Your yield pays your AI agent's API bills
Deposit USDC once. Earn yield. Your agent pays for x402 APIs from that yield — principal isn't spent on API calls.
x402 lets agents pay for APIs over HTTP, per call. But the money behind those payments still comes from a human refilling a wallet — and the humans doing their own research keep losing.
An agent's wallet runs out. A human tops it up. It runs out again. Autonomy ends the moment the balance hits zero, and somebody has to be there to refill it — every time.
Impulsive, manual trading loses to data-driven decisions — the kind an agent armed with paid market data can make around the clock. Most people never get that far.
Yield keeps paying for paid APIs. Principal isn't spent on API calls.
An agent deposits USDC into the Subly vault once. The vault earns DeFi yield on Kamino, and every x402 API call settles from the yield that accrues. The relayer refuses any payment beyond spendable yield, so the deposited principal is never touched by a payment — and stays withdrawable at any time.
The agent transfers USDC into the Subly vault once. Principal stays in your custody and can be withdrawn at any time — a plain withdraw is the exit path.
Deposited capital earns yield in DeFi through the Subly vault on Kamino, with a 5-10% APY target. Yield, not principal, funds your agent's calls.
Payments settle from spendable yield only. The relayer refuses anything the accrued yield cannot cover, so API calls cannot eat into the deposit.
The agent makes one USDC transfer into the Subly vault on Kamino. No SOL needed — network fees are sponsored, and the principal stays withdrawable.
The vault lends deposits in DeFi with a 5-10% APY target. Yield accrues continuously and becomes the agent's spendable payment budget.
The agent calls x402-enabled APIs — Birdeye at $0.003, CoinGecko or Nansen at $0.01 — and each call settles from yield with an on-chain receipt.
1,000 USDC at 10% APY covers 27 API calls a day at $0.01 each.
Before fees. Subly charges 10% of yield and 1% of each payment — either way, the payment path never draws on principal.
One npm package — an MCP server, an agent skill, and a CLI.
@subly_fi/pay ships the whole lifecycle: owner onboarding, deposits, yield budget, paid fetches, withdrawals. It runs anywhere MCP runs — Claude Code, Claude Desktop, Cursor — and as an OpenClaw skill. No API key, no clone, nothing to deploy.
Registers the Subly MCP server for Claude Code. The same npx command works in Cursor and any other MCP client.
claude mcp add subly -- npx -y @subly_fi/pay mcpSettings → Developer → Edit Config, paste, restart. GUI apps don't read your shell env, so the keypair path goes in the env block — as an absolute path.
{
"mcpServers": {
"subly": {
"command": "npx",
"args": ["-y", "@subly_fi/pay", "mcp"],
"env": {
"SUBLY_DEMO_AGENT_KEYPAIR_PATH": "/Users/you/.subly/agent.json"
}
}
}
}The subly-pay skill from ClawHub teaches an OpenClaw agent when to pay, how to read receipts, and when to stop. It shells out to the same npx package.
openclaw skills install subly-payPays for a single x402 URL from yield and prints a JSON receipt — amount, payee, and a Solscan link. This is also what the skill runs under the hood.
npx -y @subly_fi/pay fetch "https://seller.example.com/api/premium"Owner onboarding. One Face ID approves the spending mandate and the first deposit.
Confirms the human owner finished setup before anything moves.
Moves USDC into the vault on Kamino. Minimum is just over 1 USDC.
Shows how much spendable yield the agent has right now.
Fetches any x402 URL. The call settles from yield and returns a receipt.
The exit path. Principal returns to the agent wallet.
A human owner stays in charge: setup, spending limits, and anything above the approval threshold are confirmed with Face ID or a wallet signature. After that, the flow is hands-free.
Bring your own Solana key — or a Circle / Privy custody wallet. Subly never holds it.
solana-keygen new -o ~/.subly/agent.jsonSend USDC on Solana mainnet to the printed address. No SOL needed — network fees are sponsored.
The agent sends a one-time setup link. The owner reviews the spending limits and approves the mandate plus the first deposit with one Face ID.
Point the agent at any x402 paywall. It pays from vault yield and returns the response plus a Solscan receipt.
A client-side cap on every call, and a server-side guard that refuses to realize anything beyond spendable yield. The deposited principal is never touched by a payment.
Your key signs locally and never reaches Subly. Circle and Privy custody wallets work too.
Every call is capped client-side — 0.01 USDC by default. Raising it is a deliberate act.
Deposits, and payments above your threshold, pause for a Face ID approval link first.
The relayer refuses payments beyond spendable yield. No API call can draw on principal.
Agents are becoming one of the fastest-growing consumers of paid APIs.
Subly starts with API Payments via AI Agents: the per-call API payments an agent makes through x402-style HTTP 402. From there, it can grow into the broader agent economy.
We're onboarding the first 100 users who run AI agents for financial research.