Docs · Recipes

Check leads with Precleared before your agent adds them to lemlist

If your AI agent runs lemlist through lemlist's MCP server, connect Precleared's MCP server next to it. Your agent checks each address first, adds only cleared leads to your campaigns and puts the rest on lemlist's unsubscribe list, so no campaign emails them by mistake.

What you need

• A Precleared key. Every new key starts with 14 days at 100 checks a day, then your own 100 a day over MCP, no card needed. Get a free key.
• lemlist's MCP server, which lemlist includes on every plan. It signs in with OAuth or takes your lemlist API key.

1. Connect both servers

In Claude Code:

claude mcp add --transport http precleared "https://precleared.dev/mcp?src=guide-lemlist" --header "Authorization: Bearer pc_live_..."
claude mcp add --transport http lemlist https://app.lemlist.com/mcp --header "X-API-Key: YOUR_LEMLIST_API_KEY"

In Claude.ai or the Claude desktop app, add each server under Settings, Connectors, Add custom connector: https://precleared.dev/mcp?src=guide-lemlist (or Precleared from the Claude directory), then https://app.lemlist.com/mcp, which signs you in to lemlist. For other clients, see Precleared's MCP setup and lemlist's.

2. Give your agent the rule

Paste this into your agent's instructions, a project's instructions or a skill:

Before adding a new lead to a lemlist campaign, call Precleared's contact_check once for its email address. Send address_source (where you got the address) and sender_country, plus company_name and pitch when you know them.
- ok_to_email: add the lead to the campaign and save the receipt id on it as a custom variable called precleared_receipt.
- consent_needed or blocked: don't add the lead. Add the address to lemlist's unsubscribe list (POST /api/v2/unsubscribes/variables/{email}, through lemlist's API tool) and note the next_step.
- unknown: don't add the lead yet. Supply the missing fact (recipient_country, default_recipient_country if all your prospects are in one country, or company_number), then check again.
Every email must meet footer_text: usually who you are, a postal address and a way to opt out.

What happens to each lead

Good to know

• lemlist's docs list a group of unsubscribe tools and a general call_api tool, but don't name each tool, so the rule gives the API route. Outside the agent, the same call is POST https://api.lemlist.com/api/v2/unsubscribes/variables/{value}, which takes an email or a domain, with your API key as the Basic auth password.
• lemlist retired its older /unsubscribes endpoints on 1 November 2026, so use the v2 route above.
• Prefer a workflow to an agent? The Clay, Make, Zapier and n8n recipes hand cleared leads to lemlist, and the lemlist guide calls its API directly.
• Tool names and settings come from lemlist's MCP docs as of 30 October 2026. If they change, your agent sees the new names in the server's tool list.
• The ?src=guide-lemlist tag on Precleared's address only tells us which guide you used. It doesn't change your allowance or your results.

Every check has a signed receipt. Open precleared.dev/r/ followed by its id to show a client why an email went out.

Decision support with sources, not legal advice.