How to give your AI agent realtime text-to-speech

Way 1

Pay per call with x402 (no sign-up)

x402 is an open standard that puts payment into normal HTTP. The agent asks, the server answers with the price, and the agent's wallet signs a USDC payment and asks again. Best when the agent should pay for itself.

1. 1

   Give the agent a wallet with a little USDC on Base

   In Claude Code, Cursor or Codex, AgentCash sets up the wallet and adds every TollNode node as a tool. Run it once, then send a few dollars of USDC on the Base network to the address it shows.

   terminalCopy

   npx agentcash add https://tollnode.com

2. 2

   Ask your agent to use realtime text-to-speech

   Say what you want in plain words, for example “make an image of …”. The agent picks the Realtime text-to-speech node, sees the price and pays. From a terminal you can call it directly:

   terminalCopy

   npx agentcash@latest fetch https://tollnode.com/api/v1/nodes/speech-realtime -m POST -b '{"text":"Welcome to TollNode. Pay per call, no sign-up."}'

3. 3

   Or pay from your own code

   Any x402 client works. In JavaScript:

   javascriptCopy

   // 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";
   
   const signer = privateKeyToAccount(process.env.AGENT_WALLET_KEY); // a wallet holding USDC on Base
   const pay = wrapFetchWithPayment(fetch, registerExactEvmScheme(new x402Client(), { signer }));
   
   const res = await pay("https://tollnode.com/api/v1/nodes/speech-realtime", {
     method: "POST",
     headers: { "content-type": "application/json" },
     body: JSON.stringify({"text":"Welcome to TollNode. Pay per call, no sign-up."}),
   });
   console.log(await res.json());

4. 4

   What happens on the wire

   The first request comes back as HTTP 402 with the exact price. The client signs and retries with a PAYMENT-SIGNATURE header. TollNode checks the signature, runs Realtime text-to-speech, and collects the payment only if the result is usable. A failed call is never settled.

   see the 402 yourselfCopy

   curl -i -X POST https://tollnode.com/api/v1/nodes/speech-realtime \
     -H 'content-type: application/json' \
     -d '{"text":"Welcome to TollNode. Pay per call, no sign-up."}'

Way 2

Account balance + API key

Load a balance once and use an ordinary API key. Best for apps, servers and teams, or code that can't sign payments.

1. 1

   Create a free account

   Sign up with your email. There is no monthly fee.

2. 2

   Add funds

   On your account page, pick $5, $10, $25 or $50 and confirm in a browser wallet such as Coinbase Wallet or MetaMask. You pay in USDC on Base, with no gas fee to pay.

3. 3

   Create an API key

   Name it after the agent or app that uses it. The key is shown once, so store it as an environment variable (TOLLNODE_API_KEY). You can revoke it at any time.

4. 4

   Call the node

   curlCopy

   curl -X POST https://tollnode.com/api/v1/nodes/speech-realtime \
     -H "Authorization: Bearer $TOLLNODE_API_KEY" \
     -H "content-type: application/json" \
     -d '{"text":"Welcome to TollNode. Pay per call, no sign-up."}'

   javascriptCopy

   const res = await fetch("https://tollnode.com/api/v1/nodes/speech-realtime", {
     method: "POST",
     headers: {
       Authorization: `Bearer ${process.env.TOLLNODE_API_KEY}`,
       "content-type": "application/json",
     },
     body: JSON.stringify({"text":"Welcome to TollNode. Pay per call, no sign-up."}),
   });
   console.log(await res.json());

   pythonCopy

   import os, requests
   
   r = requests.post(
       "https://tollnode.com/api/v1/nodes/speech-realtime",
       headers={"Authorization": f"Bearer {os.environ['TOLLNODE_API_KEY']}"},
       json={"text":"Welcome to TollNode. Pay per call, no sign-up."},
   )
   print(r.json())

   A successful call returns the result plus an x-tollnode-charged-usd header. If the balance is too low you get HTTP 402 with your balance and a top-up link, and nothing is charged. A wrong or revoked key returns 401.

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