Sieve MCP Server

March 5, 2026 · View on GitHub

Sieve MCP Server — AI-Powered Venture Capital Due Diligence

The first MCP server purpose-built for venture capital. Drop a company name into Claude, Cursor, or Windsurf and get a quantified investment memo in 5 minutes — not a ChatGPT summary, a real analyst-grade IMPACT-X assessment with every claim verified against evidence.

"Screen a startup called Acme Corp" → Sieve researches the company, scores it across 7 dimensions, verifies every claim, and tells you: Take the meeting or Pass.

Why Sieve?

Most VCs screen 50+ deals a month. Most of those are obvious passes — but you still spend 2-3 hours per deal on basic diligence before you know that. Sieve does that work in 5 minutes.

What You Get

Capability	Details
Investment Memo	Full analyst-grade memo with executive summary, key strengths, critical concerns, and actionable recommendation — not a ChatGPT summary
Deal Scoring (0-140)	Quantified Sieve Score across 7 IMPACT-X dimensions — structured, repeatable, comparable across your portfolio
Red Flag Detection	Automatically surfaces deal-breakers: founder risk, market timing issues, unsustainable unit economics, missing traction, competitive threats
Evidence Verification	Every finding tagged as Documented, Discovered, Inferred, or Missing — cross-references pitch deck claims against real-world evidence
Competitive Landscape	Maps competitors, identifies moat strength, evaluates defensibility and switching costs
Financial Model Assessment	Evaluates unit economics, pricing power, revenue model viability, and path to profitability
Market Sizing	TAM/SAM/SOM analysis with timing assessment — is the market ready?
Team Evaluation	Founder-market fit, team completeness, domain expertise, execution track record
Traction Analysis	Growth metrics, customer validation, revenue signals, engagement patterns
Real-time Deal Chat	Ask follow-up questions, challenge findings, explore what-if scenarios, dig into any dimension
Sector-Aware Analysis	Adapts benchmarks for fintech, healthtech, deeptech, climate, SaaS, consumer, and more
Stage-Calibrated	Different expectations for pre-seed vs seed vs Series A — doesn't penalize early-stage for missing late-stage metrics

What Makes Sieve Different

Not a wrapper around ChatGPT. Sieve runs a structured multi-agent analysis pipeline with real-time web research, evidence verification, and domain-specific benchmarks.
We tell you what we don't know. Every finding is evidence-typed (Documented / Discovered / Inferred / Missing) so you see exactly what's verified and where the gaps are.
Repeatable framework. The same IMPACT-X methodology every time, so you can compare deals apples-to-apples across your portfolio.
Built by VCs. Not a generic AI tool adapted for investing — purpose-built for the way investors actually evaluate deals.

IMPACT-X Framework

Dimension	What Sieve evaluates
I — Innovators	Founding team quality, experience, domain expertise
M — Market	Opportunity size, timing, tailwinds
P — Product	Solution strength, differentiation, technical depth
A — Advantage	Competitive moat, defensibility, switching costs
C — Commerce	Business model, unit economics, pricing power
T — Traction	Growth metrics, validation signals, customer evidence
X — X-Factor	Unique qualities, timing advantages, intangibles

Each dimension scores 0-20. Total Sieve Score ranges from 0-140.

Quick Start

Install

pip install sieve-mcp

Or run directly without installing:

uvx sieve-mcp

Get Your API Key

Sign up free at app.sieve.arceusxventures.com
Go to Settings → copy your API key
Free tier: 2 screens/month. Pro: unlimited.

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "sieve": {
      "command": "uvx",
      "args": ["sieve-mcp"],
      "env": {
        "SIEVE_API_KEY": "your-api-key"
      }
    }
  }
}

Claude Code

claude mcp add sieve -- uvx sieve-mcp
export SIEVE_API_KEY="your-api-key"

Cursor / Windsurf

Add to your MCP settings:

{
  "mcpServers": {
    "sieve": {
      "command": "uvx",
      "args": ["sieve-mcp"],
      "env": {
        "SIEVE_API_KEY": "your-api-key"
      }
    }
  }
}

Available Tools

Tool	What it does	Read-only
`sieve_screen`	Start a Quick Screen — pass a company name, optional website URL, pitch deck text, or description	No
`sieve_status`	Poll analysis progress — see which dimensions are complete and current scores	Yes
`sieve_summary`	Get the full investment memo — Sieve Score, recommendation, strengths, concerns, evidence	Yes
`sieve_usage`	Check how many screens you've used this billing period	Yes

Example Workflow

Just talk to your AI assistant naturally:

1. Screen a startup

"Run a Sieve screen on Acme Corp at acme.com"

2. Check progress (analysis takes 2-5 minutes)

"What's the status of that Sieve analysis?"

3. Get the full investment memo

"Show me the Sieve results for Acme Corp"

4. Explore the deal

"What are the red flags? Anything that should kill this deal?"

"How strong is their competitive moat? Who are the main competitors?"

"Walk me through their unit economics — is this business model viable?"

"How does the founding team stack up? Any gaps?"

"What's the market timing like? Is this too early or too late?"

"Compare this deal to the last three I screened"

5. Check your usage

"How many Sieve screens do I have left this month?"

Pro tip: Upload a pitch deck for deeper analysis

Paste pitch deck text or founder meeting notes for maximum accuracy:

"Screen Acme Corp — here's their pitch deck text: [paste]. Also check acme.com"

Sieve cross-references every pitch deck claim against real-world evidence. When a founder says "fastest-growing in the category," Sieve checks if that's actually true.

More things you can ask

Use case	Example prompt
Quick pass/take meeting	"Screen this company and give me the bottom line"
Investment memo for IC	"Generate a full investment memo I can present to my partners"
Red flag check	"What are the deal-breakers for this startup?"
Competitive analysis	"Who competes with this company and how defensible are they?"
Financial viability	"Does their business model make sense? What are the unit economics?"
Team assessment	"Evaluate the founding team — any gaps or concerns?"
Market validation	"Is the market real? What's the TAM and timing?"
Batch screening	"Screen these 5 startups and rank them by Sieve Score"
Follow-up prep	"Based on this analysis, what questions should I ask the founders?"
Portfolio comparison	"How does this deal compare to others I've screened?"

Who Uses Sieve

Solo GPs screening 50+ deals/month — stop spending hours on obvious passes
Angel investors evaluating startups outside their domain — Sieve brings sector expertise
Emerging fund managers building a repeatable diligence process — consistent framework, every time
Accelerators standardizing evaluation — compare apples to apples across your cohort

Environment Variables

Variable	Required	Default	Description
`SIEVE_API_KEY`	Yes	—	Your Sieve API key (get one free)
`SIEVE_API_URL`	No	`https://api.sieve.arceusxventures.com`	API base URL

Running with Docker

docker build -t sieve-mcp .
docker run -p 8080:8080 -e SIEVE_API_KEY=your-key sieve-mcp

Development

# Install locally
pip install -e .

# Run in stdio mode (for MCP clients)
sieve-mcp

# Run in HTTP mode (for remote/container deployment)
sieve-mcp http

Also Available As

Sieve isn't just an MCP server. Use it however fits your workflow:

Web App — app.sieve.arceusxventures.com — Full experience with real-time deal chat and document upload
REST API — api.sieve.arceusxventures.com/api/docs — Integrate into custom deal flow pipelines
Android App — Screen startups on the go

License

MIT

Built by ArceusX Ventures — from VCs, for VCs.