@railslab/sdk

Agent spend control SDK. Pay for API resources through Rails Lab.

Install

npm install @railslab/sdk

Usage

import { Leet } from '@railslab/sdk'

const leet = new Leet({ apiKey: 'leet_abc123...' })

// Pay for a resource — protocol is auto-detected
const { content } = await leet.pay('https://pro-api.coingecko.com/api/v3/x402/simple/price?vs_currencies=usd&ids=bitcoin')
console.log(content) // { bitcoin: { usd: 70925 } }

Options

const result = await leet.pay('https://api.example.com/resource', {
  amountCents: 1,          // Budget debit amount (default: 1 cent)
  protocol: 'x402',        // Skip auto-detection
  method: 'POST',          // HTTP method for the destination
  body: '{"key": "val"}',  // JSON body for POST destinations
  idempotencyKey: 'abc',   // For safe retries
  metadata: { env: 'prod' },
})

Error handling

import { Leet, LeetError } from '@railslab/sdk'

try {
  await leet.pay('https://api.example.com/resource')
} catch (err) {
  if (err instanceof LeetError) {
    console.log(err.code)    // "POLICY_DENIED", "BUDGET_EXCEEDED", etc.
    console.log(err.message) // Human-readable message
    console.log(err.status)  // HTTP status code
  }
}

Supported protocols

| Protocol | Description | |----------|-------------| | x402 | USDC payments on Base via Coinbase x402 | | mpp-crypto | Tempo stablecoin payments via MPP | | mpp-spt | Stripe card payments via MPP (coming soon) |

Protocol is auto-detected from the destination's 402 response. You can also specify it explicitly via the protocol option.