A compensation, attribution, and metering layer for authored AI Skills — demonstrated below against a live endpoint.
ALL PAYMENTS: TESTNET USDC — PLAY MONEY, NO REAL FUNDSThe skill optimizing-claude-code-prompts runs hosted behind a gate — the Collar — at neverhandedover.com. Ask it to work without payment and it answers with HTTP 402 Payment Required and machine-readable terms. Nothing runs, nothing leaks.
POST /api/invoke/optimizing-claude-code-prompts HTTP/1.1 Host: neverhandedover.com Content-Type: application/json {"input": "help me tighten this prompt"}
HTTP/1.1 402 Payment Required
Live: your browser just received this from the production endpoint.
Captured 2026-07-16. The endpoint is live but doesn't yet send CORS headers, so browsers can't call it directly — the curl above shows you the identical response from your own terminal in one paste.
| field | value | meaning |
|---|---|---|
status | 402 | the Collar refuses to run the Skill without a settled payment |
scheme | exact | fixed price per Invocation |
network | base-sepolia | testnet — play money |
maxAmountRequired | 250000 | 0.25 testnet USDC (USDC has 6 decimals) |
payTo | 0x2500…F189 | the Collar's receiving address |
asset | 0x036C…CF7e | the USDC contract on Base Sepolia |
maxTimeoutSeconds | 60 | how long the signed payment stays valid |
The entire client-side footprint of this protocol is: answer HTTP 402 with a signed payment and retry. No SDK on the paying side — a wallet and an HTTP client are enough. Claude Code, a cron job, and curl are all valid Wielders.
Request → 402 → signed payment → verify, settle, run, meter. Steps 2–4 below are simulated in your browser — a public page holds no signing key — but the payload shapes match the live endpoint's protocol byte for byte, and two real testnet settlements are linked at the end.
POST /api/invoke/optimizing-claude-code-prompts HTTP/1.1 Host: neverhandedover.com {"input": }
The Collar answers 402 with the terms from §1. Nothing has run; the Skill's content never appears on the wire.
The Wielder signs an EIP-3009 TransferWithAuthorization for 0.25 testnet USDC — gasless and single-use. This one is simulated: the signature is random bytes, the payer address invented.
X-PAYMENTPOST /api/invoke/optimizing-claude-code-prompts HTTP/1.1 Host: neverhandedover.com X-PAYMENT: (base64 of step 2) {"input": }
The Collar verifies the signature, settles on Base Sepolia via the x402 facilitator, mints the single-use Execution credential, runs the Skill, records the Invocation, and returns the output with a settlement receipt:
HTTP/1.1 200 OK X-PAYMENT-RESPONSE:
Receipt above is simulated — two real testnet settlements from this exact endpoint: tx 1 · tx 2. The Wielder receives the Skill's output — never the Skill.
A Derivative owes royalties to every Skill in its ancestry, credited per Invocation. The chain below is the protocol repo's actual Phase-0 fixture chain: demo-base → demo-child → demo-grandchild. The Wielder invokes the grandchild; the meter credits the whole line.
Credits accumulate in the Collar's meter and are claimable on demand — settlement is batched and eventually-consistent, decoupled from the per-Invocation payment gate. Split model is illustrative: each Skill passes of what it receives to its immediate ancestor. All amounts are testnet USDC (play money); royalty claims are non-transferable in the closed modes.
Under work-for-hire, an authored Skill — a Claude Code skill, a plugin, an agent definition — is handed over once, and its author captures none of the ongoing value. This protocol keeps the artifact behind the Collar and meters every use. Compensation, attribution, and metering as infrastructure.
| term | meaning |
|---|---|
| Skill | a natively-digital, reusable work artifact encoding specialized capability — the unit of value |
| Creator | the party that authors a Skill and holds the residual economic claim on its use |
| Wielder | the party that invokes a Skill; any client that can pay qualifies — its whole footprint is answer 402, pay, retry |
| Beneficiary | the party realizing downstream value from the Wielder's work (typically the employer); funds the payment |
| Collar | the hosted gate around a Skill's execution: sole API-key holder, x402 resource server, off-chain meter — the single trusted component |
| Invocation | one metered use of a Skill via its hosted execution — the billable event |
| Execution credential | single-use authorization minted by the per-Invocation payment; no credential, no run |
| Derivative | a Skill built on existing Skills; each Invocation credits every ancestor |
| Royalty claim | entitlement to a share of a Skill's Invocation revenue — co-holdable, fractional, non-transferable in the closed modes |
Go deeper: protocol repo (Apache-2.0) · manifesto & live demo · real settlements tx 1 / tx 2 · x402 (HTTP-native payments, Linux Foundation) · testnet USDC from the Circle faucet