✅ Lists tools → proceed
• ❌ Error → run: npx @vibeprospecting/vpai@latest config --api-key "YOUR_VP_API_KEY"

Lemlist API Key

Ask the user: "Please paste your Lemlist API key. I'll verify it and we'll get started."

Get it from: Lemlist → Settings → Integrations → API.

Once provided, verify:

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export LEMLIST_API_KEY="<key-from-user>"

curl -s "https://api.lemlist.com/api/team" \
  -u ":$LEMLIST_API_KEY" \
  | python3 -c "
import json, sys
d = json.load(sys.stdin)
print('✅ Connected —', d.get('name', 'team found')) if '_id' in d else print('❌ Failed:', d.get('message', 'unknown error'))
"

• ✅ Connected → tell the user "Both credentials verified — let's go." Proceed to Phase 1.
• ❌ Failed → ask the user to check the API key in Lemlist → Settings → Integrations → API. Do not proceed.

Phase 1 — Define Your ICP and Fetch Prospects

Ask the user for their targeting criteria if not already provided:

"Who are we targeting? Tell me: industry, company size, geography, job titles/levels, and any tech stack or funding signals you want to filter on."

Then run autocomplete for any controlled-vocab fields before fetching.

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# Normalize industry/category values first
npx @vibeprospecting/vpai@latest autocomplete \
  --args '{"field": "linkedin_category", "query": "<user industry>"}' \
  --tool-reasoning 'Normalize industry filter for cold email prospect list'

# Normalize job titles if needed
npx @vibeprospecting/vpai@latest autocomplete \
  --args '{"field": "job_title", "query": "<user job title>"}' \
  --tool-reasoning 'Normalize job title for cold email prospect list'

Sample 5 prospects first (full chain — do not stop after fetch to ask for approval):

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npx @vibeprospecting/vpai@latest fetch-entities --all-parameters

npx @vibeprospecting/vpai@latest fetch-entities \
  --args '{
    "entity_type": "prospects",
    "filters": {
      "job_level": {"values": ["<user levels>"]},
      "job_department": {"values": ["<user departments>"]},
      "linkedin_category": {"values": ["<normalized category>"]},
      "company_headcount_range": {"values": ["<user size range>"]},
      "company_country_code": {"values": ["<user geo>"]},
      "has_email": true
    }
  }' \
  --number-of-results 5 \
  --tool-reasoning '<user request verbatim>'

Note the session_id and table_name from the output — pass these to every subsequent step.

Run the full enrich chain on those 5 (Phase 2), show the result as a table, then ask: "Does this look right? How many prospects do you want in the full run?" Only after approval re-run at full scale.

Phase 2 — Enrich with Contact Info

Enrich the fetched prospects with verified work email, LinkedIn URL, and direct phone.

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npx @vibeprospecting/vpai@latest enrich-prospects --all-parameters

npx @vibeprospecting/vpai@latest enrich-prospects \
  --args '{"enrichments": ["contacts", "profiles"]}' \
  --session-id <SESSION_ID> \
  --table-name <TABLE_NAME_FROM_FETCH_STEP> \
  --tool-reasoning '<user request verbatim>' \
  --csv

Drop any prospects where work_email is empty — Lemlist requires a valid email to add a lead.

Output: prospects-enriched.csv — columns include first_name, last_name, work_email, linkedin_url, job_title, company_name, company_domain, employee_count, annual_revenue, tech_stack, last_funding_type

Phase 3 — Write Personalized Emails

Read prospects-enriched.csv and write a personalized email for each prospect using their actual company data. Do not use generic templates — each email should reference something specific to that company.

Ask the user for:

"What's the core value prop you want to lead with? And is there a specific pain point, use case, or trigger (e.g. recent funding, tech stack) you want to reference?"

For each prospect, write:

1. Icebreaker (1 sentence) — a specific, researched opening line referencing something real about their company. Examples of what to use:

• Their tech stack (e.g. "Noticed you're running Salesforce + HubSpot...")
• Company size/growth signal (e.g. "With [X] employees and growing...")
• Funding event (e.g. "Congrats on the Series B — scaling RevOps is usually top of mind at that stage...")
• Industry-specific angle

2. Email body — 4–6 sentences max. Structure:

• Icebreaker (from above)
• One-sentence value prop tied to their context
• One-sentence social proof or specific outcome
• Clear, low-friction CTA (e.g. "Worth a 15-min call this week?")

3. Subject line — short, specific, not salesy. Under 8 words.

Write all output to prospects-emails.csv, adding these columns to the enriched data:

Example output row:

After writing all emails, show a table of 3–5 sample rows for the user to review before uploading. Ask: "Does the tone and personalization feel right? Any tweaks before I push to Lemlist?"

Phase 4 — Create Lemlist Campaign

Create a new campaign in Lemlist to hold these prospects, or ask the user if they want to add to an existing one.

Option A — Create a new campaign

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# Create campaign
CAMPAIGN=$(curl -s -X POST "https://api.lemlist.com/api/campaigns" \
  -u ":$LEMLIST_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Vibe Prospecting — <ICP description> — <date>",
    "type": "email"
  }')

echo $CAMPAIGN | python3 -c "import json,sys; d=json.load(sys.stdin); print('Campaign ID:', d.get('_id','error'))"
export LEMLIST_CAMPAIGN_ID="<campaign _id from above>"

Option B — Use an existing campaign

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# List existing campaigns
curl -s "https://api.lemlist.com/api/campaigns" \
  -u ":$LEMLIST_API_KEY" \
  | python3 -c "
import json, sys
for c in json.load(sys.stdin):
    print(c['_id'], '—', c['name'])
"

# User picks one → set it
export LEMLIST_CAMPAIGN_ID="<chosen campaign id>"

Phase 5 — Upload Leads to Lemlist

Add each prospect from prospects-emails.csv to the campaign. Lemlist accepts custom variables per lead — use these to carry the personalized icebreaker and email copy into the campaign.

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import csv, json, os, requests, time

API_KEY = os.environ["LEMLIST_API_KEY"]
CAMPAIGN_ID = os.environ["LEMLIST_CAMPAIGN_ID"]
AUTH = ("", API_KEY)

with open("prospects-emails.csv") as f:
    prospects = list(csv.DictReader(f))

success, failed = 0, []

for p in prospects:
    email = p.get("work_email", "").strip()
    if not email:
        continue

    payload = {
        "firstName":    p.get("first_name", ""),
        "lastName":     p.get("last_name", ""),
        "companyName":  p.get("company_name", ""),
        "linkedinUrl":  p.get("linkedin_url", ""),
        # Custom variables — reference these in your Lemlist email template
        # as {{icebreaker}}, {{emailBody}}, {{emailSubject}}
        "icebreaker":   p.get("icebreaker", ""),
        "emailBody":    p.get("email_body", ""),
        "emailSubject": p.get("email_subject", ""),
    }

    resp = requests.post(
        f"https://api.lemlist.com/api/campaigns/{CAMPAIGN_ID}/leads/{email}",
        auth=AUTH,
        json=payload
    )

    if resp.status_code in (200, 201):
        success += 1
    elif resp.status_code == 429:
        print("Rate limited — waiting 5s")
        time.sleep(5)
        resp = requests.post(
            f"https://api.lemlist.com/api/campaigns/{CAMPAIGN_ID}/leads/{email}",
            auth=AUTH, json=payload
        )
        if resp.status_code in (200, 201):
            success += 1
        else:
            failed.append({"email": email, "error": resp.text})
    else:
        failed.append({"email": email, "error": resp.text})

print(f"\n✅ {success} leads uploaded")
if failed:
    print(f"❌ {len(failed)} failed:")
    for f in failed: print(" ", f["email"], "—", f["error"])

After upload, tell the user:

"[N] leads are now in your Lemlist campaign. Before you launch, make sure your email template in Lemlist uses {{icebreaker}}, {{emailBody}}, and {{emailSubject}} as variables so the personalization populates correctly. You'll also want to set your sending schedule and daily limits in Lemlist before activating."

Full Checklist

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[ ] Step 0  — Vibe Prospecting connected, Lemlist API key verified
[ ] Phase 1 — ICP defined, prospect list fetched (sample approved)
[ ] Phase 2 — Prospects enriched with verified emails and company data
[ ] Phase 3 — Personalized emails written and reviewed
[ ] Phase 4 — Lemlist campaign created or selected
[ ] Phase 5 — Leads uploaded with personalization variables
[ ] Done    — Review campaign in Lemlist, set schedule, activate

Lemlist Template Setup (one-time)

In your Lemlist campaign, your email step should use these variable placeholders:

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Subject: {{emailSubject}}

{{icebreaker}}

{{emailBody}}

This lets Claude's personalized copy flow directly into each lead's email without any manual editing.

Troubleshooting