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Environment Setup

GTM Skills integrates with multiple APIs. This guide shows you how to set up credentials and manage environment variables.

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Required: Extruct API Token

The Extruct API token is the only credential you must set upfront. All other provider credentials are requested in-chat when the corresponding skill runs.

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Get Your Token

  1. Sign up at extruct.ai
  2. Navigate to Settings → API Keys
  3. Generate a new API token
  4. Copy the token (starts with ext_)

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Set the Token

Option A: Export in your shell 
export EXTRUCT_API_TOKEN=ext_your_token_here
Add to your ~/.bashrc, ~/.zshrc, or equivalent to persist across sessions. Option B: Add to Claude Code environment If using Claude Code, add to your project’s environment file: 
echo "EXTRUCT_API_TOKEN=ext_your_token_here" >> .env

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Verify

test -n "$EXTRUCT_API_TOKEN" && echo "Extruct token set" || echo "Extruct token missing"
You should see: Extruct token set

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Optional: Contact Enrichment Providers

These are requested when you run the email-search skill. You can set them upfront or provide them in-chat.

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Prospeo

Use case: LinkedIn → verified email enrichment
  1. Sign up at prospeo.io
  2. Get API key from dashboard
  3. Set token: 
    export PROSPEO_API_KEY=your_key_here
Pricing: Pay-per-match, typically $0.10-0.20 per verified email

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Fullenrich

Use case: Waterfall enrichment (multiple data sources)
  1. Sign up at fullenrich.com
  2. Get API key from dashboard
  3. Set token: 
    export FULLENRICH_API_KEY=your_key_here
Pricing: Credit-based, ~1-2 credits per enrichment

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Optional: Email Sequencing Providers

These are requested when you run the campaign-sending skill.

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Instantly

Use case: Email sequencing and sending
  1. Sign up at instantly.ai
  2. Navigate to Settings → Integrations → API
  3. Generate API key
  4. Set token: 
    export INSTANTLY_API_KEY=your_key_here
What you need:
  • API key
  • Workspace ID (found in URL: app.instantly.ai/app/{workspace_id})
  • At least 1 email account connected and warmed

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Smartlead

Use case: Alternative to Instantly
  1. Sign up at smartlead.ai
  2. Get API key from Settings
  3. Set token: 
    export SMARTLEAD_API_KEY=your_key_here

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Lemlist

Use case: Alternative to Instantly
  1. Sign up at lemlist.com
  2. Get API key from Settings → Integrations
  3. Set token: 
    export LEMLIST_API_KEY=your_key_here

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Environment Variables Summary

VariableServiceUsed ByRequired?
EXTRUCT_API_TOKENExtruct APIlist-building, list-enrichment, table-creation, people-search, list-segmentation, email-searchYes
PROSPEO_API_KEYProspeoemail-searchNo (requested in-chat)
FULLENRICH_API_KEYFullenrichemail-searchNo (requested in-chat)
INSTANTLY_API_KEYInstantlycampaign-sendingNo (requested in-chat)
SMARTLEAD_API_KEYSmartleadcampaign-sendingNo (requested in-chat)
LEMLIST_API_KEYLemlistcampaign-sendingNo (requested in-chat)

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Multi-Provider Strategy

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Email Enrichment: Waterfall

For maximum hit rate, use multiple providers in sequence:
  1. Run Prospeo first (fast, good LinkedIn coverage)
  2. Collect misses (contacts with no email found)
  3. Run Fullenrich on misses (waterfall, slower but broader coverage)
Typical results:
  • Prospeo alone: 60-70% hit rate
  • Prospeo + Fullenrich waterfall: 75-85% hit rate

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Email Sequencing: Test Before Committing

Instantly, Smartlead, and Lemlist have similar features. Pick based on:
FactorInstantlySmartleadLemlist
PricingPer send ($)Per lead ($$)Per send ($)
WarmupBuilt-inBuilt-inBuilt-in
APIWell-documentedGoodBasic
DeliverabilityHighHighMedium
Run a 50-contact test campaign on each before scaling.

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Credential Security

Never commit API keys to version control. Use environment variables or secret managers.

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Best Practices

  1. Use environment variables, not hardcoded keys
  2. Rotate keys quarterly or after team member changes
  3. Scope permissions - create API keys with minimal required access
  4. Monitor usage - set up billing alerts on provider dashboards

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.env File Template

Create a .env file in your project root: 
# Extruct (required)
EXTRUCT_API_TOKEN=ext_your_token_here

# Contact Enrichment (optional, requested in-chat)
PROSPEO_API_KEY=your_prospeo_key
FULLENRICH_API_KEY=your_fullenrich_key

# Email Sequencing (optional, requested in-chat)
INSTANTLY_API_KEY=your_instantly_key
# SMARTLEAD_API_KEY=your_smartlead_key
# LEMLIST_API_KEY=your_lemlist_key
Add .env to .gitignore: 
echo ".env" >> .gitignore

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Loading Environment Variables

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In Shell Sessions

source .env

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In Claude Code

Claude Code auto-loads .env files in your project root.

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Verify All Variables

env | grep -E '(EXTRUCT|PROSPEO|FULLENRICH|INSTANTLY|SMARTLEAD|LEMLIST)'

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API Rate Limits

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Extruct

  • Search API: Unlimited requests, free
  • Discovery API: 1 task at a time, 250 results max per task
  • Enrichment API: 50 concurrent cells, 1 credit per cell
  • People Finder: 2 credits per person found
Tip: For large enrichments (1000+ cells), Extruct auto-throttles. Expect 5-10 min for 200 companies × 3 columns.

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Prospeo

  • Email Finder: 60 requests/min
  • Bulk Enrichment: 100 contacts/batch, 10 batches/min
Tip: For 500 contacts, expect 5-10 minutes.

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Instantly

  • API: 100 requests/min
  • Lead Upload: 1000 leads/batch
Tip: For 1000 leads, upload takes 1-2 minutes.

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Cost Estimation

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Example Campaign: 300 Companies

StepServiceCost
List BuildingExtruct SearchFree
Enrichment (3 columns)Extruct (300 × 3 = 900 credits)53(at53 (at 59/1K credits)
People Search (3 per company)Extruct (900 × 2 = 1800 credits)$106
Email Enrichment (900 contacts)Prospeo (900 × $0.15)$135
Email Sequencing (800 sends)Instantly (800 × $0.10)$80
Total$374
Breakdown:
  • Extruct: $159 (2700 credits)
  • Prospeo: $135 (900 contacts)
  • Instantly: $80 (800 sends)

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First Campaign (Smaller)

For your first campaign, run 100 companies to test:
StepServiceCost
List BuildingExtruct SearchFree
Enrichment (3 columns)Extruct (300 credits)$18
People Search (2 per company)Extruct (200 × 2 = 400 credits)$24
Email Enrichment (200 contacts)Prospeo (200 × $0.15)$30
Email Sequencing (150 sends)Instantly (150 × $0.10)$15
Total$87
Extruct’s free trial (100 credits) covers list enrichment. You’ll pay for people search, email enrichment, and sending.

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Monitoring Usage

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Extruct Dashboard

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Prospeo Dashboard

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Instantly Dashboard

  • Navigate to instantly.ai
  • View campaign stats and sending usage

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Troubleshooting

Error: EXTRUCT_API_TOKEN not set
  • Run: export EXTRUCT_API_TOKEN=your_token
  • Verify: echo $EXTRUCT_API_TOKEN
Error: Invalid Extruct token
  • Check token format (starts with ext_)
  • Regenerate token in Extruct dashboard
  • Verify no extra whitespace: echo "$EXTRUCT_API_TOKEN" | wc -c
Error: Prospeo rate limit
  • Reduce batch size from 100 to 50
  • Add delay between batches (2-3 seconds)
Error: Instantly authentication failed
  • Verify API key + workspace ID
  • Check API key permissions (needs campaign write access)

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Next Steps

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