# zcash-mcp

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ZAP1 receipts for Zcash agents: verify workflows without trusting the server.

ZAP1 is an attestation and proof rail for Zcash workflows. Frontier Compute
maintains the reference ZAP1 implementation.

A wrapper makes you trust the server. ZAP1 makes the server unnecessary to
trust.

Core rule: observe state, bound the claim, hash evidence, issue a receipt,
verify later.

MCP is the standard way for AI agents to call external tools. `zcash-mcp`
exposes the ZAP1 attestation layer for agents that need verifiable receipts
around Zcash workflows: create ZAP1 attestation leaves, query anchor state,
and verify proof receipts.

This is not a full wallet MCP. Balance scanning, private key custody, seed
handling, PCZT signing, shielded spend construction, and lightwalletd or Zaino
wallet synchronization are complementary wallet-layer work, not this server's
scope.

## Why ZAP1

Wallet MCPs can move value. ZAP1 proves the workflow around the value, and the
counterparty can verify the proof without trusting Frontier.

Tool servers expose what a backend says right now. ZAP1 produces a receipt that
another party can verify later from the schema, proof material, and Zcash anchor.

ZAP1 is the proof rail for Zcash agent workflows:

1. `attest`: create a typed event leaf.
2. `anchor`: commit leaves into a Merkle root anchored to Zcash.
3. `prove`: return a receipt packet for a leaf.
4. `verify`: let another party check the receipt without trusting the original
   agent.

Agent systems need more than a payment or a transaction lookup. They need a
receipt that another agent, user, auditor, or service can verify later:

- what event was asserted
- which agent or workflow asserted it
- which ZAP1 leaf records it
- which Merkle root includes it
- which Zcash transaction anchored that root
- how to verify the proof without trusting the original agent

That is the lane for this server. It gives Zcash agents a receipt layer that can
sit beside any wallet, signer, custody system, lightwalletd stack, Zaino stack,
or application-specific payment flow.

See [ZAP1 Proof Rail](docs/zap1-proof-rail.md) for the category boundary,
receipt model, integration pattern, and red-team rejects. See
[ZAP1 Conformance](docs/zap1-conformance.md) for the receipt contract agents
and integrations should satisfy. See
[Wallet Receipt Integration](docs/wallet-receipt-integration.md) for the
wallet-action handoff pattern. See
[External Rail Receipts](docs/external-rail-receipts.md) for generic
external-action receipt requests, and
[Receipt Disclosure Profiles](docs/receipt-disclosure-profiles.md) for
public, counterparty, auditor, grant, compliance, and internal packet shapes.

## Capability Boundary

The `zcash_capability_manifest` tool gives agents a machine-readable scope map:

- covered here: ZAP1 receipts, lifecycle attestations, proof verification, anchor
  state, memo decoding, and public chain context
- excluded here: custody, seed handling, balance scanning, PCZT signing,
  shielded spend construction, and wallet-server synchronization
- composition rule: use this server before or after wallet-layer actions to
  create, query, and verify receipts

Good fits:

- agent action receipts
- payment and invoice proof packets
- wallet action receipts
- external action receipts
- operator lifecycle events
- grant proof packets
- compliance audit packets
- policy and reputation attestations
- public anchor verification for private workflows
- cross-agent handoffs where the receiver needs proof, not custody

Poor fits:

- holding keys
- scanning wallet balances
- signing PCZTs
- broadcasting shielded spends
- replacing a wallet SDK

## Customer Flow

Use `zcash_receipt_template` first when you are wiring ZAP1 into a product. It
returns a customer-ready workflow for the receipt type you want:

- `agent_action`: prove an agent performed a named action with specific input
  and output hashes
- `payment_receipt`: bind invoice or payment metadata to a ZAP1 leaf and later
  prove inclusion under an anchored root
- `operator_lifecycle`: record deployment, upgrade, incident, recovery, or
  policy state as a verifiable lifecycle event
- `policy_attestation`: record an agent, service, or workflow policy decision
  as a verifiable event

Expected flow:

1. Call `zcash_capability_manifest` to confirm the attestation boundary.
2. Call `zcash_receipt_template` for the use case.
3. For wallet actions, call `zap1_wallet_receipt_request` to convert the wallet
   result into hash-only `attest_event` arguments.
4. Call `attest_event` to create the typed ZAP1 leaf.
5. Call `get_anchor_status` to check whether the leaf is anchored or waiting.
6. Call `verify_proof` to verify tree inclusion.
7. Call `zap1_prove_receipt` to fetch a handoff proof bundle.

Acceptance checks:

- the receipt has a leaf hash
- the leaf verifies under a returned Merkle root
- anchored receipts include an anchor transaction or anchor height
- another verifier can repeat verification without trusting the original agent
- no private keys, seeds, PCZTs, or wallet scan state were sent to this server

Red-team rejects:

- treating a payment URI as proof of payment
- treating an unanchored leaf as final settlement evidence
- treating a quote, route, or intent hash as settlement evidence by itself
- asking this server to sign, scan balances, recover seeds, or hold keys
- mixing custody claims into ZAP1 receipt claims
- hiding the distinction between wallet action and receipt verification

ZAP1 verifies ZAP1 receipts. It does not audit or guarantee any external wallet,
route, payment, bridge, exchange, or settlement system referenced by a receipt.

## Tools

| Tool | What it does |
|------|-------------|
| `zcash_capability_manifest` | Machine-readable scope map for agent use: covered surfaces, excluded wallet functions, and composition rules |
| `zcash_conformance_check` | Validate a ZAP1 receipt packet against the frozen v1 receipt contract |
| `zcash_receipt_template` | Customer-ready receipt workflow for agent actions, payment receipts, operator lifecycle events, and policy attestations |
| `zap1_wallet_receipt_request` | Convert a wallet-layer action result into hash-only ZAP1 receipt request fields |
| `zap1_attest_external_action` | Build a ZAP1 receipt request for an action executed by an external rail without routing, signing, custody, or settlement |
| `zap1_verify_external_receipt` | Validate an external-action ZAP1 receipt packet without trusting or calling the external rail |
| `zap1_extract_proof_artifact` | Extract the portable proof artifact from a ZAP1 receipt |
| `zap1_check_anchor_freshness_at_height` | Check anchor confirmation depth from supplied Zcash heights |
| `zap1_verify_receipt_chain` | Validate a sequence of ZAP1 receipt packets and summarize anchor state |
| `zap1_compare_receipt_claims` | Compare two ZAP1 receipts for claim, evidence, event, and anchor divergence |
| `zap1_audit_event_log` | Replay a receipt sequence against a caller-supplied event-type policy |
| `attest_event` | Create a typed ZAP1 attestation leaf for later anchoring |
| `verify_proof` | Verify a ZAP1 Merkle proof |
| `zap1_prove_receipt` | Fetch the full Merkle proof bundle for a leaf hash |
| `get_anchor_history` | All ZAP1 Merkle root anchors with txids and block heights |
| `get_anchor_status` | Current Merkle tree state: root, unanchored leaves, recommendation |
| `get_stats` | ZAP1 protocol stats: leaves, anchors, types |
| `get_events` | Recent ZAP1 attestation events with type, wallet hash, leaf hash |
| `get_agent_status` | Attestation summary for a ZAP1 agent ID |
| `zcash_identity_register` | Register an agent identity via AGENT_REGISTER attestation |
| `zcash_reputation_score` | Fetch agent bond data and policy compliance as a reputation object |
| `decode_memo` | Decode Zcash memo payloads: ZAP1 typed, ZIP 302, text, binary |
| `zap1_create_receipt_invoice` | Create ZAP1 receipt metadata for an external payment workflow |
| `zap1_watch_receipt_invoice` | Poll receipt-invoice status until paid or timeout |
| `get_block_height` | Current chain height from Zebra |
| `lookup_transaction` | Raw transaction data by txid |
| `zap1_verify_evm` | Verify a ZAP1 Merkle proof on-chain via EVM contract |

## Install

```bash
npx @frontiercompute/zcash-mcp
```

Or install globally:

```bash
npm install -g @frontiercompute/zcash-mcp
```

## Quickstart

Add this to your MCP config:

```json
{
  "mcpServers": {
    "zcash": {
      "command": "npx",
      "args": ["@frontiercompute/zcash-mcp"]
    }
  }
}
```

Restart your client and ask for the current Zcash block height. Read-only tools
do not need an API key.

Get a trial key for write operations:

```bash
curl -s -X POST https://api.frontiercompute.cash/trial-key
```

## Configuration

Environment variables:

| Variable | Default | Description |
|----------|---------|-------------|
| `ZEBRA_RPC_URL` | `http://127.0.0.1:8232` | Zebra node JSON-RPC endpoint |
| `ZAP1_API_URL` | `https://api.frontiercompute.cash` | ZAP1 attestation API |
| `ZAP1_API_KEY` | none | API key for write operations |

### Claude Desktop

Add to `~/Library/Application Support/Claude/claude_desktop_config.json`:

```json
{
  "mcpServers": {
    "zcash": {
      "command": "npx",
      "args": ["@frontiercompute/zcash-mcp"],
      "env": {
        "ZEBRA_RPC_URL": "http://127.0.0.1:8232",
        "ZAP1_API_KEY": "your-key-here"
      }
    }
  }
}
```

### Any MCP Client

The server communicates over stdio using JSON-RPC. Point your MCP client at the
`zcash-mcp` binary.

## Build From Source

```bash
git clone https://github.com/Frontier-Compute/zcash-mcp.git
cd zcash-mcp
npm ci
npm run build
node dist/index.js
```

## Testing

Offline verification covers the built stdio server and a clean-room install from
the packed npm tarball:

```bash
npm run test:offline
```

Live verification hits a real Zebra RPC and ZAP1 API:

```bash
ZEBRA_RPC_URL=http://127.0.0.1:8232 \
ZAP1_API_URL=http://127.0.0.1:3080 \
ZAP1_API_KEY=your-key-here \
npm run test:live
```

`test:live` drives the MCP server over stdio and exercises the live tool surface,
not just the underlying HTTP endpoints. Set `ZAP1_AGENT_ID` if you want the
`get_agent_status` check to target a specific deployed agent.

GitHub Actions mirrors that split:

- `.github/workflows/offline-ci.yml` runs deterministic packaging and MCP
  handshake checks on every push and pull request.
- `.github/workflows/live-e2e.yml` runs secret-backed live checks on `main`, on
  a schedule, and by manual dispatch.

## Dependencies

- A running [Zebra](https://github.com/ZcashFoundation/zebra) node for chain
  queries
- The ZAP1 API for attestation, proof, anchor, event, and receipt tools
- Memo decoding works locally with no external dependencies

## Related Packages

| Package | What it does |
|---------|-------------|
| [@frontiercompute/zcash-ika](https://www.npmjs.com/package/@frontiercompute/zcash-ika) | Zcash and Bitcoin signing via Ika 2PC-MPC |
| [@frontiercompute/openclaw-zap1](https://www.npmjs.com/package/@frontiercompute/openclaw-zap1) | OpenClaw skill for ZAP1 attestation |
| [@frontiercompute/zap1](https://www.npmjs.com/package/@frontiercompute/zap1) | ZAP1 attestation client |
| [@frontiercompute/silo-zap1](https://www.npmjs.com/package/@frontiercompute/silo-zap1) | Silo agent attestation via ZAP1 |

## Links

- [Dashboard](https://frontiercompute.cash/dashboard.html)
- [MCP Registry](https://registry.modelcontextprotocol.io/)
- [Frontier Compute](https://frontiercompute.cash)
- [Live stats](https://api.frontiercompute.cash/stats)

## License

MIT