Phonetic Spell
by Radio & RF Calc in Developer tools
Spell a callsign, code or name with the ICAO/NATO phonetic alphabet, digits included, flagging unspellable symbols.
https://radio-calc.x402tookit.com/phonetic-spell- Price
- $0.02
- per call in USDC
- Uptime
- 64.3%
- last 30 days
- Response time
- 536 ms
- 680 ms slowest 5%
- Last check
- Passed
- 7 h ago, next any minute now
Reliability
Status and outage history · Atom feed · Watch with other listings
How to call it
GET https://radio-calc.x402tookit.com/phonetic-spell
Each call costs $0.02 in USDC on Polygon, paid with the request over x402.
Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.
Example request
From the listing.
GET https://radio-calc.x402tookit.com/phonetic-spell?text=W1AWParameters
| Parameter | Type | Required | Description |
|---|---|---|---|
text | string | Yes | The text to spell (up to 200 characters), for example a callsign such as W1AW |
Example response
The provider's example. We can't check it without paying.
{
"asOf": "2026-10-12T00:54:05.285Z",
"degraded": false,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"input": "W1AW",
"letterCount": 4,
"notChecked": [
"national variants (for example 'Niner' and 'Fife' in radiotelephony pronunciation)",
"accented letters, which are spelled by their base letter",
"…1 more"
],
"reasons": [],
"source": "computed locally (ICAO spelling alphabet)",
"spelled": "Whiskey One Alfa Whiskey",
"summary": "Whiskey One Alfa Whiskey",
"unspellable": [],
"verdict": "SPELLED",
"words": [
"Whiskey",
"One",
"…2 more"
]
}Call it from code
The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.02.
curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://radio-calc.x402tookit.com/phonetic-spell?text=W1AW'
# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://radio-calc.x402tookit.com/phonetic-spell?text=W1AW' \
| grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decodeJavaScript: pay and call
// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";
// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);
// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fradio-calc.x402tookit.com%2Fphonetic-spell
const res = await pay("https://radio-calc.x402tookit.com/phonetic-spell?text=W1AW");
console.log(res.status, await res.text());Python: pay and call
# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client
# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))
with x402_requests(client) as session:
res = session.get("https://radio-calc.x402tookit.com/phonetic-spell?text=W1AW")
print(res.status_code, res.text)Security scan
No findings
We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.
Recent checks
| When | Result | HTTP | Time | Price |
|---|---|---|---|---|
| 7 h ago | Passed | 402 | 540 ms | $0.02 |
| 20 h ago | Passed | 402 | 536 ms | $0.02 |
| 2 days ago | Expected HTTP 402, got 530 | 530 | 137 ms | - |
| 3 days ago | Expected HTTP 402, got 530 | 530 | 106 ms | - |
| 5 days ago | Expected HTTP 402, got 530 | 530 | 94 ms | - |
Show 9 older checks
| 5 days ago | Expected HTTP 402, got 530 | 530 | 338 ms | - |
| 5 days ago | Expected HTTP 402, got 530 | 530 | 160 ms | - |
| 5 days ago | Passed | 402 | 593 ms | $0.02 |
| 6 days ago | Passed | 402 | 530 ms | $0.02 |
| 6 days ago | Passed | 402 | 680 ms | $0.02 |
| 6 days ago | Passed | 402 | 523 ms | $0.02 |
| 6 days ago | Passed | 402 | 500 ms | $0.02 |
| 6 days ago | Passed | 402 | 628 ms | $0.02 |
| 7 days ago | Passed | 402 | 501 ms | $0.02 |