---
title: Nostrbook Extension
description: Add Nostrbook MCP Server as a goose Extension
---

import Tabs from '@theme/Tabs';
import TabItem from '@theme/TabItem';
import GooseDesktopInstaller from '@site/src/components/GooseDesktopInstaller';
import CLIExtensionInstructions from '@site/src/components/CLIExtensionInstructions';


This tutorial covers how to add the [Nostrbook MCP Server](https://gitlab.com/soapbox-pub/nostrbook) as a goose extension to provide access to a comprehensive registry of Nostr documentation that helps users understand the decentralized social protocol, its implementation possibilities, and technical specifications.


:::tip Quick Install
<Tabs groupId="interface">
  <TabItem value="ui" label="goose Desktop" default>
    [Launch the installer](goose://extension?cmd=npx&arg=-y&arg=%40nostrbook%2Fmcp&id=nostrbook&name=Nostrbook&description=A%20comprehensive%20registry%20of%20Nostr%20documentation%20with%20structured%20knowledge)
  </TabItem>
  <TabItem value="cli" label="goose CLI">
    **Command**
    ```sh
    npx -y @nostrbook/mcp@latest
    ```
  </TabItem>
</Tabs>
:::

## Configuration

:::info
Note that you'll need [Node.js](https://nodejs.org/) installed on your system to run this command, as it uses `npx`.
:::


<Tabs groupId="interface">
  <TabItem value="ui" label="goose Desktop" default>
  <GooseDesktopInstaller
    extensionId="nostrbook"
    extensionName="Nostrbook"
    description="A comprehensive registry of Nostr documentation with structured knowledge"
    command="npx"
    args={["-y", "@nostrbook/mcp"]}
  />
  </TabItem>
  <TabItem value="cli" label="goose CLI">
    <CLIExtensionInstructions
      name="Nostrbook"
      description="A comprehensive registry of Nostr documentation with structured knowledge"
      command="npx -y @nostrbook/mcp@latest"
    />
  </TabItem>
</Tabs>

## Example Usage

### goose Prompt

> _goose, what is the NIP-61 and how can I implement it?._


### goose Output

Note that IDs have been changed to generic ones

:::note CLI

<details>
    <summary>Tool Calls</summary>

    ─── read_nip | nostrbook ──────────────────────────

    nip: 61

</details>



# NIP-61: Implementing Nutzaps

NIP-61 defines "Nutzaps," which are P2PK Cashu tokens where the payment itself acts as the receipt. This protocol allows for Bitcoin micropayments through the Nostr ecosystem using Cashu tokens.

## Core Concept

Nutzaps enable users to send small Bitcoin payments to each other through Nostr events, with the tokens being locked to the recipient's specified public key.

## Implementation Guide

### Prerequisites

1. Familiarize yourself with [Cashu](https://cashu.space/) and [P2PK token locking](https://github.com/cashubtc/nuts/blob/main/11.md)
2. Understand [NIP-60](https://github.com/nostr-protocol/nips/blob/master/60.md) for wallet functionality
3. Ensure your implementation supports NUT-11 (P2PK) and NUT-12 (DLEQ proofs)

### Step 1: Set Up Recipient Information (For Receiving Nutzaps)

Create and publish a `kind:10019` event to inform others how to send you money:

```json
{
    "kind": 10019,
    "tags": [
        ["relay", "wss://your-relay1.com"],
        ["relay", "wss://your-relay2.com"],
        ["mint", "https://your-trusted-mint.com", "sat"],
        ["pubkey", "<your-p2pk-pubkey>"]
    ]
}
```

- The `pubkey` should be a dedicated public key (NOT your Nostr identity key)
- Store the corresponding private key safely in your NIP-60 wallet event
- List only mints you trust and monitor

### Step 2: Building the Sender Functionality

To implement nutzapping:

1. **Query recipient information**:
   ```javascript
   // Fetch recipient's kind:10019 event
   const recipientInfo = await relay.get({
     kinds: [10019],
     authors: [recipientPubkey]
   });
   ```

2. **Extract mint and P2PK information**:
   ```javascript
   const recipientMints = recipientInfo.tags
     .filter(tag => tag[0] === 'mint')
     .map(tag => tag[1]);
   
   const recipientLockKey = recipientInfo.tags
     .find(tag => tag[0] === 'pubkey')?.[1];
   ```

3. **Mint or swap tokens** at one of the recipient's trusted mints, P2PK-locking them to their specified key

4. **Publish the nutzap event**:
   ```json
   {
       "kind": 9321,
       "content": "Thanks for your post!",
       "tags": [
           ["proof", "{\"amount\":1,\"C\":\"02...3f\",\"id\":\"000...\",\"secret\":\"[\\\"P2PK\\\",...]\"}"],
           ["u", "https://recipient-specified-mint.com"],
           ["e", "<event-being-zapped>", "<relay-hint>"],
           ["p", "<recipient-pubkey>"]
       ]
   }
   ```

### Step 3: Building the Recipient Functionality

To implement nutzap receiving:

1. **Query for incoming nutzaps**:
   ```javascript
   // Subscribe to nutzap events
   relay.subscribe([
     {
       kinds: [9321],
       "#p": [myPubkey],
       "#u": myTrustedMints,
       since: lastCheckTimestamp
     }
   ]);
   ```

2. **Validate incoming nutzaps**:
   - Verify the token is from a mint you've specified
   - Verify the token is locked to your P2PK key
   - Verify the DLEQ proof

3. **Redeem the token**:
   - Swap the P2PK token into your wallet
   - Create a `kind:7376` event to record redemption:
   ```json
   {
       "kind": 7376,
       "content": "<encrypted-content>", 
       "tags": [
           ["e", "<nutzap-event-id>", "", "redeemed"],
           ["p", "<sender-pubkey>"]
       ]
   }
   ```

### Important Implementation Details

1. **P2PK Key Prefixing**: Always prefix the P2PK-lock public key with "02" for compatibility
2. **Token Verification**: Implement local verification of DLEQ proofs
3. **Mint URL Normalization**: Normalize mint URLs to avoid issues with slight URL variations
4. **User Guidance**: Guide users to use only NUT-11 and NUT-12 compatible mints
5. **Publishing Locations**: Publish nutzap events to the recipient's specified relays

## Testing

When testing your implementation:
1. Create test nutzaps with small amounts
2. Verify token redemption works correctly
3. Check that redemption records are properly created
4. Test with multiple mints for compatibility

## Security Considerations

- Never use the user's main Nostr key for P2PK operations
- Ensure proper encryption of sensitive wallet data
- Validate all proofs before attempting to redeem tokens
- Only interact with explicitly trusted mints

By following these steps, you can implement a complete nutzap solution that allows users to send and receive Bitcoin micropayments through the Nostr protocol using Cashu tokens.

:::