Kaginet — Trustless Bitcoin Escrow for AI Agents

Hardware-attested Bitcoin escrow that AI agents can use via MCP, LangChain, or CrewAI. No custody, no trust assumptions, no counterparty risk.

Live on Bitcoin mainnet. Running inside an Intel TDX confidential VM.

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Why Kaginet

Property	How
No custody	Mathematical lockout: the issuer key is destroyed before funding. Bitcoin consensus enforces this, not policy.
Private	Off-chain bearer transfers are invisible. No public ledger for intermediate transfers.
Hardware-attested	Intel TDX proves the code that deleted the key is the audited code. Verifiable against Intel's root CA.
29 MCP tools	Any MCP-compatible agent (Claude, GPT-4, Cursor, Windsurf) gets payment capability with one URL.
Bitcoin mainnet	Real money. Live now. Not a testnet demo.

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Quick Start

Option A: MCP (recommended, zero install)

Add to your Claude Desktop, Cursor, or Windsurf MCP config:

{
  "mcpServers": {
    "kagikai": {
      "url": "https://mcp.kaginet.com/sse",
      "headers": {
        "Authorization": "Bearer kagi_YOUR_API_KEY"
      }
    }
  }
}

Get an API key at cloud.kaginet.com.

Your agent now has 29 payment tools. Try:

Create a 50,000 sat escrow to bc1q...recipient for "Logo design work"

Option B: LangChain

pip install kagikai-langchain

from kagikai_langchain import KagikaiToolkit

toolkit = KagikaiToolkit(
    base_url="https://mcp.kaginet.com",
    api_key="kagi_YOUR_API_KEY",
)
tools = toolkit.get_tools()  # 29 tools ready for your agent

Option C: CrewAI

pip install kagikai-crewai

from kagikai_crewai import (
    KagikaiEscrowCreateTool,
    KagikaiEscrowStatusTool,
    KagikaiEscrowReleaseTool,
)

# Add to your crew's agent
tools = [
    KagikaiEscrowCreateTool(),
    KagikaiEscrowStatusTool(),
    KagikaiEscrowReleaseTool(),
]

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How It Works

Agent Runtime                MCP Server              ICS (TEE Enclave)           Bitcoin
─────────────                ──────────              ─────────────────           ───────
                                                                                    
  kagikai_escrow_create ──▶  Authenticate ──▶  Generate keys inside TDX            
                                               Destroy issuer key (kA)             
                                               Create P2TR escrow address          
                                               Generate bc1q funding addr          
                             ◀── instrument_id + funding_address ◀──               
                                                                                    
  "Fund this address" ────────────────────────────────────────────────▶ bc1q funded
                                                                                    
                                               Watcher detects funding             
                                               Auto-forward bc1q → bc1p    ──────▶ P2TR escrow
                                               Status: Confirmed                   
                                                                                    
  kagikai_escrow_release ─▶  Sign JWT ──────▶  Evaluate evidence                   
                                               Status: Completed                   
                                               Auto-sweep to payee         ──────▶ Payee receives
                                               Zero all keys                       

1. Create: Agent calls kagikai_escrow_create with amount and payee address. ICS generates keys inside the TEE, destroys the issuer key, returns a bc1q funding address.
2. Fund: Payer sends bitcoin to the bc1q address from any wallet. ICS auto-forwards to the internal P2TR escrow.
3. Release: Agent submits evidence. Evaluator validates (auto or manual). ICS auto-sweeps funds to the payee.
4. Attest: At any point, anyone can verify the TDX attestation proving the issuer key was deleted by the audited code.

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Instrument Lifecycle

Created ──▶ WatchingForFunding ──▶ Forwarding ──▶ Confirmed
                                                      │
                                    ┌─────────────────┤
                                    ▼                  ▼
                                Submitted          Expired
                                    │                  │
                       ┌────────────┼────────────┐     ▼
                       ▼            ▼            ▼  Available
                  Completed    Rejected    DisputeWindow  │
                       │            │            │        ├──▶ Recycled ──▶ Confirmed
                       ▼            ▼            │        └──▶ Refunded (terminal)
                    Swept       Available    ┌───┴───┐
                  (terminal)        │        ▼       ▼
                                    │   Completed  Disputed
                                    │  (auto-win)     │
                                    │            ┌────┴────┐
                                    │            ▼         ▼
                                    │       Completed  Rejected
                                    │      (seller     (buyer
                                    │       wins)       wins)
                                    ▼
                              Recycled / Refunded

Full state machine documentation: docs/instrument-lifecycle.md

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Documentation

Document	Description
Architecture	System components, trust boundaries, data flow
Instrument Lifecycle	State machine with all transitions
API Reference	Every REST endpoint with schemas
MCP Tools	All 29 tool definitions
Attestation	TDX attestation chain and verification
Dispute Mechanism	Optimistic settlement with bonds
Fee Model	Fee structure and estimation
Security Model	Threat model and trust boundaries
Comparison	Kaginet vs ERC-8183 vs Stripe vs AURA
Protocol Specification	Full escrow protocol: state machine, evaluator schemas, Nostr events, MCP tools

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Live Endpoints

Endpoint	URL
MCP (SSE)	https://mcp.kaginet.com/sse
Developer Dashboard	cloud.kaginet.com
Product Website	kaginet.com

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Examples

• quickstart.py — Create your first escrow
• agent-escrow-flow.py — Full agent-to-agent payment
• mcp-config.json — MCP client configuration
• langchain-agent.py — LangChain agent with payment tools
• crewai-crew.py — CrewAI crew with escrow capability
• verify-attestation.py — Verify a TDX attestation
• fee-estimate.py — Check fees before creating an escrow

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Project Structure

kaginet/
  adapters/
    langchain/          # pip install kagikai-langchain (29 tools)
    crewai/             # pip install kagikai-crewai (29 tools)
    tests/              # 90 adapter tests
  docs/                 # Architecture, API reference, protocol docs
  examples/             # Integration examples
  verify/               # TDX attestation verification tool

The ICS server (Rust, runs inside Intel TDX) is not included in this repository. This repo contains the integration layer: framework adapters, documentation, and examples.

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Security

See SECURITY.md for our responsible disclosure policy.

The security model is documented at docs/security-model.md.

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Contributing

See CONTRIBUTING.md. We welcome adapter contributions for new frameworks, documentation improvements, and example code.

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License

See LICENSE. License terms are currently under evaluation.