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

# Farcaster

> Social protocol integration with Farcaster

<Warning>
  **Looking for Contributors!** This Skill needs an implementation.

  Contributing a Skill involves:

  1. Writing a reference implementation with full functionality
  2. Adding comprehensive tests
  3. Writing documentation with usage examples

  See the [ethers-provider Skill](https://github.com/evmts/voltaire/tree/main/examples/ethers-provider) for an example of a complete Skill implementation.

  Interested? Open an issue or PR at [github.com/evmts/voltaire](https://github.com/evmts/voltaire).
</Warning>

<Info>
  **Skill** — Copyable reference implementation. Use as-is or customize. See [Skills Philosophy](/concepts/skills).
</Info>

Integrate with Farcaster's on-chain identity and social graph.

## Planned Implementation

### Identity (ID Registry)

```typescript theme={null}
import { Farcaster } from './Farcaster.js';

const fc = Farcaster({
  provider,
  idRegistry: ID_REGISTRY,
  keyRegistry: KEY_REGISTRY,
});

// Get FID for address
const fid = await fc.getFid(address);

// Get custody address for FID
const custody = await fc.getCustodyAddress(fid);

// Register new FID
await fc.register({
  recovery: recoveryAddress,
  signer,
});
```

### Keys

```typescript theme={null}
// Add signer key
await fc.addKey({
  fid,
  key: signerPublicKey,
  keyType: 1, // Ed25519
  signer,
});

// Remove key
await fc.removeKey({
  fid,
  key: signerPublicKey,
  signer,
});
```

### Frames

```typescript theme={null}
// Validate frame action message
const { isValid, message } = await fc.validateFrameAction(
  trustedData.messageBytes
);

if (isValid) {
  console.log('FID:', message.fid);
  console.log('Button:', message.buttonIndex);
  console.log('Input:', message.inputText);
}
```

## Resources

* [Farcaster Documentation](https://docs.farcaster.xyz/)
* [Farcaster Contracts](https://github.com/farcasterxyz/contracts)
* [Frames Specification](https://docs.farcaster.xyz/reference/frames/spec)

## Related

* [siwe-authentication](/skills/siwe-authentication) — Sign-in patterns