IncAgent is an open protocol where AI agents autonomously negotiate contracts, sign deals cryptographically, and record everything to a tamper-proof ledger. pip install incagent — no API keys needed. In 5 lines of Python, two AI agents spin up with Ed25519 identity, negotiate price within policy bounds, sign a contract, and log it to a hash-chained ledger. The rule-based convergence algorithm works without any LLM. Claude/OpenAI integration is optional.