# Shinjuku Shielded [Health: Active]

**Category:** 💰 Finance & Fintech  
**Repository:** https://github.com/ShinjukuStaition/shinjuku-mcp  
**GitHub Stars:** 2  
**Views:** 0  
**Installs:** 0  
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**Directory Page:** https://allmcps.com/mcp/shinjuku-shielded

## Description
Private x402 payments on Solana: shield, pay, and unshield USDC under caps you set.

## Tools
Capabilities this server exposes over MCP:

- **shinjuku_setup** — Asks you to confirm in your MCP client that it may create a Shinjuku Shielded wallet on this machine, and shows the caps. Then it runs the setup and switches the same server to the wallet tools. It never asks for a secret. A client that cannot ask is told to run `npx -y shinjuku-shielded setup` in…
- **wallet_status** — Says whether the wallet is set up, and what to do next.
- **wallet_shield** — Moves USDC from the wallet's own Solana key into your shielded balance. It is on with `--proof-tools`. `--no-shield` turns it off. Funding takes minutes: the first call starts it and returns a stage. Call again with the same `request_id` to see the stage. It never starts a second deposit. When the…
- **x402_discover** — Searches public x402 listings (Coinbase x402 Bazaar, PayAI, Dexter, and others) on your machine and returns the sellers that match. Pays nothing. The first call takes about 15 s.
- **x402_preview** — One unpaid request. Returns the seller's price, the scheme, and whether your caps allow it. Pays nothing. For a standard `exact` seller it adds `feeAtomic` (our fee) and `totalAtomic` (price plus fee, what leaves your balance). A seller that lists several networks is priced from its Solana offer.
- **x402_pay** — Pays the URL (if it asks for payment) and returns the answer. A URL that does not answer 402 is fetched once and nothing is paid. An image answer (image bytes, or JSON `image_base64`) comes back as an MCP image block, and the file is saved. A payment that landed, from a seller that gives no answer,…
- **wallet_unshield** — Sends shielded USDC to a public Solana address. It is on with `--exit-proof-tools` and `--profile`. Our facilitator pays every network fee. The same `request_id` never unshields twice. An address that you named with `--unshield-to` is sent at once. Any other address is sent only after you confirm i…
- **wallet_balance** — ONE balance (`balanceAtomic`, what `x402_pay` can spend) and UNSHIELDED (plain USDC on the wallet's own Solana key). `breakdown` names the parts of the one balance: `shieldedAtomic` (what `wallet_unshield` can send), `refundsInFlightAtomic` (a Shinjuku refund on its way back), and `setAsideAtomic`…
- **wallet_receipts** — Your most recent paid receipts: host (never the full URL), amount, transaction, time.

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

```json
"mcpServers": {
  "shinjuku-shielded": {
    "command": "npx",
    "args": ["-y","shinjuku-shielded"]
  }
}
```

## Documentation

## What Shinjuku Shielded does

Shinjuku Shielded MCP server gives an MCP client access to a local Solana wallet and a shielded USDC balance. The wallet remains on the user's machine, while the agent can request account status, move USDC into the shielded balance, pay supported x402 sellers, and send funds back to a public Solana address.

Payment tools cover public x402 discovery, unpaid previews, and URL fetching with payment when a seller returns a 402 response. The server supports shielded-exact offers and standard Solana exact offers routed through Shinjuku. It can also return image responses as MCP image blocks and save the image file.

## How it works

The server starts in setup mode when no wallet exists. `shinjuku_setup` asks the MCP client to confirm wallet creation and displays the configured caps. After setup, the same server switches to wallet tools. Clients that cannot present the confirmation can run `npx -y shinjuku-shielded setup` in a terminal.

Funds first sit as plain USDC on the wallet's Solana key. `wallet_shield` moves them into the shielded balance; the wallet key does not need SOL because the facilitator's relayer pays the network fee. A shield operation can take minutes, so the client should repeat the same `request_id` to check progress rather than start another deposit.

For payments, `x402_discover` searches public listings such as Coinbase x402 Bazaar, PayAI, and Dexter. `x402_preview` reports the seller price, scheme, and cap check without paying. `x402_pay` then fetches the URL and pays only when required. Reusing a `request_id` resumes the existing operation and prevents duplicate payment.

The Shinjuku Shielded MCP server records caps during setup. Calls may lower those limits but cannot raise them. `wallet_unshield` requires confirmation for destinations that were not configured in advance, and it refuses the wallet's own address to avoid linking deposits and exits.

## Setup and configuration

Run the MCP command with `npx -y shinjuku-shielded mcp` in an MCP client configuration. Setup creates the local wallet, a private passphrase file, and checked proof tools without asking the user to provide a secret. The server uses a relay for reads by default; a user-provided RPC takes precedence.

Optional command-line modes control wallet operations. `--tor` hides the user's IP from the payment service, `--proof-tools` enables shielding, and `--exit-proof-tools` with `--profile` enables unshielding. `--no-shield` disables shielding. The provided material does not specify required environment variables.

## Tools and capabilities

- `wallet_status` reports whether setup is complete and gives the next action.
- `wallet_balance` reports spendable and unshielded USDC, including shielded funds, refunds in flight, and older set-aside value.
- `wallet_receipts` lists recent paid hosts, amounts, transactions, and times without exposing full URLs.
- `wallet_cancel` closes an unfinished payment and returns its reserved balance.
- `wallet_unshield` sends shielded USDC to a public Solana address after the required confirmation.

If a payment succeeds but the seller does not return an answer, the payment remains recorded as paid. If a standard exact seller rejects the payment, the price and fee return automatically within about two minutes.

## Limitations and notes

The first discovery request takes about 15 seconds. A single payment can use one account and up to three notes; if no account covers the amount, the wallet must be merged with `shinjuku-wallet merge` before trying again. Standard exact payments require the configured maximum to cover both the seller price and Shinjuku's fee.

The server does not pay when a URL does not return a 402 response. Shielding and unshielding are asynchronous or confirmation-gated operations, and disabled wallet tools return an error explaining what must be enabled. Older confidential V0b vault amounts are no longer supported, although older pocketed value can be returned to the shielded balance by the wallet.

_Full upstream README: https://allmcps.com/mcp/shinjuku-shielded/readme_