@arbitova/mcp-server

**Non-custodial USDC escrow + AI arbitration for agent-to-agent payments on Base.**
Two agents lock USDC into a contract, one delivers, the other confirms or disputes, and a neutral AI arbiter resolves. Arbitova never holds the money — the contract does.
No API keys. No registration. No custody. Your Ethereum address is your identity.
- Contract: EscrowV1 at 0xA8a031bcaD2f840b451c19db8e43CEAF86a088fC on Base Sepolia — verified on Basescan, mainnet launching after audit
- Spec: A2A-ESCROW-RFC-v0.1
- Machine-readable descriptor: /.well-known/arbitova.json
- Per-case verdict dashboard: arbitova.com/verdicts
- Integration paths: arbitova.com/integrate (raw contract / reference SDKs / agent-native)
- Reference UI (non-canonical, for humans): arbitova.com/pay
- 15-minute tutorial: docs/tutorials/15-min-paid-agent.md
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Why this exists
Every A2A / agent-commerce spec in the wild — MCP, Google's A2A, ERC-7683, Coinbase's Agent Commerce — defines *how agents talk*. None of them define *how money moves when the agents don't trust each other*.
Arbitova is the missing settlement primitive:
- **Deterministic state machine.** createEscrow → markDelivered → {confirmDelivery | dispute → resolve | cancel}. No hidden branches, no admin override.
- **No auto-release after timeout.** Review windows expire into DISPUTED, not into seller payout. Silence is safer than a wrong confirmation.
- **Content-hash pinned on-chain.** Sellers can't swap the delivery file after the buyer inspects.
- **Per-case verdict transparency.** Every arbiter decision is a signed JSON blob; its keccak256 is stored on-chain. The full verdict history is queryable at /verdicts — no aggregation, no delay.
This is not a marketplace. There is no Arbitova account, no listing fee, no Pro tier. The protocol is the whole product.
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Quick start — Node.js SDK
Seller-side, arbiter-side, browser wallet integration: see packages/sdk-js/README.md.
Quick start — Python SDK
Quick start — Claude / any MCP client
Six tools: arbitova_create_escrow, arbitova_mark_delivered, arbitova_confirm_delivery, arbitova_dispute, arbitova_cancel_if_not_delivered, arbitova_get_escrow. All sign locally via ethers v6. Your private key never leaves the process.
Omit ARBITOVA_AGENT_PRIVATE_KEY for read-only introspection mode (useful for observability).
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Lifecycle
Two terminal states not drawn: CANCELLED (buyer calls cancelIfNotDelivered after delivery window) and auto-escalation into DISPUTED if the review window expires without confirmation.
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Framework reference agents
Three end-to-end A2A demos on Base Sepolia with a live AI arbiter:
- **Claude Agent SDK** — in-process MCP tools
- **LangGraph** — ReAct agent, buyer + seller + arbiter
- **CrewAI** — Agent + Task + Crew
Each demo runs the full CREATED → DELIVERED → CONFIRMED (or DISPUTED → RESOLVED) flow with real on-chain transactions.
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Packages
| Package | Purpose |
|---|---|
| @arbitova/sdk | Node.js / browser SDK (ethers v6) |