Bin Pack

{
  "algorithm_version": "best-fit-decreasing-v1",
  "certificate": {
    "algorithm": "best-fit-decreasing-v1",
    "capacity": 10,
    "capacity_feasible": true,
    "item_conservation": true,
    "item_count": 5,
    "total_size": 30,
    "volume_lower_bound": 3
  },
  "objective": "minimum_bin_count",
  "objective_value": 4,
  "operation": "bin-pack",
  "optimal": false,
  "optimality_gap_upper_bound": 1,
  "solution": {
    "bin_count": 4,
    "bins": [
      {
        "index": 0,
        "items": [
          {
            "id": "a",
            "original_index": 0,
            "size": 8
          }
        ],
        "load": 8,
        "remaining": 2
      },
      {
        "index": 1,
        "items": [
          {
            "id": "b",
            "original_index": 1,
            "size": 7
          }
        ],
        "load": 7,
        "remaining": 3
      },
      {
        "index": 2,
        "items": [
          {
            "id": "c",
            "original_index": 2,
            "size": 6
          },
          {
            "id": "e",
            "original_index": 4,
            "size": 4
          }
        ],
        "load": 10,
        "remaining": 0
      },
      {
        "index": 3,
        "items": [
          {
            "id": "d",
            "original_index": 3,
            "size": 5
          }
        ],
        "load": 5,
        "remaining": 5
      }
    ]
  },
  "warnings": [
    "Best-fit decreasing is a heuristic; a nonzero reported bound is only an upper bound on the unknown optimality gap."
  ],
  "work_units": 10
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://decision-solver.use.x402atlas.com/bin-pack' \
  -H 'content-type: application/json' \
  --data-raw '{"capacity":10,"items":[{"id":"a","size":8},{"id":"b","size":7},{"id":"c","size":6},{"id":"d","size":5},{"id":"e","size":4}]}'

# 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 - -X POST 'https://decision-solver.use.x402atlas.com/bin-pack' \
  -H 'content-type: application/json' \
  --data-raw '{"capacity":10,"items":[{"id":"a","size":8},{"id":"b","size":7},{"id":"c","size":6},{"id":"d","size":5},{"id":"e","size":4}]}' \
  | 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 $0.005 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.005" });
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 $0.005 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fdecision-solver.use.x402atlas.com%2Fbin-pack&method=POST
const res = await pay("https://decision-solver.use.x402atlas.com/bin-pack", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "capacity": 10,
    "items": [
      {
        "id": "a",
        "size": 8
      },
      {
        "id": "b",
        "size": 7
      },
      {
        "id": "c",
        "size": 6
      },
      {
        "id": "d",
        "size": 5
      },
      {
        "id": "e",
        "size": 4
      }
    ]
  }),
});
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 $0.005 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.005"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://decision-solver.use.x402atlas.com/bin-pack",
        json={
            "capacity": 10,
            "items": [
                {
                    "id": "a",
                    "size": 8,
                },
                {
                    "id": "b",
                    "size": 7,
                },
                {
                    "id": "c",
                    "size": 6,
                },
                {
                    "id": "d",
                    "size": 5,
                },
                {
                    "id": "e",
                    "size": 4,
                },
            ],
        },
    )
    print(res.status_code, res.text)