Speech To Text
by Blackwood State Speech to Text in AI models & inference
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.
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
Reliability
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
| Parameter | Type | Required | Description |
|---|---|---|---|
language | string | No | ISO 639-1 code of the spoken language, e.g. en or pt (detected when omitted) |
task | string | No | transcribe keeps the spoken language; translate returns English (transcribe when omitted) One of: transcribe, translate. |
url | string (uri) | Yes | Public 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 --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 $0.05 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
| When | Result | HTTP | Time | Price |
|---|---|---|---|---|
| 2 h ago | Passed | 402 | 1.8 s | $0.05 |
| 5 h ago | Passed | 402 | 1.7 s | $0.05 |
| 8 h ago | Passed | 402 | 2.3 s | $0.05 |
| 12 h ago | Passed | 402 | 1.5 s | $0.05 |
| 15 h ago | Passed | 402 | 1.3 s | $0.05 |
Show 8 older checks
| 18 h ago | Passed | 402 | 1.3 s | $0.05 |
| 21 h ago | Passed | 402 | 1.1 s | $0.05 |
| 26 h ago | Passed | 402 | 2.2 s | $0.05 |
| 31 h ago | Passed | 402 | 2.3 s | $0.05 |
| 36 h ago | Passed | 402 | 1.4 s | $0.05 |
| 42 h ago | Passed | 402 | 853 ms | $0.05 |
| 47 h ago | Passed | 402 | 1.4 s | $0.08 |
| 2 days ago | Passed | 402 | 2.1 s | $0.08 |
History
| 18 Oct 2026 | Price changed from $0.08 to $0.05 |