`@ckb-ccc/nip07` lets any [NIP-07](https://github.com/nostr-protocol/nips/blob/master/07.md) compatible Nostr browser extension act as a CCC `Signer`. It derives a CKB address from the user's Nostr public key and signs CKB transactions via Nostr event signing.

<Callout type="info">
  If you're using `@ckb-ccc/connector-react` or `@ckb-ccc/ccc`, NIP-07 support is already included — no separate installation needed.
</Callout>

## Installation [#installation]

<PackageBadges pkg="@ckb-ccc/nip07" />

<Tabs items="['npm', 'yarn', 'pnpm']">
  <Tab value="npm">
    ```bash
    npm install @ckb-ccc/nip07
    ```
  </Tab>

  <Tab value="yarn">
    ```bash
    yarn add @ckb-ccc/nip07
    ```
  </Tab>

  <Tab value="pnpm">
    ```bash
    pnpm add @ckb-ccc/nip07
    ```
  </Tab>
</Tabs>

**Dependencies:**

| Package         | Description                                              |
| --------------- | -------------------------------------------------------- |
| `@ckb-ccc/core` | Base types — `Signer`, `Client`, `Transaction`, and more |

## Architecture [#architecture]

`@ckb-ccc/nip07` is a thin wrapper around the `window.nostr` object injected by NIP-07 extensions (e.g. nos2x, Alby).

<Mermaid
  chart="graph TB
    subgraph &#x22;NIP-07 Package&#x22;
        GS[&#x22;getNip07Signer(client)&#x22;]
        S[&#x22;Signer (extends SignerNostr)&#x22;]
    end

    subgraph &#x22;Provider&#x22;
        WN[&#x22;window.nostr&#x22;]
    end

    subgraph &#x22;Core&#x22;
        CorePkg[&#x22;@ckb-ccc/core (SignerNostr)&#x22;]
    end

    GS -->|&#x22;detects&#x22;| WN
    GS -->|&#x22;creates&#x22;| S
    S --> CorePkg
    S -->|&#x22;calls&#x22;| WN"
/>

### Entry point: `getNip07Signer` [#entry-point-getnip07signer]

`getNip07Signer(client)` checks for `window.nostr` and returns a `Signer` instance — or `undefined` if no NIP-07 extension is available:

<Mermaid
  chart="graph TD
    Start[&#x22;getNip07Signer(client)&#x22;] --> Check[&#x22;window.nostr exists?&#x22;]
    Check -->|No| Undef[&#x22;return undefined&#x22;]
    Check -->|Yes| Create[&#x22;new Signer(client, window.nostr)&#x22;]
    Create --> Return[&#x22;return Signer&#x22;]"
/>

## The `Signer` class [#the-signer-class]

`Signer` extends `ccc.SignerNostr` and wraps a NIP-07 provider with public key caching.

### Key methods [#key-methods]

| Method                  | Description                                                                  |
| ----------------------- | ---------------------------------------------------------------------------- |
| `connect()`             | Retrieves and caches the Nostr public key                                    |
| `isConnected()`         | Always returns `true` (NIP-07 extensions are always available once detected) |
| `getNostrPublicKey()`   | Returns the cached Nostr public key (hex-encoded)                            |
| `signNostrEvent(event)` | Signs a Nostr event via `provider.signEvent()`                               |

### Public key caching [#public-key-caching]

The Nostr public key is fetched once via `provider.getPublicKey()` and cached as a `Promise`. If the call fails, the cache is cleared so the next attempt retries:

```typescript
async getNostrPublicKey(): Promise<ccc.Hex> {
  if (!this.publicKeyCache) {
    this.publicKeyCache = this.provider.getPublicKey().catch((e) => {
      this.publicKeyCache = undefined;
      throw e;
    });
  }
  return ccc.hexFrom(await this.publicKeyCache);
}
```

### Signing flow [#signing-flow]

CKB transactions are signed by constructing a Nostr event and delegating to the extension:

<Mermaid
  chart="sequenceDiagram
    participant App as Application
    participant Signer as NIP-07 Signer
    participant Ext as Nostr Extension

    App->>Signer: sendTransaction(tx)
    Signer->>Signer: prepareTransaction(tx)
    Note over Signer: Add CellDeps, prepare witnesses
    Signer->>Ext: signEvent(nostrEvent)
    Ext->>Signer: signedEvent (with sig)
    Signer->>Signer: Pack signature into witness
    Signer->>App: txHash"
/>

## Provider interface [#provider-interface]

The NIP-07 provider interface is minimal:

| Method             | Returns               | Description                                             |
| ------------------ | --------------------- | ------------------------------------------------------- |
| `getPublicKey()`   | `Promise<string>`     | Returns the user's Nostr public key (hex)               |
| `signEvent(event)` | `Promise<NostrEvent>` | Signs a Nostr event and returns it with the `sig` field |

## Integration pattern [#integration-pattern]

`@ckb-ccc/nip07` follows the same integration contract as other wallet packages in CCC:

* **Factory function** — `getNip07Signer` returns a `Signer` or `undefined`.
* **Provider detection** — checks for `window.nostr` before creating the signer.
* **Graceful degradation** — returns `undefined` when no NIP-07 extension is installed.

This package is also used as a dependency by `@ckb-ccc/okx` for its Nostr signing support.


---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ckbccc.com/llms.txt
> Use this file to discover all available pages before exploring further.