Opportunities Delta

{
  "changed": true,
  "confidence": 1,
  "event_count": 1,
  "events": [
    {
      "current": [
        "https://sam.gov/example/attachment-v2"
      ],
      "event": "attachments_changed",
      "field": "resource_links",
      "materiality": 0.85,
      "previous": [
        "https://sam.gov/example/attachment-v1"
      ],
      "reason": "Attachment/resource changes may alter requirements."
    }
  ],
  "material_changed": true,
  "material_event_count": 1,
  "notice_id": "example-notice-id",
  "product": {
    "event_digest": "example",
    "price": {
      "amount": "0.01",
      "currency": "USD"
    },
    "product_event_id": "product_example",
    "product_id": "federal_opportunity.delta",
    "product_version": "1"
  },
  "provenance": {
    "materiality_threshold": 0.65,
    "source": "SAM.gov"
  },
  "source": "SAM.gov"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://myc-staging.crescadia.com/v1/paid/opportunities/:notice_id/delta'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://myc-staging.crescadia.com/v1/paid/opportunities/:notice_id/delta' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.01 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.01" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.01 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fmyc-staging.crescadia.com%2Fv1%2Fpaid%2Fopportunities%2F%3Anotice_id%2Fdelta
const res = await pay("https://myc-staging.crescadia.com/v1/paid/opportunities/:notice_id/delta");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.01 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.01"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://myc-staging.crescadia.com/v1/paid/opportunities/:notice_id/delta")
    print(res.status_code, res.text)