Guide

Use Aut from Ostra

Ostra gives an AI agent its own vault of USDG on Robinhood Chain. Its MCP server, @ostraagent/mcp, can find Aut's APIs and pay for each call from that vault. The agent asks autonomo_catalog what's available, then calls one with pay.

Works with	Every API listed on Aut, paid in USDG on Robinhood Chain
The agent needs	Ostra's MCP server and a vault with a little USDG. No BNB: Ostra's relayer takes gas in USDG
Tools	Ostra's `autonomo_catalog` and `pay`, from version 0.1.21

Set up

01Add Ostra's MCP server

It needs Node.js 22 or later and no configuration. In Claude Code:

bash

claude mcp add ostra -- npx -y @ostraagent/mcp

In Claude Desktop, Cursor and other MCP clients:

json

{
  "mcpServers": {
    "ostra": {
      "command": "npx",
      "args": ["-y", "@ostraagent/mcp"]
    }
  }
}

02Open the vault and fund it

Ask the agent to call open_vault. It returns the vault's address: send USDG on Robinhood Chain to it, and balance shows it. A dollar or two is plenty to start, since most APIs cost 0.01 USDG.

The vault's keys stay on your machine, in ~/.ostra. Back up its seed as Ostra's docs explain, in a terminal rather than through the agent.

03Set up the payment wallet

Ask the agent to call payment_wallet_setup. Aut's APIs are paid with a signed USDG transfer, so Ostra pays them from a separate wallet derived from the same seed. It never holds more than 5 USDG and is topped up from the vault, 1 USDG at a time or what a price needs, so the vault itself isn't exposed.

Running a second server with its own agent key (vault version 5)? Then the owner allows that agent's payment wallet first, by calling payment_wallet_setup with its agentWallet on the owner's server. See Ostra's docs.

Find an API and pay for it

01See what's available

autonomo_catalog reads Aut's public list of APIs, /api/v1/gateways. For each one, it gives what it does, an example URL to call, its price in USDG, whether it's Verified, and its track record over 30 days: paid calls, success rate and speed. It's free.

02Call one with pay

Give pay the API's URL, with its example's <…> part filled in, and the most it may cost. For example, to find agents on Ostrapad who write a protocol risk report with the Ostrapad Offer Finder:

pay

{
  "url": "https://autai.xyz/x/ostrapad-offer-finder/offers?q=protocol%20risk%20report",
  "maxPrice": "0.01"
}

Or just ask the agent, for example "use Aut's Offer Finder to find an Ostrapad agent for a protocol risk report", and it makes these calls itself.

03Get the answer

Ostra reads the API's price, signs one USDG payment for exactly that amount to that API, and sends the request with it. Aut settles the payment on-chain and pays the gas. payment_wallet_status lists the payments made.

The tools

open_vault, balance	The agent's Ostra vault: its address, to fund with USDG, and what it holds
payment_wallet_setup	Sets up the wallet that pays Aut's APIs, and tops it up from the vault
autonomo_catalog	Lists Aut's APIs: what each does, how to call it, its price, Verified and its track record
pay	Calls an API and pays its price in USDG, refused before signing above maxPrice
payment_wallet_status	The payment wallet's balance and its last payments

Good to know

If the API fails, the agent isn't charged: the payment only settles when the API answers properly.
A price above maxPrice is refused before anything is signed. Ostra's vault policy and limits apply on top.
Ostra pays in USDG. Paying in $AUTONOMO isn't supported from Ostra; use the Aut MCP server or the SDK for that.
Payments aren't private: the payment wallet, its top-ups from the vault and each payment are public on Robinhood Chain. To pay without linking back to a wallet, see Pay privately with Gloam.
Prefer the APIs marked Verified with a good track record. Aut lists outside creators' APIs too, and doesn't vouch for each one.
The vault, the payment wallet and the MCP server are Ostra's. For how they work, see Ostra's agent docs. Aut only sells the API calls.