@orquestradev/signer-mcp

MCP server for signing Solana transactions and messages using any backend supported by @solana/keychain.

One command to add to any MCP client:

{
  "mcpServers": {
    "solana-signer": {
      "command": "npx",
      "args": ["-y", "@orquestradev/signer-mcp"],
      "env": {
        "KEYCHAIN_BACKEND": "memory",
        "KEYCHAIN_PRIVATE_KEY": "<your-base58-private-key>",
        "SOLANA_RPC_URL": "https://api.mainnet-beta.solana.com"
      }
    }
  }
}

SOLANA_RPC_URL sets the default RPC endpoint used by sign_and_send_transaction. You can also override it per-call by passing rpcUrl in the tool arguments.

Tools

| Tool | Description | |---|---| | get_signer_address | Returns the signer's Solana public key | | check_signer_availability | Pings the backend to verify it is reachable | | sign_message | Signs an arbitrary message (UTF-8 or 0x-prefixed hex) | | sign_transaction | Signs a base64-encoded compiled transaction wire bytes | | sign_and_send_transaction | Signs and broadcasts a transaction; returns the tx signature (base58) |

Supported Backends

| KEYCHAIN_BACKEND | Required env vars | Optional package | |---|---|---| | memory | KEYCHAIN_PRIVATE_KEY | (bundled) | | privy | PRIVY_APP_ID, PRIVY_APP_SECRET, PRIVY_WALLET_ID | @solana/keychain-privy | | turnkey | TURNKEY_API_PUBLIC_KEY, TURNKEY_API_PRIVATE_KEY, TURNKEY_ORGANIZATION_ID, TURNKEY_SIGN_WITH | @solana/keychain-turnkey | | aws-kms | AWS_KMS_KEY_ID, AWS_REGION | @solana/keychain-aws-kms | | gcp-kms | GCP_PROJECT_ID, GCP_LOCATION_ID, GCP_KEY_RING_ID, GCP_CRYPTO_KEY_ID, GCP_CRYPTO_KEY_VERSION_ID | @solana/keychain-gcp-kms | | fireblocks | FIREBLOCKS_API_KEY, FIREBLOCKS_API_SECRET_PATH, FIREBLOCKS_VAULT_ACCOUNT_ID | @solana/keychain-fireblocks | | dfns | DFNS_APP_ID, DFNS_AUTH_TOKEN, DFNS_WALLET_ID, DFNS_CREDENTIAL_ID, DFNS_PRIVATE_KEY_PEM_PATH | @solana/keychain-dfns | | vault | VAULT_ADDR, VAULT_TOKEN, VAULT_KEY_NAME | @solana/keychain-vault | | cdp | CDP_API_KEY_NAME, CDP_API_KEY_PRIVATE_KEY, CDP_WALLET_ID, CDP_ADDRESS_ID | @solana/keychain-cdp | | crossmint | CROSSMINT_API_KEY, CROSSMINT_WALLET_LOCATOR | @solana/keychain-crossmint | | openfort | OPENFORT_SECRET_KEY, OPENFORT_ACCOUNT_ADDRESS | @solana/keychain-openfort | | para | PARA_API_KEY, PARA_WALLET_ID, PARA_USER_SHARE | @solana/keychain-para |

Non-memory backends require their optional package to be installed alongside this package:

npm install @orquestradev/signer-mcp @solana/keychain-privy

MCP Client Config Examples

Claude Desktop (~/Library/Application Support/Claude/claude_desktop_config.json)

{
  "mcpServers": {
    "solana-signer": {
      "command": "npx",
      "args": ["-y", "@orquestradev/signer-mcp"],
      "env": {
        "KEYCHAIN_BACKEND": "memory",
        "KEYCHAIN_PRIVATE_KEY": "<base58-or-path-to-keypair.json>"
      }
    }
  }
}

AWS KMS example

{
  "mcpServers": {
    "solana-signer": {
      "command": "npx",
      "args": ["-y", "@orquestradev/signer-mcp"],
      "env": {
        "KEYCHAIN_BACKEND": "aws-kms",
        "AWS_KMS_KEY_ID": "arn:aws:kms:us-east-1:...",
        "AWS_REGION": "us-east-1"
      }
    }
  }
}

Privy example

{
  "mcpServers": {
    "solana-signer": {
      "command": "npx",
      "args": ["-y", "@orquestradev/signer-mcp"],
      "env": {
        "KEYCHAIN_BACKEND": "privy",
        "PRIVY_APP_ID": "clxxxxxxxxxxxxxxxx",
        "PRIVY_APP_SECRET": "your-app-secret",
        "PRIVY_WALLET_ID": "your-wallet-id"
      }
    }
  }
}

Development

# Install dependencies
npm install

# Build
npm run build

# Run locally (memory backend)
KEYCHAIN_BACKEND=memory KEYCHAIN_PRIVATE_KEY=<base58-key> node dist/index.js

sign_and_send_transaction

Accepts transaction (base64 wire), optional rpcUrl, and optional skipPreflight. Uses SOLANA_RPC_URL env var if rpcUrl is not passed; falls back to mainnet.

{
  "transaction": "<base64-wire-bytes>",
  "rpcUrl": "https://api.devnet.solana.com",
  "skipPreflight": false
}

Security

• Private keys for the memory backend are held in-process as non-extractable CryptoKey objects via the Web Crypto API.
• Never commit private keys to source control. Use environment variables or a secret manager.
• For production workloads, prefer a remote signing backend (AWS KMS, GCP KMS, Turnkey, Privy, etc.).
• All tool inputs are validated before being passed to the signer.

License

MIT