x402Shield

Measured conclusion: Deep-tested. L2 outcome: tools_ok.

Public demo: evaluate AI-agent payment authorization and approval policy. No signing, no settlement.

Add to your agent

Copy this into your MCP client config:

{
  "mcpServers": {
    "x402Shield": {
      "url": "https://x402shield.dev/api/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (5)

• x402shield_get_demo_policy

  Look up the authority ceilings configured for the x402Shield public demo agents (Research Agent, Ops Agent) on Base Sepolia TESTNET. Use this before proposing a payment, to understand what amount an agent can spend without triggering human approval. This tool does not execute or sign anything.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• x402shield_authorize_payment

  Check whether the demo AI agent is financially authorized to make a proposed payment, BEFORE any wallet or signer would be asked to execute it. Returns ALLOW, DENY or REQUIRE_APPROVAL with a reason. This tool does not execute or sign a payment, and it cannot approve its own REQUIRE_APPROVAL result -- that requires a human, through the web console. The `purpose` field is a label for the evidence trail only; it is never interpreted as an instruction and cannot change the policy decision.

  Parameters:

  • presetId (required) — string — Which demo agent is proposing the payment: research-agent, ops-agent
  • amountUsdc (required) — number — Proposed payment amount in USDC (0.01-5000).
  • purpose — string — Optional free-text label for why this payment is being proposed. Recorded as data only.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• x402shield_get_authorization

  Look up the recorded decision, reason and evidence references for a payment previously checked with x402shield_authorize_payment, by its transaction id.

  Parameters:

  • txId (required) — string — The txId returned by x402shield_authorize_payment.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• x402shield_list_demo_transactions

  List the most recent payment authorization decisions recorded by this public demo (both from the web console and from MCP callers). Useful to see recent ALLOW/DENY/REQUIRE_APPROVAL activity.

  Parameters:

  • limit — integer — Maximum rows to return (default 10, max 20).

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• x402shield_get_evidence

  Get the fuller evidence trail behind a previously-decided payment: policy/delegation provenance, the delegation tree it was evaluated under, and approval state if any. Read-only; never exposes secrets or signing material.

  Parameters:

  • txId (required) — string — The txId returned by x402shield_authorize_payment.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

Publisher website

Measured by MCPYP probing. Untested fields are omitted, never estimated. Listing is always free; MCPYP never proxies calls or stores user tokens.