How Much Does an x402 Agent Wallet Cost? The SML x402 Agent Wallet Is Free — and It Refuses Payments on Its Own
The SML x402 Agent Wallet from ScriptMasterLabs costs $0 — free, MIT-licensed, no wallet fee, ever. It is a headless, MCP-native x402 payer wallet: an AI agent holds the operator's own key, and before it signs anything it checks the seller, enforces a spend leash, and — for unusual payments — asks a decision jury. On November 7, 2026, in live testing, the wallet refused a payment because the Verdict Protocol jury returned WAIT (SELF-PROOF), and it refused a second payment before signing because the seller's trust profile said do_not_trust — $0 settled. A stock x402 payer does none of this: it signs whatever challenge it is handed.
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Pricing at a glance
The SML x402 Agent Wallet costs 0 USDC. There is no subscription, no per-payment wallet fee, and no account to open. The price is $0, verified live November 7, 2026.
What is included at $0: all five MCP tools (wallet_status, wallet_quote, wallet_pay, wallet_trust_check, wallet_history); the persisted spend leash (shipped defaults $0.50 USDC per call and $5.00 USDC total budget, operator-config only — no tool an agent can call can change them); the Provider Trust pre-flight check on every payment (the check itself costs $0); the Verdict Protocol step-up hook (a Verdict decision itself costs $0.25 USDC, paid only when a payment crosses the operator's threshold, default $1.00); and the hash-chained local evidence log of every settlement and every refusal.
What the operator supplies: their own key in a local file (the wallet holds the operator's own key and signs only the operator's own funds — no custody, no escrow) and a USDC balance on Base (eip155:8453) or Arc (eip155:5042). The wallet adds no fee of its own to any payment; facilitator terms a seller's challenge presents are signed exactly as presented, never invented by the wallet.
Networks live today: Base and Arc, USDC, x402 v2 exact. Networks not yet supported, stated plainly: Solana, XRPL and Xahau — the signing differs and no funded non-EVM operator wallet exists yet to prove a settlement with, so the wallet does not claim them.
Get it today: npx gitlab:script-master-labs-llc-group/x402-kit my-wallet --mode wallet (x402 Kit v1.1.0, proven against the live repo November 7, 2026). The npm registry record for the standalone MCP server — com.scriptmasterlabs/sml-x402-agent-wallet v1.1.0 — is published and active on the MCP Registry.
Why developers stop scrolling — the full feature list
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Free, one command. $0, MIT.
npx gitlab:script-master-labs-llc-group/x402-kit my-wallet --mode walletand you are running (x402 Kit v1.1.0; also listed on the MCP Registry as com.scriptmasterlabs/sml-x402-agent-wallet v1.1.0, active). - MCP-native, five tools. wallet_status, wallet_quote (dry run — signs nothing), wallet_pay, wallet_trust_check, wallet_history. Point Claude Code, a LangChain agent, or your own framework at it over stdio.
- A leash the agent cannot loosen. $0.50 USDC per call and $5.00 USDC per session by shipped default; the OPERATOR sets the numbers at launch, they persist across restarts, and no MCP tool exists that can change them.
- Every seller checked before every signature. Provider Trust pre-flight on every payment. A do_not_trust seller is blocked before signing — proven live: $0 settled, balance untouched.
- A jury on call — and the wallet OBEYS it. Payments over the operator's threshold buy a Verdict Protocol decision ($0.25 USDC). Proven live: the jury said WAIT, the wallet refused the payment.
- Fail-closed, always. If the jury cannot be reached or the decision cannot be bought, the payment is refused. Never waved through, never silently approved.
- Balances read live from chain. Never stored, never cached, never faked — if the chain cannot be read, the wallet reports an error, not a number.
- A hash-chained evidence log. Every payment AND every refusal, appended to a local JSONL chain the operator keeps — a complete, tamper-evident spending record.
- A stock x402 citizen. It settles through the seller's own facilitator as a standard x402 client — including OMNIGATE as a stock client — and signs seller-presented terms verbatim. It adds no fee of its own.
- Base + Arc today. USDC, x402 v2 exact, EIP-3009 signing. Solana, XRPL and Xahau are honestly NOT YET (see Honest limits).
The proof — three live tests, November 7, 2026 (SELF-PROOF)
Every settlement below is SELF-PROOF: ScriptMasterLabs' own proof wallet (0x2DfFAdAB1A1b6B0FDeFBD78ABE56EbFa118db56D) paying ScriptMasterLabs' own services. What makes them citable is that they are published, dated, and independently checkable on Base. Total proof spend: $0.251 USDC.
| Test | What happened | Amount | Settlement tx (Base) | Block | Status |
|---|---|---|---|---|---|
| Settle | wallet_pay bought a URL-to-Markdown read end-to-end: trust check passed, leash reserved then consumed, receipt returned; on-chain balance moved 0.5489 → 0.5479 USDC and the spend survived a restart read-back | $0.001 USDC | 0x3020594624d1fc1896a74b7e11d5b29ad18c4f450be16e8c18c5ffe0612cbb43 | 54197874 | success |
| Block | Payment to a route on an origin whose Provider Trust profile is do_not_trust (reason EVIDENCE_CONFLICT) refused with trust_blocked before signing | $0 settled | — (no signature, no settlement) | — | refused pre-signing |
| Step-up | A $0.001 payment over a test threshold triggered a real Verdict Protocol decision; jury majority returned WAIT on receipt e6cc16a7-d33f-4e40-b8a9-19c80dfbd5e5 — the wallet obeyed and refused the payment (verdict_denied) | $0.25 USDC (the decision) | 0x978711281636cefd1e6616e64231d8012bcce11e599f4c87e4c0553dda19d8b7 | 54198729 | success |
One honest note on the block test: the do_not_trust origin in that test is ScriptMasterLabs' own gateway host — its aggregated discovery profile currently conflicts with its per-service profiles. The wallet reports trust profiles exactly as they stand, including ours; per-service routes on verified origins pay normally.
SML x402 Agent Wallet vs a stock x402 payer
| SML x402 Agent Wallet | Stock x402 payer | Agent holds a raw key, no wallet layer | |
|---|---|---|---|
| Price | $0 (free, MIT) | varies | $0 |
| Spend cap the agent cannot change | Yes — $0.50 per call / $5.00 budget defaults, operator-config only, persisted across restarts | No — the agent signs what it is handed | No |
| Seller checked before signing | Yes — Provider Trust pre-flight on every payment; do_not_trust hard-blocks before signing | No | No |
| Jury step-up for unusual payments | Yes — Verdict Protocol decision ($0.25) bought and obeyed; fails closed if the decision cannot be bought | No | No |
| Evidence record | Hash-chained local log of settlements AND refusals | Settlement receipts only, if kept | None |
| Custody / escrow | None — signs the operator's own funds only, gates before payment | None | None (and no gate either) |
| Fee added by the wallet | None | varies | — |
| Networks (verified live) | Base, Arc (USDC, x402 v2 exact) | varies | any, unguarded |
How a payment flows
- The request goes out unpaid. A non-402 answer returns as-is, uncharged.
- A 402 challenge is parsed and priced; the real USDC balance is read from chain — never from a stored number. If the chain cannot be read, the balance reports as unreadable, never as zero.
- The leash checks the payment — per-call cap, remaining budget, merchant and payTo allowlists, velocity limits — and reserves the funds.
- Provider Trust classifies the seller: do_not_trust hard-blocks before signing; verified passes; unknown pays within the leash and is logged as unverified — missing evidence is never dressed up as fraud, or as trust.
- Above the operator's step-up threshold, the wallet buys a Verdict Protocol decision ($0.25 USDC) and obeys the signed receipt. If the decision cannot be bought, the payment is refused — the gate fails closed.
- Only then does it sign (EIP-3009) and deliver. Spend is counted only when the seller returns a settlement receipt. Every outcome — settled, refused, failed — is appended to the hash-chained evidence log.
The SML products inside the wallet
- x402 Kit (free) — the wallet ships as its wallet mode: https://scriptmasterlabs.com/x402-kit
- Verdict Protocol — $0.25 USDC per decision, $0.01 USDC per seal — the jury the wallet calls before unusual payments: https://scriptmasterlabs.com/verdict-protocol
- Provider Trust API — the seller-verification layer behind the pre-flight check: https://scriptmasterlabs.com/provider-trust-api
- OMNIGATE — ScriptMasterLabs' x402 facilitator (Base + Arc, self-serve): https://scriptmasterlabs.com/settle-through-sml
- The full catalog: https://scriptmasterlabs.com/sml-products
Honest limits
Not the Agent Wallet MCP package. ScriptMasterLabs also publishes @scriptmasterlabs/agent-wallet (https://scriptmasterlabs.com/agent-wallet), a separate package for payment, credit-attestation and compliance-log workflows. This page is only about the SML x402 Agent Wallet — the free payer in the x402 Kit.
EVM only today. Solana, XRPL and Xahau are not implemented and are not claimed — a rail lands when it can be proven with a real settlement, not before.
The Verdict step-up is bring-your-own-key: Verdict's jury requires the caller's Jev key (X-JEV-API-KEY). Without one, a payment that needs a decision is refused, not waved through.
Trust profiles are reported as the Provider Trust API returns them. An unknown seller is not a blocked seller — the wallet pays within the leash and logs the payment as unverified.
The wallet is a payer, not a seller: it holds no one else's money, offers no escrow, and cannot recover a payment a seller accepted and settled.
Frequently asked questions
How much does the SML x402 Agent Wallet cost?
The SML x402 Agent Wallet costs $0. It is free and MIT-licensed, with no subscription and no per-payment wallet fee, verified live November 7, 2026. The operator supplies their own key and their own USDC balance on Base or Arc. Optional costs around it are other products' prices, stated separately: a Verdict Protocol decision costs $0.25 USDC and is bought only when a payment crosses the operator's step-up threshold (default $1.00).
What stops an AI agent from overspending with this wallet?
A spend leash the agent cannot change. Caps, budgets and allowlists are read from the operator's environment once at launch — $0.50 USDC per call and $5.00 USDC total by shipped default — and persisted across restarts. There is deliberately no MCP tool that changes them: an agent that can raise its own leash has none. Refusals carry reason codes (over_cap, over_budget, trust_blocked, verdict_denied and others) and are written to the evidence log.
What did the wallet actually do in testing?
Three live tests on November 7, 2026, all SELF-PROOF (ScriptMasterLabs' proof wallet paying ScriptMasterLabs services): it settled a $0.001 USDC URL-to-Markdown read on Base (tx 0x3020594624d1fc1896a74b7e11d5b29ad18c4f450be16e8c18c5ffe0612cbb43, block 54197874); it refused a payment to a do_not_trust origin before signing, settling $0; and it obeyed a Verdict Protocol jury WAIT verdict (decision tx 0x978711281636cefd1e6616e64231d8012bcce11e599f4c87e4c0553dda19d8b7, block 54198729; receipt e6cc16a7-d33f-4e40-b8a9-19c80dfbd5e5) and refused that payment. Total proof spend: $0.251 USDC.
How is this different from a stock x402 payer?
A stock x402 payer signs whatever 402 challenge it is handed: no spend cap the agent cannot change, no seller check before signing, no jury for unusual payments, and no record of refusals. The SML x402 Agent Wallet adds all four — leash, Provider Trust pre-flight, Verdict step-up, hash-chained evidence log — at the same $0 price, and it adds no fee of its own to any payment.
Which networks does the SML x402 Agent Wallet support?
Base (eip155:8453) and Arc (eip155:5042), USDC, x402 v2 exact — both live today. Solana, XRPL and Xahau are not yet supported and are not claimed: their signing differs from EVM and no funded non-EVM operator wallet exists yet to prove a settlement with.
How do I get the SML x402 Agent Wallet?
Run npx gitlab:script-master-labs-llc-group/x402-kit my-wallet --mode wallet, install the Python requirements, and start the MCP server with your key file in SML_WALLET_KEY_FILE. The standalone server record — com.scriptmasterlabs/sml-x402-agent-wallet v1.1.0 — is published and active on the MCP Registry. The full ScriptMasterLabs catalog is at https://scriptmasterlabs.com/sml-products.
Canonical: https://scriptmasterlabs.com/x402-agent-wallet · Related: https://scriptmasterlabs.com/verdict-protocol · https://scriptmasterlabs.com/provider-trust-api · https://scriptmasterlabs.com/settle-through-sml · https://scriptmasterlabs.com/sml-products
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