One cryptographic boundary between an AI agent and payment.

QUICKSTART

Verify signed authority before payment execution.

const result = await fetch(
  "https://mandateshield.com/api/v2/verify",
  {
    method: "POST",
    headers: {
      "content-type": "application/json",
      "authorization": "Bearer ms_live_..."
    },
    body: JSON.stringify({
      envelope: purchaseEnvelope,
      evidence: signedAuthority
    })
  }
).then(response => response.json())

if (
  result.assurance.status !== "VERIFIED" ||
  result.decision !== "ALLOW"
) {
  throw new Error("Payment blocked by MandateShield")
}

await charge()
store(result.signed_receipt.compact)

STRICT V2 PROFILE

Verify the proof, not a protocol label.

Send compact JWS, AP2 SD-JWT or a TAP-style HTTP message signature under `evidence`. The signature must be current and bound to the evaluated purchase through AP2 payment claims, TAP authority/path components or the canonical `mandateshield_input_digest`. Missing or mismatched evidence fails closed. The API verifies against the supplied JWK; production callers must pin that key or resolve it through their AP2/TAP issuer trust registry.

{
  "envelope": { "...": "the final purchase facts" },
  "evidence": {
    "format": "jws",
    "compact": "eyJhbGciOiJFUzI1NiIs...",
    "public_key": { "kty": "EC", "crv": "P-256", "...": "..." },
    "expected_audience": "merchant_checkout",
    "expected_nonce": "fresh_challenge"
  }
}

REQUEST

A protocol-neutral purchase envelope.

MandateShield accepts normalized fields from AP2, TAP, UCP, x402, ACP or a custom signed envelope. Never send card numbers, bank credentials, private keys or personal shopping data.

{
  "protocol": "AP2",
  "mandate_id": "mnd_2048",
  "agent_id": "agent_travel_07",
  "merchant_id": "merchant_rail",
  "amount": { "value": 124.90, "currency": "USD" },
  "limits": {
    "max_amount": 150,
    "currencies": ["USD"],
    "merchants": ["merchant_rail"]
  },
  "created_at": "2026-07-24T18:50:00Z",
  "expires_at": "2026-07-24T19:00:00Z",
  "idempotency_key": "order_9f22a1",
  "intent_hash": "sha256:...",
  "user_consent": true,
  "credential_binding": "tap:merchant_rail:agent_travel_07"
}

RESPONSE

ALLOW, REVIEW or BLOCK.

Every response includes machine-readable findings, a CLEAR to CRITICAL risk level, budget headroom, the value blocked at the boundary, a recommended next action and a SHA-256 receipt hash. Strict v2 responses additionally include cryptographic assurance metadata and an ES256-signed portable receipt. Verify it through `POST /api/v2/receipts/verify` or the public `/.well-known/jwks.json`. `ALLOW` means the supplied facts passed the configured controls; it is not a guarantee that a transaction is legitimate.

AUTHENTICATION

Bearer keys with test and live modes.

Create and revoke keys in the dashboard. A key is shown once, stored only as a SHA-256 hash and can be revoked without changing other integrations.

HIGH-VOLUME BATCH

Evaluate up to 25 purchases in one request.

Send the same envelopes to `POST /api/v1/batch` as a JSON array or under a `purchases` property. Every item keeps its own decision, receipt, replay protection and usage record; the response adds an ALLOW, REVIEW, BLOCK and error summary.

REPLAY PROTECTION

One decision per idempotency key.

Live and test keys persist each decision. Reusing the same idempotency key with a key returns HTTP 409 and `REPLAY_DETECTED`. Generate a new key only for a genuinely new payment attempt.

HTTP STATUS

Errors fail closed.