LeadsClean
FreeNot checkedExtracts structured B2B lead intelligence from company websites with buying signals, inferred needs, and personalized icebreaker lines.
About
Extracts structured B2B lead intelligence from company websites with buying signals, inferred needs, and personalized icebreaker lines.
README
An open-source MCP server that extracts structured B2B lead intelligence from company websites. Point it at any URL — get back a clean JSON object with company summary, buying signals, inferred needs, and personalised icebreaker lines.
Built as a reference implementation for MCP tool development. Demonstrates multi-provider LLM routing, dual-transport MCP serving, GDPR compliance patterns, and API key management — patterns you can reuse in your own MCP servers.
Works with Claude Desktop, Cursor, and any MCP-compatible client.
Tools
| Tool | Description |
|---|---|
extract_lead_intelligence |
Analyse a single company URL and return structured lead intel |
batch_extract_leads |
Analyse up to 20 URLs in parallel — designed for agent list-processing |
Output schema
{
"company_name": "Acme Hotels Group",
"core_business_summary": "Boutique hotel chain with 12 properties across Europe.",
"product_category_match": "Strong match — hotel groups purchase furniture in bulk for room refits.",
"recent_company_trigger": "Announced expansion to 3 new cities in Q1 2026, adding 400+ rooms.",
"inferred_business_need": "Bulk furnishing for new hotel rooms on tight fit-out timelines.",
"icebreaker_hook_business": "Running 12 properties across Europe is impressive — furnishing them at scale is where we help.",
"icebreaker_hook_news": "Saw the Q1 expansion news — we help hotel groups source wholesale beds and sofas fast.",
"data_provenance": {
"source_url": "https://acmehotels.com",
"source_type": "public_website",
"collection_method": "jina_reader_public_fetch",
"contains_pii": false,
"gdpr_basis": "legitimate_interest",
"gdpr_notes": "Extracted solely from publicly available company web pages. No personal data collected. Compliant with GDPR Art. 6(1)(f)."
}
}
Every response includes data_provenance — a machine-readable GDPR metadata block indicating data source, PII status, and legal basis.
Quick start
Prerequisites
- Python 3.11+
- An API key for at least one supported LLM provider (see Environment variables below)
Install
pip install mcp-leadsclean
Or clone and install from source:
git clone https://github.com/edition/leadsclean
cd leadsclean
pip install -e .
Claude Desktop
Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):
{
"mcpServers": {
"leadsclean": {
"command": "mcp-leadsclean",
"env": {
"OPENAI_API_KEY": "sk-..."
}
}
}
}
Set the key for whichever provider(s) you use (see Environment variables).
Cursor
Add to your Cursor MCP config (~/.cursor/mcp.json):
{
"mcpServers": {
"leadsclean": {
"command": "mcp-leadsclean",
"env": {
"OPENAI_API_KEY": "sk-..."
}
}
}
}
HTTP transport (production agent pipelines)
For remote agents or multi-tenant deployments, run with Streamable HTTP transport:
OPENAI_API_KEY=sk-... mcp-leadsclean --transport http --port 8001
The server exposes a single MCP endpoint at http://localhost:8001/mcp.
Demo mode
Try the server without an API key — useful for testing your agent pipeline or reviewing the output schema:
LEADSCLEAN_DEMO=1 mcp-leadsclean
All tool calls return a sanitised fixture response when LEADSCLEAN_DEMO=1 is set. The response includes "_demo": true so agents can detect and discard it.
Environment variables
The model parameter controls which provider is used. Provider is inferred from the model-name prefix — set the corresponding key:
| Variable | Required when | Model prefix | Description |
|---|---|---|---|
OPENAI_API_KEY |
Using OpenAI (default) | gpt-*, o1-*, o3-* |
OpenAI API key |
ANTHROPIC_API_KEY |
Using Claude | claude-* |
Anthropic API key |
DASHSCOPE_API_KEY |
Using Alibaba Qwen | qwen-* |
Alibaba DashScope API key |
MINIMAX_API_KEY |
Using MiniMax | abab*, minimax-* |
MiniMax API key |
LEADSCLEAN_DEMO |
— | — | Set to 1 to return fixture data without any LLM call |
The default model is gpt-4o-mini (OpenAI). To switch provider, pass the desired model ID in the tool call — e.g. claude-3-5-haiku-20241022 for Anthropic, qwen-turbo for Alibaba.
REST API
A standard FastAPI REST endpoint is also available for non-MCP integrations:
uvicorn main:app --reload
curl -X POST http://localhost:8000/extract-leads \
-H "Content-Type: application/json" \
-d '{
"target_url": "https://acmecorp.com",
"seller_context": "We provide cloud HR software to mid-size logistics companies."
}'
Reusable patterns
This project demonstrates several patterns worth extracting for your own MCP servers:
| Pattern | Where | What it does |
|---|---|---|
| Multi-provider LLM routing | core.py |
Dispatches to OpenAI / Anthropic / Qwen / MiniMax based on model name prefix |
| Dual-transport MCP serving | mcp_server.py |
Same tool logic served over stdio (local) and HTTP (remote) |
| SSRF protection | core.py |
Validates URLs against private IP ranges before external fetch |
| Prompt injection mitigation | core.py |
XML boundary tags around user-controlled content in LLM prompts |
| API key hashing | db.py |
SHA-256 hashing with prefix display — keys are never stored in plain text |
| Usage metering | db.py + auth.py |
Per-key monthly quotas with auto-reset and atomic increment |
| GDPR provenance | core.py |
Machine-readable compliance metadata on every response |
| Demo mode | core.py + auth.py |
Full bypass of external services for pipeline testing |
Development
# Install dependencies
pip install -r requirements.txt
# Run MCP server (stdio)
python mcp_server.py
# Run MCP server (HTTP, port 8001)
python mcp_server.py --transport http
# Run REST API
uvicorn main:app --reload
How it works
- Fetch — retrieves clean Markdown from the target URL via Jina Reader
- Extract — passes the content to your chosen LLM (OpenAI, Anthropic Claude, Alibaba Qwen, or MiniMax) with a structured prompt
- Return — outputs a JSON object matching the schema above
Content never leaves the pipeline: no data is stored by LeadsClean.
Built with Claude
This project was developed with the assistance of Claude by Anthropic — an AI assistant used for code generation, architecture design, and documentation.
License
MIT
Installing LeadsClean
This server has no published package — it is built from source. Open the repository and follow its README.
▸ github.com/edition/leadscleanFAQ
Is LeadsClean MCP free?
Yes, LeadsClean MCP is free — one-click install via Unyly at no cost.
Does LeadsClean need an API key?
No, LeadsClean runs without API keys or environment variables.
Is LeadsClean hosted or self-hosted?
Self-hosted: the server runs locally on your machine via the install command above.
How do I install LeadsClean in Claude Desktop, Claude Code or Cursor?
Open LeadsClean on unyly.org, pick your client tab (Claude Desktop, Claude Code, Cursor) and press Install — the config is generated automatically, no JSON editing.
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