Pin
One public GitHub repository, full commit, and explicit Agent Skill directory. No branches, tags, private sources, or uploads.
public evidence index · x402 sandbox live
Evidence
before execution.
VouchSpec gives agents a signed record of what was checked for one exact Agent Skill version—before an install decision or connection.
Static evidence ≠ universal safety certification
capability-receipt.dsse.jsonCURRENT
artifactgithub.com/example/agent-skills
commit9f20a1…c773d4
pathskills/pdf-extract
DIGEST_PINNED
STRUCTURE_VALIDATED
STATIC_INSPECTION_COMPLETED
limitations / artifact content not executed; publisher identity not established
sha256: 01a8…44fcEd25519 ✓
25
exact skill versions
12
repository owners
DSSE
signed envelopes
Ed25519
public verification
The trust boundary
A receipt is a chain of claims, not a badge.
Each label names the evidence that actually exists. Failures remain visible and signed. “Verified” is never used as a shortcut for “safe.”
Constrain
The exact tree is size-bounded. Static inspection runs in a read-only, no-egress worker. Artifact scripts are not executed.
Sign
The receipt binds source coordinates, content digest, checks, limits, timestamp, and evidence labels into an Ed25519-signed DSSE envelope.
Verify
Your agent verifies exact bytes, the published key, and lifecycle status before using the evidence in an install policy.
API beta
Quote first.
Pay only for a fresh run.
An agent creates an API tenant, submits one immutable public source request, receives the exact 1 test-USDC sandbox quote, and pays another API through x402. There is no human checkout path.
- Opaque bearer key stored only as a keyed digest
- Every quote, order, and payment bound to one tenant
- Order-specific delivery capability can rotate or revoke
- Durable x402 claims prevent replay and concurrent settlement
agent / x402 Base Sepolia
No account page. No card form. No checkout session.
The buyer is an authenticated agent. The purchase is one HTTP 402 negotiation and an onchain USDC settlement.
- 01RegisterPOST /api/vouchspec/v1/tenants accepts the current machine-readable terms and returns one opaque tenant bearer key.
- 02QuotePOST /api/vouchspec/v1/quotes pins one public GitHub repository, full commit, explicit skill path, and a 1 test-USDC maximum.
- 03OrderPOST /api/vouchspec/v1/orders returns an order-scoped delivery capability and the x402 purchase resource.
- 04PayGET the purchase resource. Use PAYMENT-REQUIRED to sign exactly 1 test USDC, then retry with PAYMENT-SIGNATURE.
- 05RetrieveRetrieve once with both credentials, then cache or share the public content-addressed DSSE envelope and check its live status.
HTTP exchange
GET /api/vouchspec/v1/orders/{order_id}/purchase
Authorization: Bearer {tenant_api_key}
X-VouchSpec-Delivery-Token: {delivery_token}
HTTP/1.1 402 Payment Required
PAYMENT-REQUIRED: {base64_payment_requirements}
GET /api/vouchspec/v1/orders/{order_id}/purchase
Authorization: Bearer {tenant_api_key}
X-VouchSpec-Delivery-Token: {delivery_token}
PAYMENT-SIGNATURE: {agent_signed_payment}
HTTP/1.1 202 Accepted
PAYMENT-RESPONSE: {settlement_proof}Base Sepolia is a non-revenue integration sandbox. The commercial $49 hypothesis remains fail-closed until mainnet remedies, environment separation, and actual cost accounting pass.
Free path
Cache the receipt. Share it. Verify it yourself.
The public catalog, content-addressed receipts, lifecycle status, GitHub Action, verifier, schemas, keys, and methodology are open. Payment buys a fresh constrained run—not exclusive access to its evidence.