Z-ZERO MCP — Payment Infrastructure for Agentic Commerce (USDC on Base, gasless)

AI Agents today can plan, reason, and code — but they are financially blind. They cannot hold money, make payments, or prove their trustworthiness. Every purchase still requires a human to copy-paste a credit card number.

Z-ZERO fixes that. One MCP server gives your agent (Claude, Cursor, any MCP-compatible client) two payment rails — gasless USDC on Base for crypto-native checkouts, and JIT single-use virtual cards for the 99% of the web that only takes cards — while the model never sees a real card number.

npx z-zero-mcp-server

What makes it different:

• 🔐 Zero-trust by design — the AI never sees PAN, CVV, or expiry. Card data exists only in RAM, injected via Playwright at the last step, then wiped.
• ⛽ Gasless USDC on Base — auto-detects crypto checkout (EIP-681) and settles as a gasless USDC transfer sponsored by Coinbase Paymaster. The agent holds only USDC — no ETH, no gas UX.
• 💳 JIT single-use virtual cards — amount-locked, 1-hour TTL, burned after a single use. Fiat fallback for the rest of the web.
• 🧠 Smart Routing + checkout intelligence — get_merchant_hints serves platform-specific checkout playbooks (Shopify, Etsy, WooCommerce…).
• ✍️ Linked purpose + outcome — the server signs the criteria the agent records at issuance. Before checkout, execute_payment hands those criteria back and requires a second call with go or pause; a confirmed purchase seals the answer into the signed receipt. The record is inspectable without pretending the platform judged whether the agent told the truth.
• 🔄 Structured failure labels — failed checkouts are labeled with a fixed 14-class failure_class (automatically, not only when an agent remembers to report) and stored as evidence for the merchant knowledge base. Facts are promoted into shared hints only after a later outcome or review verifies them.

Live on Base Mainnet

• ✅ Proof — real gasless USDC transfer on Base mainnet: 0xdfd1f2f8…5d7a
• Onboarding is just "deposit USDC" — no seed phrases in the agent, no native gas token, no exchange account.

How It Works

 User            AI Agent              MCP Tools              Z-ZERO API
  │                  │                      │                      │
  │ "Buy me this     │                      │                      │
  │  Shopify item"   │                      │                      │
  ├─────────────────▶│                      │                      │
  │                  │ read mcp://resources/sop (MANDATORY)        │
  │                  ├─────────────────────▶│                      │
  │                  │◀── platform rules ───┤                      │
  │                  │    + payment SOP     │                      │
  │                  │                      │                      │
  │                  │ get_merchant_hints("_platform_shopify")     │
  │                  ├─────────────────────▶│  GET /checkout-hints │
  │                  │                      ├─────────────────────▶│
  │                  │◀── pre_steps+notes ──┤◀──── hints data ─────┤
  │                  │                      │                      │
  │                  │ (fills shipping form, reaches payment page) │
  │                  │                      │                      │
  │                  │ request_payment_token(amount, cart, criteria)│
  │                  ├─────────────────────▶│                      │
  │                  │◀── temp_auth token ──┤   (1-hour TTL)       │
  │                  │                      │                      │
  │                  │ execute_payment(token, checkout_url)        │
  │                  ├─────────────────────▶│                      │
  │                  │◀── purpose_check ────┤  (nothing charged)   │
  │                  │  compare locked criteria with final page    │
  │                  │                      │                      │
  │                  │ execute_payment(..., recheck: go | pause)   │
  │                  ├─────────────────────▶│                      │
  │                  │      pause → no card is filled              │
  │                  │      go → Playwright fills + submits,       │
  │                  │      then burns token if confirmed 🔥       │
  │                  │◀──── ✅ success ─────┤                      │
  │ "Done! Your item │                      │                      │
  │  is ordered."    │                      │                      │
  │◀─────────────────┤                      │                      │

The AI agent never touches card data — it only handles single-use tokens. Real card details are injected by Playwright at the last step and wiped from RAM.

Crypto checkout branch: when auto_pay_checkout detects a crypto-native checkout (EIP-681), it skips the card flow entirely and settles as a gasless USDC transfer on Base — see above.

Why Z-ZERO

Z-ZERO is not a checkout bot — it's payment infrastructure for the agentic-commerce era (agentic transactions are projected to reach $1.5T by 2030 — Juniper Research).

Today, the web is built for humans: agents must fill forms and click buttons, and every purchase still needs a human's card. Z-ZERO solves that now — JIT single-use virtual cards + gasless USDC on Base, with card data isolated from the model. Tomorrow, agent payments become a standardized protocol — and what we build along the way is the long-term value:

• Shared checkout intelligence — every transaction (and every failure) makes the network smarter.
• An open standard for agent payments — any agent platform plugs in via MCP; any rail (cards, USDC, x402) can be added.
• KYA — Know Your Agent — verifiable agent reputation. The question isn't "can this agent pay?" but "should you trust it to?"

📖 Full vision & architecture: The Z-Zero Whitebook

Quick Install (Recommended)

npx z-zero-mcp-server

Add to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json):

{
  "mcpServers": {
    "z-zero": {
      "command": "npx",
      "args": ["-y", "z-zero-mcp-server@latest"],
      "env": {
        "Z_ZERO_API_KEY": "zk_live_your_passport_key_here"
      }
    }
  }
}

Get your Passport Key at: z-zero.xyz/dashboard/agents

Security: rotate-on-connect (v1.5.0+)

The key you copy from the dashboard (or paste into a chat) is only a one-time bootstrap ticket. The moment your agent connects with it, the MCP server silently swaps it for a fresh key:

• The fresh key travels server → MCP process → disk and is stored in ~/.z-zero/credentials (mode 0600). It never appears in any LLM conversation, tool result, or config file.
• The pasted key is dead within seconds — a copy living in a chat transcript, clipboard, or screenshot can no longer be used by anyone.
• On startup the MCP loads the key from ~/.z-zero/credentials first; the Z_ZERO_API_KEY env var is only a bootstrap fallback.

One key = one machine. All agents on the same machine (Claude Desktop, Claude Code, Cursor, …) share the same MCP install and the same credentials file — install once, every agent can pay. Connecting a different machine with a copied key rotates it, which instantly disconnects the original machine. That is deliberate: it blocks key sharing and doubles as an intrusion alarm — if your agent suddenly fails auth, someone else used your key; go to the dashboard and revoke.

Older self-hosted backends without the rotate endpoint keep working — the pasted key simply stays active as before.

Requirements

• Node.js v18+ — nodejs.org
• Passport Key — starts with zk_live_, get it from the dashboard above

Available MCP Tools

Group 1 — Wallet Config (Passive)

Group 2 — Manual Card Payment (Active)

Group 3 — Smart Autopilot