Delta

{
  "composite": null,
  "from": {
    "run_at": "2026-07-12T14:00:05.754191+00:00",
    "snapshot_id": "2026-07-12"
  },
  "kind": "delta",
  "n_moved": 76,
  "n_sources": 129,
  "schema_version": "0.2",
  "sources": [
    {
      "delta_abs": 1086,
      "delta_pct": 61.0455,
      "domain": "agents",
      "from": {
        "date": "2026-07-12",
        "value": 1779
      },
      "id": "agents.x402_services_count",
      "metric": "x402 pay-per-request services (agentic.market)",
      "new_observation": true,
      "to": {
        "date": "2026-09-16",
        "value": 2865
      },
      "unit": "count"
    },
    {
      "delta_abs": 0,
      "delta_pct": 0,
      "domain": "autonomy",
      "from": {
        "date": "2025-04-16",
        "value": 112.230447
      },
      "id": "autonomy.metr_time_horizon_50",
      "metric": "METR frontier task-completion horizon @50% (minutes)",
      "new_observation": false,
      "to": {
        "date": "2025-04-16",
        "value": 112.230447
      },
      "unit": "minutes"
    }
  ],
  "to": {
    "run_at": "2026-09-16T12:25:28.530204+00:00",
    "snapshot_id": "2026-09-16"
  }
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://x402-accelerometer-feed.fly.dev/delta/:from/:to'

# 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://x402-accelerometer-feed.fly.dev/delta/:from/:to' \
  | 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%2Fx402-accelerometer-feed.fly.dev%2Fdelta%2F%3Afrom%2F%3Ato
const res = await pay("https://x402-accelerometer-feed.fly.dev/delta/:from/:to");
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://x402-accelerometer-feed.fly.dev/delta/:from/:to")
    print(res.status_code, res.text)