The price comes first.

Each tool quotes its price over x402 before it runs. Your agent pays from a capped budget, only when the result comes back.

Ask Siro See all 67 prices

$0.02per call

Price list.

Nothing is charged here. You sign in Ask, after your yes.

Sign, Run and Settle: in Ask, after your yes.

Per call$0.02 of $0.10

Today$0.02 of $1.00

x402 v2 · POST /v1/prediction-read

Two rails, one route.

The mark is the safety rule. One rail is the cap per call, the other the cap per day, and every payment rolls between them. A quote that would cross a rail is refused before anything is signed.

The Siro S milled into a brushed aluminium plate as two grooves, with a chrome ball resting in the upper groove.
  1. The ball: one payment
  2. This rail: the cap per call
  3. The channel: the route, Brief to Settle
  4. That rail: the cap per day

Turn the cap. See what still fits.

A per-call cap is the most a single payment may cost. Siro checks it on your device before anything is signed.

$0.10a call

Catalog prices, per calllog scale · from the catalog

Use this cap in Budget

Asking is free. Paying waits for your yes.

You

Draw a steel ball rolling along an S-shaped groove milled into brushed aluminium, studio light

Chat is free. The agent reads the brief and picks a tool from the catalog.

Siro

Nano Banana 2.1 can draw that: one 1K image, quoted at $0.045. Approve the quote and I will run it.

No tool has run yet, so nothing has been charged.

Quote

Nano Banana 2.1Google · /v1/nano-banana-2-1

$0.045per call

USDG on Robinhood Chain

Within a new wallet's default caps

Specimen. These keys are live in Ask.

The price is the tool's own 402 quote. Approve signs that exact amount; over your cap, Siro refuses before signing.

Try this in Ask

Close-up of the chrome ball resting in a groove milled into brushed aluminium.

No result, no charge.

Siro runs the tool first and settles your payment only when a result comes back. If the tool fails, the signed payment is never settled and nothing moves.

ActivityGET /api/ledger

Every settlement, in Activity

Three ways in. One price list.

Plain HTTP, the siro CLI and an MCP server all price from the same catalog file, so a tool costs the same wherever your agent calls it.

for prediction-read

HTTP

curl -i -X POST https://siroagent.com/v1/prediction-read \
  -H 'content-type: application/json' \
  -d '{"market":"fed interest rates"}'

The 402 puts the price in the payment-required header. Sign accepts[].amount for one network, send the same request again with a payment-signature header, and the result comes back with a receipt.

CLI

npm i -g https://siroagent.com/cli/siro.tgz
siro init
siro limits --per-payment 0.10 --per-day 1
siro call prediction-read market='fed interest rates'

siro init makes a key and encrypts it with your password. siro limits sets the caps the CLI checks before it signs anything.

MCP

{
  "mcpServers": {
    "siro": {
      "command": "siro",
      "args": [
        "mcp"
      ],
      "env": {
        "SIRO_PASSWORD": "your wallet password"
      }
    }
  }
}

For Claude, Cursor or any MCP client. The local server runs on the CLI wallet and pays inside its caps. Remote, with nothing to install: https://siroagent.com/mcp lists the catalog for free, and its siro_call answers with the 402 terms until your client signs.

The response your agent getsnothing captured
Capturing the live 402 needs JavaScript. The HTTP curl gets the same answer.

Start at $0.10 a call and $1.00 a day.

Ask Siro Set a budget