Verifiable receipt aa1a211c - day_pass_activate result | Zambo

Verifiable receipt for a day_pass_activate call on Zambo: { "receipt_id": "d55a4f61-9ef1-4ab7-8d45-e6f647df9332", "type": "refusal", "timestamp": "2026-10-09T22

Observed result

{
  "receipt_id": "d55a4f61-9ef1-4ab7-8d45-e6f647df9332",
  "type": "refusal",
  "timestamp": "2026-10-09T22:07:03.095Z",
  "resource": {
    "url": "https://zambo.dev/api/x402/day-pass",
    "description": "Zambo Day Pass: $0.99 in Base USDC for 24-hour access to the Zambo MCP connection. Not per call - one payment covers 24 hours. Every call returns a verifiable receipt.",
    "mimeType": "application/json"
  },
  "policy_reason": "invalid_base64",
  "detail": "Correct the payment envelope: invalid_base64.",
  "retryable": true,
  "quoted_max_amount": "990000",
  "amount_units": "USDC_atomic_6dp",
  "settlement_window": {
    "opens_at": "2026-10-09T22:07:03.095Z",
    "closes_at": "2026-10-09T22:22:03.095Z"
  },
  "verifier_url": "https://zambo.dev/api/x402/refusal-receipt/d55a4f61-9ef1-4ab7-8d45-e6f647df9332/audit",
  "attempt_hash": "sha256:960aeef51ddcd63a64564edab06f07d933a8d73ca770a4fd553d9f1ac4a96979",
  "challenge_ref": {
    "resource": "https://zambo.dev/api/x402/day-pass",
    "network": "eip155:8453",
    "asset": "0x8335…2913",
    "pay_to": "0xb753…b9AC",
    "amount": "990000",
    "max_timeout_seconds": 900,
    "issued_at": "2026-10-09T22:07:03.095Z"
  },
  "message": "Correct the payment envelope: invalid_base64.",
  "docs": "https://zambo.dev/for-agents",
  "diagnostic": {
    "code": "invalid_base64",
    "field": null,
    "issue": "The payment could not be validated.",
    "fix": "Request a fresh challenge and use an official x402 client."
  },
  "official_client": {
    "repository": "https://github.com/coinbase/x402",
    "packages": [
      "@x402/fetch",
      "@x402/evm"
    ]
  },
  "challenge": {
    "x402Version": 2,
    "error": "Payment required",
    "no_wallet": "No wallet found. Pay $0.99 with PayPal at https://zambo.dev/day-pass. ",
    "human_url": "https://zambo.dev/day-pass",
    "agent_payment": {
      "tool": "day_pass_activate",
      "step_1": "GET https://zambo.dev/api/x402/day-pass without payment to receive the live challenge",
      "amount_usdc": "0.99",
      "amount_atomic": "990000",
      "asset": "USDC",
      "network": "eip155:8453",
      "network_name": "Base",
      "step_2": "Only after explicit human approval, POST https://zambo.dev/api/x402/day-pass with X-Payment: <base64 JSON x402 envelope>",
      "approval_required": "Obtain explicit human approval before signing or submitting a payment.",
      "activation": "24-hour access; never activates without a verified transfer",
      "endpoint": "https://zambo.dev/api/mcp"
    },
    "resource": {
      "url": "https://zambo.dev/api/x402/day-pass",
      "description": "Zambo Day Pass: $0.99 in Base USDC for 24-hour access to the Zambo MCP connection. Not per call - one payment covers 24 hours. Every call returns a verifiable receipt.",
      "mimeType": "application/json"
    },
    "payment_proof": {
      "header": "X-Payment",
      "destination": "https://zambo.dev/api/x402/day-pass",
      "encoding": "base64(JSON {x402Version,scheme,network,payload:{signature,authorization}})",
      "required": true
    },
    "unlocks": "24-hour access to the Zambo MCP connection, subject to product/provider allowances listed at https://zambo.dev/pricing",
    "on_success_returns": [
      "receipt_url",
      "run_id",
      "uuid",
      "access_key",
      "expires_at",
      "x402_spend_receipt",
      "settlement_tx_hash"
    ],
    "accepts": [
      {
        "scheme": "exact",
        "network": "eip155:8453",
        "asset": "0x8335…2913",
        "amount": "990000",
        "payTo": "0xb753…b9AC",
        "maxTimeoutSeconds": 900,
        "extra": {
          "name": "USD Coin",
          "version": "2",
          "domain": {
            "name": "USD Coin",
            "version": "2",
            "chainId": 8453,
            "verifyingContract": "0x8335…2913"
          },
          "types": {
            "TransferWithAuthorization": [
              {
                "name": "from",
                "type": "address"
              },
              {
                "name": "to",
                "type": "address"
              },
              {
                "name": "value",
                "type": "uint256"
              },
              {
                "name": "validAfter",
                "type": "uint256"
              },
              {
                "name": "validBefore",
                "type": "uint256"
              },
              {
                "name": "nonce",
                "type": "bytes32"
              }
            ]
          },
          "primaryType": "TransferWithAuthorization",
          "message": {
            "from": "<payer_address>",
            "to": "0xb753…b9AC",
            "value": "990000",
            "validAfter": "<unix_seconds>",
            "validBefore": "<unix_seconds>",
            "nonce": "<bytes32_nonce>"
          }
        }
      }
    ]
  },
  "agent_flow": "Ask the human for explicit approval before signing. After approval, sign the typed EIP-3009 TransferWithAuthorization message from accepts[0].extra, base64-encode the x402 JSON envelope, and retry with x_payment plus human_approved=true."
}

Provenance for every timeline entry

Private agent reasoning, built-in client actions, and direct calls to unrelated MCP servers are not included unless an agent or gateway reports them.

What is this?

Zambo's receipt store reports a tool call and records its result. The SHA-256 commitment covers the exact canonical bytes. The provenance label is bound to v0.4 receipt bytes when that check passes, but no pinned signature or trusted issuer key is checked. An anchor can timestamp a fingerprint; it does not authenticate the issuer.

What is an execution receipt?

An execution receipt is a public record of a reported AI agent tool call. Its byte commitment and provenance claim can be checked independently; neither alone authenticates the issuer. Read the canonical definition of an AI agent execution receipt.

Keep the work moving

This receipt records a completed tool call. When the free allowance is not enough, choose the access path that fits the job.

UNLOCK 24H DAY PASS ($0.99) →

See all plans on the pricing page →

RUN YOUR OWN FREE CALL →

Or re-run this exact call, using the same tool and arguments.

Share this receipt

Share on X ·

Verification checks

Committed provenance claim

EXECUTED BY ZAMBO

The metadata claim is consistent with the verified receipt bytes; issuer is not authenticated.

Receipt ID
aa1a211c-d2e3-4841-8558-ead63a8b8ec1
SHA-256 output hash
sha256:e4832bd6bc6d0ed79c5d169ebb0ea22a287bac7c662f17fa8f7f67668d23bf34
Canonical bytes
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
Timestamp

Bound call context

Receipt schema
0.4
Tool name
day_pass_activate
Tool version
4.0.0
Permission scope
public
Caller type
anonymous
Caller ID
sha256:8c0b37967f520e65fd2651723658fce416dafd866e5df569e6716ffaddea79ac
Declared side effects
state_write
Side-effects schema
zambo-side-effects/1
Declaration hash
sha256:dfb4412aa429d3ac637a05668c435bcc90a251363fcdd49f7b85ae4ab55b5bc9

This records what the server-side tool contract declared at call time. It does not independently verify that a downstream side effect happened.

Bound upstream evidence

Status
captured
Evidence SHA-256
sha256:c4a5c7975981eb9e00180886ebcf19895bc15e6ff52cdad967f4ab68ca0d0a6e
Byte length
3831

Fetch exact evidence bytes

Neutral Nostr anchor

Event ID
c1e8db20275c9fdbae93ede0b1c46adf5fa8e831ea653882fac809fcc70e205c
Anchor status
partial
Public key
e13475107d30c918ec664adf2ab1141024a22fb35190f82c9e933704fa49af41

Relay hints: wss://relay.damus.io · wss://nos.lol · wss://relay.primal.net

Schema: zambo-receipt-anchor/1

Anchor envelope bytes:

{"anchored_at":"2026-10-09T22:07:03.130Z","evidence_byte_length":3831,"evidence_sha256":"sha256:c4a5c7975981eb9e00180886ebcf19895bc15e6ff52cdad967f4ab68ca0d0a6e","evidence_url":"https://zambo.dev/api/evidence/c4a5c7975981eb9e00180886ebcf19895bc15e6ff52cdad967f4ab68ca0d0a6e","output_sha256":"sha256:e4832bd6bc6d0ed79c5d169ebb0ea22a287bac7c662f17fa8f7f67668d23bf34","receipt_uuid":"aa1a211c-d2e3-4841-8558-ead63a8b8ec1","schema_version":"zambo-receipt-anchor/1"}

Anchor status "partial": Published to some configured relay targets; publication was not confirmed by every configured relay.

Check this hash yourself

Recompute the SHA-256 commitment in your browser. Open the API v2 JSON response to inspect the machine-readable checks. Signature and chain remain NOT CHECKED unless a real signature verifier or chain proof is supplied. There is no combined “verified” verdict. See the Nostr anchor event on a public viewer. The fingerprint is timestamped outside Zambo too.

Embed this receipt

Markdown

[![Verifiable Zambo receipt](https://zambo.dev/api/receipt/aa1a211c-d2e3-4841-8558-ead63a8b8ec1/badge.svg)](https://zambo.dev/run/aa1a211c-d2e3-4841-8558-ead63a8b8ec1)

HTML

<a href="https://zambo.dev/run/aa1a211c-d2e3-4841-8558-ead63a8b8ec1"><img src="https://zambo.dev/api/receipt/aa1a211c-d2e3-4841-8558-ead63a8b8ec1/badge.svg" alt="Verifiable Zambo receipt"></a>

Open badge SVG

Recent receipts

41,274 verifiable receipts minted

RUN YOUR OWN FREE CALL →

Run your own calls. Free, 20 free calls per metered tool each day, no account.

Open the interactive receipt view