# Give an Agent a Budget Every agent spends through a policy you set — a daily limit and a list of who it's allowed to pay. Set it once, and the agent can't go past it. ## What a budget looks like For each token an agent can spend, you set a daily cap and an allowlist of recipients: ```json { "max_daily_spend": 500000000, "allowed_recipients": "0xApiProvider,0xOtherVendor" } ``` * **`max_daily_spend`** — the most the agent can spend per day, in the token's smallest units. USDC has 6 decimals, so `500000000` is 500 USDC. Use `0` for no limit. * **`allowed_recipients`** — who the agent can pay: a comma-separated list of addresses, or `*` for anyone. You can go further — a per-transaction cap for a specific vendor, or requiring every recipient to be on a verified list. ## How it's enforced When an agent tries to pay, its policy is checked off-chain by Newton Protocol and confirmed before any funds move. A payment over the cap, or to someone not on the list, is declined — the agent never touches money it isn't allowed to spend. You stay in control without trusting the agent's key. ## Set it with the SDK ```typescript import { buildPolicyParams } from "@newton-xyz/isaac"; import { toHex } from "viem"; const params = buildPolicyParams({ "0xAgentAddress": { "0x8cfff8Bc9aA3d41fb9608496705CbfC83EBFc67c": { max_daily_spend: 500_000_000, // 500 USDC/day allowed_recipients: "*", }, }, }); // Register it for the agent (a hex-encoded blob is what the platform expects): const policyParams = toHex(JSON.stringify(params)); ``` ## Next * **[Pay for an API](/guides/pay-for-an-api)** — put the budget to work.