SigAid - Secure Agent Identity Protocol

A cryptographically secure agent identity protocol with exclusive leasing, state continuity, and verification capabilities.

Features

• Cryptographic Identity: Ed25519-based agent identities with checksums
• Exclusive Leasing: Prevents "clone" attacks - only one instance per agent
• State Chain: Hash-linked action log for verifiable history
• Proof Bundles: Cryptographic proofs for service verification
• Framework Integrations: One-line wrapping for LangChain, CrewAI, AutoGen

Installation

pip install sigaid

For framework integrations:

pip install sigaid[langchain]   # LangChain support
pip install sigaid[crewai]      # CrewAI support
pip install sigaid[autogen]     # AutoGen support
pip install sigaid[all-integrations]  # All frameworks

Quick Start

One-Line Framework Integration

import sigaid

# Wrap your existing agent - that's it!
agent = sigaid.wrap(my_langchain_agent)

# Use exactly as before
result = agent.invoke({"input": "Hello"})

# Agent now has verifiable identity
print(agent._sigaid.agent_id)

Direct SDK Usage

import asyncio
from sigaid import AgentClient

async def main():
    # Create new agent
    client = AgentClient.create()
    print(f"Agent ID: {client.agent_id}")
    
    # Acquire exclusive lease
    async with client.lease() as lease:
        # Record actions
        await client.record_action(
            "transaction",
            {"amount": 100, "recipient": "merchant_123"},
            summary="Processed payment"
        )
        
        # Create proof for verification
        proof = client.create_proof(challenge=b"verifier_nonce")
    
    await client.close()

asyncio.run(main())

Service-Side Verification

from sigaid import Verifier

verifier = Verifier(api_key="...")

result = await verifier.verify(
    proof_bundle,
    require_lease=True,
    min_reputation_score=0.7,
)

if result.valid:
    print(f"Agent {result.agent_id} verified!")

Core Concepts

Agent Identity

Each agent has a unique cryptographic identity:

• AgentID: Derived from Ed25519 public key (aid_7Xq9YkPz...)
• KeyPair: Used for signing actions and proofs
• Stored in encrypted keyfiles for persistence

Exclusive Leasing

Prevents "clone" attacks where multiple instances use the same identity:

• Only one instance can hold a lease at a time
• Atomic acquisition via Authority service
• Automatic renewal while in use
• Clone attempts are rejected

State Chain

Tamper-evident log of agent actions:

• Hash-linked entries (BLAKE3)
• Signed with Ed25519
• Fork detection for clone prevention
• Verifiable by services

Proof Bundles

Complete proof for verification:

• Agent identity
• Active lease
• State chain head
• Challenge-response signature

Security

Framework Support

Environment Variables

SIGAID_API_KEY=sk_live_xxx     # API key for Authority
SIGAID_AUTHORITY_URL=https://api.sigaid.com  # Authority URL
SIGAID_LOG_LEVEL=INFO          # Logging verbosity

Development

# Install dev dependencies
pip install -e ".[dev]"

# Run tests
pytest tests/ -v

# Type checking
mypy sigaid/

# Linting
ruff check sigaid/

License

MIT License