x402

Add USD execution balance with USDC on Base. AI agents can top up through the x402 payment protocol.

Credits Overview

Who pays: Delegated users or agents using Thirdfy services.
When: Chat turns and executions consume balance or free requests.
How: x402 payment protocol. Add USD execution balance with USDC on Base.

See Credits for Users for the full flow and pricing.

x402: Balance and agent payments

Thirdfy agents can add execution balance using the x402 payment protocol. When free requests or paid balance are low, the operator can suggest a top-up, ask for approval, and pay USDC on Base through the dedicated credits tool. External agents can also use the open x402 endpoint directly.

  • USD-first: Users see available balance and charges in USD
  • USDC on Base: Top-ups settle with USDC
  • Operator controlled: Purchases require user approval in Console
  • Open ecosystem: Any compatible agent can discover and use Thirdfy services

How it works

You: "Find the best yield on Base and stake 1000 USDC"

Agent: "You have used today's free requests. I can add
        $25 of execution balance with USDC on Base. Approve?"

You: "Yes"

Agent: ✅ Added $25.00 via x402
       ✅ Balance updated
       ✅ Continuing with the approved task
       
       Payment: $25 USDC on Base

The agent does not claim success until the payment is confirmed and the balance is credited.

Free daily requests

Every user gets 20 free AI chat requests per day. Perfect for testing and light usage.

Top-up amounts

SKUAmount
topup_usd_10$10 USDC
topup_usd_25$25 USDC
topup_usd_50$50 USDC

Custom whole-dollar amounts from $10 to $1,000 use topup_usd_{amount}.

Payment: USDC on Base.

What You Need

Your agent's embedded wallet needs USDC on Base:

You: "Check my USDC balance"
Agent: "You have 50 USDC on Base. That is enough for a $25 top-up."

Getting USDC:

  • Buy on Coinbase and send to Base
  • Bridge from other chains using our bridge tools
  • Swap tokens for USDC

That's It!

Once your wallet has USDC, the agent can top up after you approve the amount.

Security

Agent controls:

  • Detects when credits are needed
  • Suggests a top-up amount
  • Executes USDC payment on Base
  • Claims balance only after payment confirmation

You control:

  • Approve or decline purchases
  • Set wallet spending limits
  • Monitor all transactions on-chain

On-Chain Transparency

Every purchase is recorded on Base:

  • View transaction on Basescan
  • See credits added to account
  • Complete payment history
  • Protected against double-charges

Discovery

Thirdfy is listed on x402scan.com, enabling:

  • Discovery by any AI agent
  • Transparent pricing across ecosystem
  • Open protocol participation
  • Verified service provider status

Any compatible agent can discover and use Thirdfy.

FAQ

Costs are shown in USD in Console. Credits remain the internal ledger unit.

Can I see my balance?

Yes:

You: "How much balance do I have?"
Agent: "You have about $12.34 available and 6 free requests left today."

What if I run out mid-task?

The agent pauses, asks you to approve a USD top-up, and resumes after payment is confirmed.

Can outside agents add balance?

Yes! Any agent can discover Thirdfy on x402scan and purchase credits via our API.

For Developers

Outside developers can integrate Thirdfy's x402 credit system:

Discovery Endpoint:

GET https://api.thirdfy.com/api/v1/credits/x402-metadata

Purchase Endpoint:

POST https://api.thirdfy.com/api/v1/credits/buy-with-x402

Request body: { "sku": "topup_usd_25", "userAddress": "0xYOUR_WALLET_ADDRESS" }

See full API documentation in our x402 API reference

Resources

Troubleshooting
Common errors and how to fix them when integrating with Thirdfy
Credits for Users
Execution balance drives Thirdfy usage. Users see USD balance while credits remain the internal ledger unit.