71trust / 100

Speech To Text

by Blackwood State Speech to Text in AI models & inference

x402 APIPassing, checked 2 h ago

Use when you need speech to text transcription or translation of an audio file at a public URL. Do not use for audio over 10 MB or speaker labels. Returns JSON with a Whisper transcription of an audio file: text, timed segments and language, or an English translation for 0.005 USDC per megabyte, up to 0.05 USDC per call (clients without upto pay the cap). Asynchronous: the paid call returns a jobId and a free pollUrl; typical job time 20000 ms (p95). Category: Media.

POST
https://x402-gateway.blackwoodstate8.workers.dev/v1/speech-to-text
Price
$0.05
per call in USDC
Uptime
100%
last 30 days
Response time
1.5 s
2.3 s slowest 5%
Last check
Passed
2 h ago, next any minute now

Run a free test callHow to call it

Reliability

All checks passedSome failedAll failedNot checked

Status and outage history · Atom feed · Watch with other listings

How to call it

POST https://x402-gateway.blackwoodstate8.workers.dev/v1/speech-to-text

Each call costs $0.05 in USDC on Base, 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.

POST https://x402-gateway.blackwoodstate8.workers.dev/v1/speech-to-text
content-type: application/json

{
  "url": "https://upload.wikimedia.org/wikipedia/commons/b/bb/Neil_Armstrong_small_step.wav"
}

Parameters

ParameterTypeRequiredDescription
languagestringNoISO 639-1 code of the spoken language, e.g. en or pt (detected when omitted)
taskstringNotranscribe keeps the spoken language; translate returns English (transcribe when omitted) One of: transcribe, translate.
urlstring (uri)YesPublic http(s) URL of the audio file, e.g. https://example.com/talk.mp3 (mp3, wav, ogg, m4a, webm; up to 10 MB)

Example response

The provider's example. We can't check it without paying.

{
  "expiresAt": "2026-01-31T00:00:00.000Z",
  "jobId": "job_00000000000000000000000000000000",
  "pollUrl": "https://gateway.example/v1/speech-to-text/jobs/job_00000000000000000000000000000000",
  "status": "queued"
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.05.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://x402-gateway.blackwoodstate8.workers.dev/v1/speech-to-text' \
  -H 'content-type: application/json' \
  --data-raw '{"url":"https://upload.wikimedia.org/wikipedia/commons/b/bb/Neil_Armstrong_small_step.wav"}'

# 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 - -X POST 'https://x402-gateway.blackwoodstate8.workers.dev/v1/speech-to-text' \
  -H 'content-type: application/json' \
  --data-raw '{"url":"https://upload.wikimedia.org/wikipedia/commons/b/bb/Neil_Armstrong_small_step.wav"}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode
JavaScript: 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 $0.05 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.05" });
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 $0.05 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fx402-gateway.blackwoodstate8.workers.dev%2Fv1%2Fspeech-to-text&method=POST
const res = await pay("https://x402-gateway.blackwoodstate8.workers.dev/v1/speech-to-text", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "url": "https://upload.wikimedia.org/wikipedia/commons/b/bb/Neil_Armstrong_small_step.wav"
  }),
});
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 $0.05 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.05"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://x402-gateway.blackwoodstate8.workers.dev/v1/speech-to-text",
        json={
            "url": "https://upload.wikimedia.org/wikipedia/commons/b/bb/Neil_Armstrong_small_step.wav",
        },
    )
    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

WhenResultHTTPTimePrice
2 h agoPassed4021.8 s$0.05
5 h agoPassed4021.7 s$0.05
8 h agoPassed4022.3 s$0.05
12 h agoPassed4021.5 s$0.05
15 h agoPassed4021.3 s$0.05
Show 8 older checks
18 h agoPassed4021.3 s$0.05
21 h agoPassed4021.1 s$0.05
26 h agoPassed4022.2 s$0.05
31 h agoPassed4022.3 s$0.05
36 h agoPassed4021.4 s$0.05
42 h agoPassed402853 ms$0.05
47 h agoPassed4021.4 s$0.08
2 days agoPassed4022.1 s$0.08

History

18 Oct 2026Price changed from $0.08 to $0.05