Ask. Get a price.
The service returns payment requirements: amount, token, network, recipient, and expiry. Over HTTP, the signal is 402 Payment Required.
Agents do the work.
Now they can get paid.
Price a task in dollars. Pay in USDT on Libre.
No separate gas coin to buy or maintain.
Keep stablecoins or turn earned proceeds into Bitcoin.
Verified on testnet. Production x402 integration is proposed.
Price in dollarsA clear cost for every task
No separate gas coinPay directly in USDT on Libre
Keep your choiceUSDT or optional BTC conversion
01 / The protocol
A price tag for an API call.
x402 lets a service tell an agent what a request costs and how to pay. The agent can handle the payment within its spending policy.
Check. Authorize.
The buyer checks its budget and signs the payment locally. Its SDK submits the authorization with the request. The private key stays with the buyer.
Verify. Deliver.
The payment service verifies and settles the payment under the chosen scheme. The seller returns the work and a receipt tied to that purchase.
Where Libre fits: x402 defines the payment conversation. Libre would provide a USDT payment implementation, with MCP tools for the agent’s wallet. An experimental two-agent payment flow is verified on public testnet. Production integration and upstream x402 interoperability are still pending.
02 / Follow the money
One $19.99 task.
See every step.
Walk through the proposed flow. Change the scenario to see what happens when a payment is short, too large, or outside the buyer’s budget.
An agent needs an answer.
REQUESTILLUSTRATIVE MESSAGES · NOT AN SDK CONTRACT
POST /research/summary request_id: job_demo_001 buyer: buyeragent task: "Summarize this research paper" max_spend_usd: "25.00"
The buyer requests a summary. Its local spending policy allows up to $25.00 for this task. No payment has been made.
STEP 01 / 04
Simulation only. No wallet connection or transaction. Example quotes accept 1 USDT as $1; production quotes must state the conversion policy and expiry. Partial and excess transfers are recovery cases outside the normal exact-payment authorization flow.
Pay from another network
Your buyer does not need
a Libre account.
An agent can receive Bitcoin or Ethereum USDT through its assigned bridge deposit addresses. The sender uses their existing wallet.
Pay with Bitcoin
Send BTC on Bitcoin to the seller’s BTC bridge address. After confirmation and bridge processing, the seller receives BTC on Libre. For a $19.99 task, the payment service would quote the BTC amount, expiry, and any applicable fees.
Pay with USDT on Ethereum
Send ERC-20 USDT on Ethereum to the seller’s assigned USDT bridge address. After bridge processing, the seller receives USDT on Libre. The sender pays Ethereum gas; the recipient needs no separate gas coin on Libre.
Receiving funds is supported; matching them to a task is the next layer.
A shared account address identifies the recipient, not a particular invoice. A payment service must verify the source transaction and Libre credit, securely associate the payment with its buyer and invoice, and reject reuse. A transaction ID alone is not proof that someone paid. Dedicated invoice addresses would require additional provisioning.
External deposits have network confirmation times, bridge minimums, and fee policies. Check the amount expected to arrive before quoting a payment. The recorded demo below tests a USDT transfer within Libre; external invoice settlement has not been tested here.
Look up an account’s bridge addresses ↗ 03 / Verified on public testnet
Two agent wallets.
Zero gas coins. One payment.
Two independent agents completed a paid data-analysis task on Libre testnet. Both wallets held zero LIBRE before and after the USDT payment.
Buyer agent
paybuyuijv14- USDT 25.00 → 5.01
- LIBRE 0 → 0
- Signed a 19.99 USDT payment with its own key
- Verified the seller’s signed result receipt
Seller agent
payseluijv14- USDT 0.05 → 20.04
- LIBRE 0 → 0
- Confirmed payment in irreversible block 260263992
- Delivered one analysis result across every retry
Recovery verified: the buyer recovered a deliberately dropped result, then retrieved the same purchase after a seller restart and three concurrent retries per run. One payment. One fulfillment. Both accounts used the normal initial CPU/NET weights of 1 and 5,120 bytes of RAM.
The work delivered: summarize eight observations. Result: count 8 · minimum 6 · maximum 24 · mean 15. This run waited approximately 2 minutes 56 seconds from payment inclusion to fulfillment after irreversible confirmation.
Recorded September 12, 2026 (PDT). Public testnet and test tokens. The two agents are deterministic software processes with separate wallet keys. The seller’s starting 0.05 USDT is retained from the earlier test. This verifies the experimental Libre payment flow; upstream x402 interoperability and a production service remain to be built.
04 / Your agent’s money
Earn in stablecoins.
Save in Bitcoin, if you want.
Give your agent a USDT working balance for everyday purchases. It does not need to acquire LIBRE as a per-transaction gas token. Fund the wallet through supported bridges, then make many payments on Libre.
A seller can keep earned USDT or choose automatic BTC conversion through Libre’s orderbook. Conversion happens after payment and has its own status.
FUND WALLET → PAY FOR TASKS → MANAGE EARNINGS
External deposits wait for bridge processing.
External deposits wait for bridge processing.
SELLER’S TREASURY / EXAMPLE
199.90 USDT earned
Illustrative proceeds from 10 tasks at $19.99
Keep 199.90 USDT
Retain the proceeds for the agent’s next purchases. No conversion required.
Preference preview. No live balances or market quotes.
05 / From foundation to payment layer
Built on Libre.
Designed for x402.
Libre already exposes wallet and trading tools. This concept adds the payment lifecycle agents need to buy and sell work reliably.
The existing foundation
MCP TOOLS- Pay in USDT without buying a separate gas coin
- Compose BTC and USDT transfers on Libre
- Read balances and request a BTC deposit address
- Read the orderbook, place and cancel orders
- Sign locally and relay signed transactions
The proposed payment layer
TO BUILD- Production Libre x402 client and settlement adapter
- USD quotes, spending policies, and payment receipts
- Retry-safe purchases, reconciliation, and refunds
- Conversion tracking and external payment adapters
How can agents pay without a gas coin?
Libre accounts receive CPU, NET, and RAM resources. A USDT payment does not require a separate native-token gas purchase. Resource limits still apply. Bridge fees, external-network gas, conversion spreads, and service charges are separate from this benefit.
Does x402 already support Libre?
Libre is not listed in x402’s documented network implementations. This page describes a proposed integration. The prototype uses an experimental payment scheme and has completed a two-wallet public-testnet payment. Upstream client integration and conformance testing are still needed before x402 interoperability can be claimed.
What if an agent pays twice?
The proposed payment service binds receipts to the buyer and purchase, deduplicates chain events, and reuses the same job on retries. An additional transfer is recorded as excess, never silently charged for the same work twice.
Can an agent pay in Bitcoin?
BTC would be an optional quoted payment route. An agent can also fund its Libre wallet with BTC and convert to USDT for repeated purchases. Quotes expire; bridge confirmation and conversion are separate steps.
What does “settled” mean?
A transaction being included in a block is different from irreversible settlement. The payment implementation must define its finality policy. External bridge credits and DEX fills are checked separately; a conversion failure does not undo a valid customer payment.
How would metered work be billed?
For work with an unknown final cost, the buyer could authorize a maximum and pay for actual usage. On Libre, that needs a contract or funded balance mechanism that enforces the ceiling. Exact-price USDT payments are the proposed first release.
What about USDC or other networks?
The payment request should name every supported token and network explicitly. External stablecoin adapters could let buyers use their existing wallets. External payment acceptance and moving those funds onto Libre are separate operations.
Useful work deserves a payment.
Start with Libre’s agent tools. Explore the protocol behind the next layer.