Tools
Things built at the intersection — systems, agents — then opened and given back. Free where they can be; honest about what they do.
A coordination layer for multi-agent AI systems. Agents converge on a passive append-only shared blackboard — they leave traces, never overwrite each other's state — so multi-agent work stays auditable and debuggable, self-terminates instead of looping, and carries minimal context (≈ half the tokens in a measured A/B). It is the shared-state layer A2A and MCP leave to you. An optional on-chain layer is live on Celo mainnet: ERC-8004 agent identity + verifiable coordination receipts. When agents pay each other automatically (x402, AP2), Cairn is the coordination and verifiable-receipt layer around those payments — auditable runs tied to on-chain receipts, with an optional Celo stablecoin (cUSD/USDC) payment adapter. It complements payment protocols; it is not one.
pip install cairn-coordinationAn open-source agent-discovery toolkit — a way for agents (and the people behind them) to discover one another across the open web. A sibling of Cairn, same commons philosophy: built for a real need, then given back.
About these tools
These are open-source tools made by Tağmaç Çankaya at Casa Caravan (Lefkoşa, Cyprus). Each is built to solve a real problem, then given back as a commons — used, not just described.
Cairn addresses a recurring failure in multi-agent systems: when several agents write to shared state, last-write-wins silently overwrites work and the failure is hard to debug. Cairn replaces the shared conversation with a passive append-only blackboard and minimal per-agent context, so nothing is overwritten and every contribution is a durable, attributable trace. It is framework-agnostic (LangChain, LangGraph, CrewAI), measured (~54% fewer tokens in a controlled A/B), and carries an optional verifiable on-chain layer built on the ERC-8004 standard. As autonomous agents begin paying each other (x402, AP2, Bedrock AgentCore Payments), Cairn becomes the coordination and audit layer around those payments — the coordinated work and its payment captured as one verifiable on-chain receipt, with an optional Celo stablecoin (cUSD/USDC) adapter; it complements payment protocols rather than replacing them. Echo is an AGPLv3 agent-discovery toolkit, a sibling project.
If a tool here solves your problem, take it. If you want to go further than it can, the door is open.