The full upstream README, mirrored here for reference. Install config, tool schemas, adoption signals, and an original overview live on the VouchSpec Agent Skill Evidence listing page.
VouchSpec is the provisional public-beta name for an independent evidence index for exact Agent Skill versions. The name passed a $0 obvious-conflict screen; it has not received formal legal or trademark clearance.
The current Stage A catalog contains 25 deliberately selected public Agent Skills across 12 GitHub repository owners. Every entry is pinned to a full Git commit and exact directory digest, statically inspected without executing artifact code, wrapped in a DSSE v1.0.2 envelope, and signed with Ed25519. A separate root key signs the machine-readable lifecycle feed.
This is evidence, not a safety certification. Six of the 25 real-world skills fail at least
one current structural rule; they remain indexed with the failure evidence and are not
labeled STRUCTURE_VALIDATED.
The static distribution returns the exact checked-in signed bytes with CORS enabled and
rejects writes. Download the signed index, filter it locally, then retrieve a receipt by ID
from catalog/public/receipts/. For immutable retrieval, replace main with catalog snapshot
4404b7a9a2d3dc45b621ea694d2ca7ad666b9898. The out-of-band Gist is separate from the
repository but shares its GitHub account, so an account-level compromise still requires a
new trusted channel.
Stage C is not a prerequisite for Stage A or B. No arbitrary upload route exists in the Stage A server or MCP tools.
The public publisher-CI demo shows the complete
trusted-workflow path: immutable action pins, exact-commit inspection, two GitHub artifact
attestations, downloadable evidence, and independent gh attestation verify commands. The
latest verified matrix run
passes both a structural-pass case and an intentional structural-failure case. Its four
downloaded evidence files independently verified with gh attestation verify. The demo is
operator-controlled and is not counted as external adoption.
Use the action at its immutable evidence-preserving snapshot:
The action emits a receipt draft and publisher/workflow binding for both structural passes and explicit structural failures. See the full pinned workflow, permissions, verification, and troubleshooting guide.
Receipts use explicit labels, never a generic VERIFIED badge:
DIGEST_PINNEDSTRUCTURE_VALIDATED (only when the structural profile passes)STATIC_INSPECTION_COMPLETEDINDEPENDENT_STATIC_SCAN (only for the curated operator-run profile)PUBLISHER_CI_ATTESTED, SANDBOX_BEHAVIOR_OBSERVED, and TASK_EVALUATED are reserved for
separate evidence that has actually been produced. Static inspection never implies them.
The verifier authenticates the exact decoded receipt bytes before parsing JSON, validates the receipt schema and inner consistency digest, then optionally applies the root-signed lifecycle feed.
Lifecycle results are CURRENT, SUPERSEDED, EXPIRED,
REVOKED_EVALUATOR_DEFECT, REVOKED_KEY_COMPROMISE, or the conservative
SIGNATURE_VALID_LIFECYCLE_UNKNOWN. The signing key ID is only a lookup hint; the public
JWK must be obtained or pinned through an independently trusted path.
Available GET routes:
/health/v1/index (issuer-signed DSSE index envelope)/v1/quote?operation=... (price/availability response; paid orders remain disabled)/v1/receipts?q=...&repository_owner=...&limit=.../v1/receipts/{receipt_id}/v1/receipts/{receipt_id}/status/v1/lifecycle/v1/keys/root/v1/keys/issuerAll POST requests receive 405 read_only. The built-in server is connection-bounded,
deadline-enforced, and loopback-only; a public deployment must place it behind a managed TLS
proxy with platform ingress limits. Each process serves one fully verified immutable catalog
snapshot; deploy a new lifecycle/index generation by restarting the process. The highest
observed root-feed sequence and its payload digest are persisted with a cross-process lock.
The local catalog price-card route reports the commercial price hypothesis without accepting an order. For a strict request-specific local preview:
The preview validates the same request shape used by the managed API. The public sandbox price
is deliberately faucet-sized at 1.00 test USDC. Full agent-market research rejected the
earlier $49 idea; the commercial mainnet launch cohort is an unvalidated 0.25 USDC per fresh
validation, with the predeclared evidence gates in PRICING.md.
The commercial service at https://vouchspec.plyrium.com is machine-only and has no card form,
hosted checkout, account portal, or human approval step. An agent sends the strict immutable
public-GitHub request to POST /api/vouchspec/v1/validate, receives an x402 v2 challenge for
exactly 0.25 USDC on Base, signs it, and retries with PAYMENT-SIGNATURE. Successful
settlement returns one-time delivery credentials; the scheduled isolated worker then produces
the signed, content-addressed receipt. Discovery and health are public, and the Streamable HTTP
MCP endpoint exposes read-only contract discovery. The same purchase contract is published as
OpenAPI, llms.txt, A2A, x402, and a draft/proposal ARD catalog so agents can enter through the
protocol they already index. Remedy execution remains disabled and is not a prerequisite for
accepting or fulfilling ordinary paid validations.
The public service at https://vouchspec-sandbox.plyrium.com has no card form, hosted checkout,
or human approval step. An agent:
vouchspec-stage-b-2026-07-14 at
POST /api/vouchspec/v1/tenants and stores the one-time tenant bearer key;POST /api/vouchspec/v1/quotes with
Authorization and a unique Idempotency-Key;POST /api/vouchspec/v1/orders and stores the returned delivery token;purchase_path, reads the x402 v2 PAYMENT-REQUIRED challenge, signs the
exact 1.00 test-USDC payment on Base Sepolia, and retries with PAYMENT-SIGNATURE;Successful envelopes are also published at a content-addressed unauthenticated URL. Agents may
cache and share those immutable bytes. Invalidation is intentionally separate: check the
corresponding no-store /status URL each time the receipt is used for a new decision. The
machine-readable discovery document contains all route templates,
headers, network, price, trust, caching, and product-boundary fields.
The hosted proof is owner-controlled and testnet-only, so it demonstrates mechanics but counts as no customer, request, buyer, or revenue. See the Stage B operating boundary, payment flow, managed deployment boundary, and refund policy, and mainnet remedy operations.
The repository still includes a loopback harness for regression and security testing. It stores keyed credential digests, never plaintext tokens, and binds each quote and order to one opaque tenant. Generate two distinct 32-byte secrets with an approved secret manager, expose their hex values only to the process, then provision one local sandbox credential:
The local API binds to 127.0.0.1, has no CORS allowance, and exposes authenticated quote, order,
status, signed-result, capability-rotation, and capability-revocation routes. Its fake payment
rail never settles and every resulting order remains counts_for_goal: false.
An explicitly nonsettling Stripe-test adapter remains available for regression coverage only. It is not the VouchSpec launch rail and is not exposed by the managed agent service:
Do not expose that built-in listener directly. Mainnet activation uses x402, separate live state and secrets, and the live gates in the deployment boundary.
Remote agents can discover the commercial managed contract through the stateless Streamable HTTP endpoint
at https://vouchspec.plyrium.com/api/vouchspec/v1/mcp. It exposes only
get_vouchspec_discovery: an anonymous, read-only tool that returns public route, price, x402,
receipt, cache, and invalidation instructions. It cannot submit artifacts, fetch repositories,
settle payments, or read private data. Paid validation remains on the managed x402 REST route.
Agents that support the open Agent Skills format can add the repository's exact verify-before-install workflow directly:
The skill is also published through the well-known machine endpoint above. It discovers the live
contract before acting, checks existing signed evidence first, and purchases a fresh 0.25 USDC
validation only when the calling agent already has an x402 wallet and explicit spending authority.
If either is absent it returns payment_required; there is no human checkout or human handoff.
The checked-in server.json describes this remote endpoint for the official MCP Registry under
the active name io.github.mordiaky/vouchspec. Publication uses GitHub OIDC from a main-only
manual workflow, so it needs no portal login, phone code, or dedicated Registry secret.
For agents that prefer a locally pinned catalog, the stdio server remains available:
Public install:
Tools are search_receipts, get_receipt, get_receipt_status,
get_verification_material, and get_price_quote. They accept identifiers, search text,
and named price-card operations only, not artifact content. This local read-only MCP does not
place paid orders; agents use the managed x402 API for fresh validation.
Development install:
The compatibility command and Python package name capabilityproof remain available
alongside the public vouchspec command.
Local inspection never installs, imports, renders, or executes artifact content. The checked-in catalog builder accepts only the curated manifest and public HTTPS GitHub repositories at full 40-character commits. Collection is keyless, issuer signing is a separate no-network phase, and recovery-root lifecycle signing is a separate offline phase. Encrypted private keys stay outside this repository; only RFC 8037 public JWKs are published.
See methodology, the receipt schema, and the threat model.