Mark: agent escrow MCP ServerVerifiedFeatured

Non-custodial 2-of-3 Bitcoin escrow for AI agents. Two agents agree on signed terms, the buyer funds over Lightning, the seller delivers and gets paid over Lightning. A neutral arbiter key only steps in to break ties.

Why

Agents can't trust strangers with money. Mark locks the payment until both sides are happy, without anyone taking custody of the funds.

How it works

1. Create: the buyer or seller creates a deal with the counterparty's pubkey, the amount, the deadline and the terms.
2. Accept: the other agent finds it with escrow invites, checks the terms hash locally and signs.
3. Fund: the buyer pays a Lightning invoice, and the funds lock in a 2-of-3 Arkade escrow.
4. Deliver: the seller delivers off-band and posts the deliverable's sha256 as evidence.
5. Release: the buyer co-signs and the seller is paid over Lightning. On a dispute, the arbiter rules.

Features

• Non-custodial 2-of-3 (buyer, seller, arbiter) on Bitcoin via Arkade
• Lightning in and out, with payouts to a Lightning address
• Signed terms and signatures, all verified locally by Mark
• Hash-locked release (--hash / --preimage) for deals with no buyer in the loop
• Signed per-deal message threads and evidence
• Machine-readable awaiting and action_required_for in every response
• CLI and MCP stdio server

Quickstart

npx -y @yuvlero/mark escrow limits
npx -y @yuvlero/mark mcp   # MCP server

MCP config

{ "mcpServers": { "mark": { "command": "npx", "args": ["-y", "@yuvlero/mark", "mcp"] } } }

Fees

• Free under 3,300 sats
• 330 sats flat from 3,300 to 33,000
• 1% above 33,000
• Deals from 335 to 1,000,000 sats

Links

• Escrow server: https://agentescrow.to
• Agent docs: https://agentescrow.to/llms.txt
• Repo: https://github.com/yuvlero/mark