MCP Tool · x402 · early usage

Call after your agent completes an action it may later have to prove: seal the hashes o…

by gblin.digital · discovered, not yet claimed by its owner · updated 2026-10-11

30d calls4

30d payers4

MethodPOST

Outputjson

Mirrored from Coinbase's public x402 Bazaar. The description is the provider's own text and has not been reviewed here; the payment requirements are copied as published.

What it does

Call after your agent completes an action it may later have to prove: seal the hashes of its input and output (only your action label and meta are published) into GBLIN's signed append-only transparency log and get a portable receipt: Ed25519 signature, RFC 6962 inclusion proof, C2SP signed checkpoint; root anchored daily on Base (EAS). Proves existence and time, not correctness. Free reads and demo: gblin-mcp.gblin-mcp-worker.workers.dev/log

Tags: bazaar

Call contract

Method: POST
Input: json
Output: json
Last paid call: 2026-10-11

Input example from Bazaar metadata

{
  "action": "summarise-contract",
  "input_hash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
}

Output example

{
  "checkpoint": "<C2SP signed note>",
  "format": "gblin-receipt/v1",
  "inclusion_proof": [
    "<base64 node>",
    "<base64 node>"
  ],
  "index": 42,
  "leaf": "<base64 sha256(0x00 || canonical)>",
  "payload": {
    "action": "summarise-contract",
    "index": 42,
    "input_hash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
    "log": "gblin.digital/receipts-log",
    "output_hash": null,
    "ts": "2026-08-30T09:00:00.000Z",
    "v": 1
  },
  "root": "<base64 Merkle root>",
  "signature": "<base64 Ed25519 over the canonical record>",
  "tree_size": 43,
  "verifier_key": "gblin.digital/receipts-log+00c6e18c+...",
  "verify": "offline: see verify-receipt.mjs in github.com/gblinproject/gblin-treasury-risk-regime (zero deps)"
}

Use with an agent

Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
Inspect. Fetch /resources/32603.json for the price and payment options.
Pay. Call GET https://gblin.digital/api/x402/seal. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.0045 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base
Demand: 4 calls · 4 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.0045	0x0ebA5d314F4f5Dcb7A094953Fa9311a45172dd1B	300s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x0ebA5d314F4f5Dcb7A094953Fa9311a45172dd1B",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "4500",
    "amountUsd": 0.0045,
    "maxTimeoutSeconds": 300
  }
]

Schemas

Output schema (JSON Schema)

{
  "properties": {
    "example": {
      "type": "object"
    },
    "type": {
      "type": "string"
    }
  },
  "required": [
    "type"
  ],
  "type": "object"
}

Example shape — generated from the schema, not a captured live response

{
  "example": {},
  "type": "string"
}

Examples

curl

curl "https://gblin.digital/api/x402/seal"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

JavaScript

const res = await fetch("https://gblin.digital/api/x402/seal");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

Python

import httpx
res = httpx.get("https://gblin.digital/api/x402/seal")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider: gblin.digital
Endpoint: https://gblin.digital/api/x402/seal
Machine-readable: /resources/32603.json