# VouchSpec Agent Skill Evidence [Health: Active]

**Category:** 💰 Finance & Fintech  
**Repository:** https://github.com/mordiaky/vouchspec  
**GitHub Stars:** 1  
**Views:** 0  
**Installs:** 0  
**Upvotes:** 0  
**Directory Page:** https://allmcps.com/mcp/vouchspec-agent-skill-evidence

## Description
Read-only discovery for exact-commit Agent Skill validation, x402 payment, and signed receipts.

## Claude Desktop Quick Installation
Install path detected from listing signals. Uses `npx` (confidence: high):

```json
"mcpServers": {
  "vouchspec-agent-skill-evidence": {
    "command": "npx",
    "args": ["-y","skills"]
  }
}
```

## Documentation & README

# VouchSpec

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`.

## Public Stage A distribution

- Repository and install source: <https://github.com/mordiaky/vouchspec>
- Machine-readable discovery: <https://raw.githubusercontent.com/mordiaky/vouchspec/main/distribution/discovery.json>
- Managed agent API: <https://vouchspec.plyrium.com/api/vouchspec/v1/health>
- Managed API discovery: <https://vouchspec.plyrium.com/api/vouchspec/v1/discovery>
- OpenAPI 3.1 contract: <https://vouchspec.plyrium.com/openapi.json>
- LLM-readable contract index: <https://vouchspec.plyrium.com/llms.txt>
- Installable Agent Skill index: <https://vouchspec.plyrium.com/.well-known/skills/index.json>
- Verify-before-install Agent Skill:
  <https://vouchspec.plyrium.com/.well-known/skills/vouchspec-verify-before-install/SKILL.md>
- Agentic Resource Discovery catalog (draft/proposal):
  <https://vouchspec.plyrium.com/.well-known/ai-catalog.json>
- A2A Agent Card: <https://vouchspec.plyrium.com/.well-known/agent-card.json>
- A2A JSON-RPC discovery: <https://vouchspec.plyrium.com/api/vouchspec/v1/a2a>
- Remote agent discovery (MCP): <https://vouchspec.plyrium.com/api/vouchspec/v1/mcp>
- Official MCP Registry API: <https://registry.modelcontextprotocol.io/v0.1/servers?search=io.github.mordiaky%2Fvouchspec>
- Agent Tools x402 listing:
  <https://agent-tools.cloud/api/v1/services/vouchspec-plyrium-com-sub91>
- Agent Tools MCP listing:
  <https://agent-tools.cloud/api/v1/mcp/servers/vouchspec-agent-skill-evidence>
- Agent Tools A2A listing:
  <https://agent-tools.cloud/api/v1/a2a/agents/vouchspec-agent-skill-evidence>
- Agent quickstart: <https://vouchspec.plyrium.com/vouchspec>
- Signed index over managed TLS: <https://raw.githubusercontent.com/mordiaky/vouchspec/main/catalog/public/index.dsse.json>
- Root-signed lifecycle feed: <https://raw.githubusercontent.com/mordiaky/vouchspec/main/catalog/public/lifecycle.dsse.json>
- Out-of-band root/issuer key publication: <https://gist.github.com/mordiaky/794e30c1c33ba1663921718cc8d530e1>

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.

## Product stages

- **Stage A — public artifact index (live):** selected public artifacts only; signed
  receipts and read-only REST/MCP retrieval; no uploads, private repositories, or
  customer-confidential content.
- **Stage B — public repository validation (live mainnet plus public testnet sandbox):** allowlisted public
  host, full commit, explicit subdirectory, bounded immutable retrieval, isolated no-egress
  worker, separate no-egress signing, durable tenant/order/payment state, an authenticated
  managed API, and exact x402 settlement. Commercial orders are live at 0.25 USDC on Base;
  the separate 1.00 test-USDC Base Sepolia sandbox remains available for integration testing.
- **Stage C — private/arbitrary inputs (deferred):** private storage, authentication,
  tenant isolation, deletion policy, and expanded legal/incident controls only after
  demand and revenue justify them.

Stage C is not a prerequisite for Stage A or B. No arbitrary upload route exists in the
Stage A server or MCP tools.

## Publisher CI — complete self-service example

The public [publisher-CI demo](https://github.com/mordiaky/vouchspec-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](https://github.com/mordiaky/vouchspec-demo/actions/runs/29331787790)
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:

```yaml
- id: vouchspec
  uses: mordiaky/vouchspec/distribution/github-action@ed812a14cbc62333d59bac319f79d897f14d1b64
  with:
    skill-path: path/to/skill
```

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](distribution/github-action/README.md).

## Evidence labels

Receipts use explicit labels, never a generic `VERIFIED` badge:

- `DIGEST_PINNED`
- `STRUCTURE_VALIDATED` (only when the structural profile passes)
- `STATIC_INSPECTION_COMPLETED`
- `INDEPENDENT_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.

## Verify a public receipt independently

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.

```powershell
vouchspec verify catalog\public\receipts\RECEIPT_ID.dsse.json `
  --key catalog\public\keys\issuer.jwk.json `
  --lifecycle catalog\public\lifecycle.dsse.json `
  --root-key catalog\public\keys\root.jwk.json
```

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.

## Read-only catalog API

```powershell
vouchspec serve-catalog --catalog-root catalog\public --port 8788 `
  --trusted-root-key C:\independently-provisioned\root.jwk.json
```

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/issuer`

All `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:

```powershell
vouchspec quote-fresh-validation docs\examples\fresh-validation-request.json
```

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`.

## Agent-only x402 mainnet

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.

## Agent-only x402 sandbox

The public service at `https://vouchspec-sandbox.plyrium.com` has no card form, hosted checkout,
or human approval step. An agent:

1. accepts terms version `vouchspec-stage-b-2026-07-14` at
   `POST /api/vouchspec/v1/tenants` and stores the one-time tenant bearer key;
2. sends the strict fresh-validation request to `POST /api/vouchspec/v1/quotes` with
   `Authorization` and a unique `Idempotency-Key`;
3. creates an order at `POST /api/vouchspec/v1/orders` and stores the returned delivery token;
4. calls the order's `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`;
5. polls the authenticated order, retrieves the exact DSSE result, and verifies it with the
   public issuer JWK.

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](https://github.com/mordiaky/vouchspec/blob/HEAD/distribution/discovery.json) 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](https://github.com/mordiaky/vouchspec/blob/HEAD/docs/stage-b-operations.md),
[payment flow](https://github.com/mordiaky/vouchspec/blob/HEAD/docs/payment-flow.md), [managed deployment boundary](https://github.com/mordiaky/vouchspec/blob/HEAD/deploy/README.md), and
[refund policy](https://github.com/mordiaky/vouchspec/blob/HEAD/docs/refund-policy.md), and
[mainnet remedy operations](https://github.com/mordiaky/vouchspec/blob/HEAD/docs/mainnet-remedy-operations.md).

## Local commerce harness

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:

```powershell
$env:VOUCHSPEC_AUTH_PEPPER_HEX = '<64 hex characters>'
$env:VOUCHSPEC_DELIVERY_SECRET_HEX = '<different 64 hex characters>'
vouchspec provision-commerce-tenant --database C:\vouchspec\sandbox-commerce.db
vouchspec serve-commerce-sandbox --database C:\vouchspec\sandbox-commerce.db --port 8789
```

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:

```powershell
vouchspec serve-commerce-stripe-test `
  --database C:\vouchspec\stripe-test-commerce.db --port 8789
```

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](https://github.com/mordiaky/vouchspec/blob/HEAD/deploy/README.md).

## Read-only catalog MCP

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:

```powershell
npx skills add mordiaky/vouchspec --skill vouchspec-verify-before-install
```

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:

```powershell
git clone https://github.com/mordiaky/vouchspec.git
cd vouchspec
python -m venv .venv
.venv\Scripts\python -m pip install .
.venv\Scripts\vouchspec mcp-catalog --catalog-root catalog\public `
  --trusted-root-key C:\independently-provisioned\root.jwk.json
```

```powershell
vouchspec mcp-catalog --catalog-root catalog\public `
  --trusted-root-key C:\independently-provisioned\root.jwk.json
```

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.

## Local inspector and builder

Development install:

```powershell
python -m venv .venv
.venv\Scripts\python -m pip install -e ".[dev]"
```

The compatibility command and Python package name `capabilityproof` remain available
alongside the public `vouchspec` command.

```powershell
vouchspec inspect C:\path\to\skill --output receipt.json
vouchspec inspect-git C:\checkout\skills\example `
  --repository-root C:\checkout --output receipt.json
```

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](https://github.com/mordiaky/vouchspec/blob/HEAD/docs/methodology.md), the
[receipt schema](https://github.com/mordiaky/vouchspec/blob/HEAD/src/capabilityproof/schemas/capability-receipt.schema.json), and the
[threat model](https://github.com/mordiaky/vouchspec/blob/HEAD/research/mvp-threat-model.md).

