@baselab-me/signals-mcp

MCP server for posting signal coins on Base chain via the signals platform.

Exposes three tools that let AI agents (Claude Desktop, Claude Code, etc.) create signal coins fully headlessly. Payment is via the x402 protocol — no platform account needed.

For non-MCP agents (OpenAI agents, BNKR, Base agents, custom scripts): Use the REST API directly. Skill document: https://signals.baselab.me/agent-skill.md

Tools

Modes

The MCP server works in two modes depending on which env vars are set:

Headless mode (keys set — fully automatic)

{
  "mcpServers": {
    "signals": {
      "command": "npx",
      "args": ["@baselab-me/signals-mcp"],
      "env": {
        "AGENT_PAYMENT_KEY": "0x...",
        "AGENT_TX_KEY": "0x...",
        "SIGNALS_API_URL": "https://signals.baselab.me"
      }
    }
  }
}

• AGENT_PAYMENT_KEY — wallet that pays x402 USDC fees (~$0.05/signal, ~$0.03/upload). Needs USDC on Base.

• AGENT_TX_KEY — wallet that signs and submits the on-chain coin creation TX. Needs ETH on Base.

• Both can be the same key. SIGNALS_API_URL defaults to https://signals.baselab.me.

Claude calls the tools, everything happens automatically, gets back txHash.

Keyless mode (no keys — returns unsigned payloads)

{
  "mcpServers": {
    "signals": {
      "command": "npx",
      "args": ["@baselab-me/signals-mcp"],
      "env": {
        "SIGNALS_API_URL": "https://signals.baselab.me"
      }
    }
  }
}

No env keys needed. Tools return structured unsigned payloads instead of auto-signing:

• create_signal_coin → { requiresPayment: true, eip3009: {...}, authorization: {...}, instructions: "..." } Claude signs the typed data with your wallet tool, then calls the tool again with paymentSignature + paymentAuthorization.

• submit_transaction → { requiresSigning: true, unsignedTx: { to, data, value, chainId: 8453 }, instructions: "..." } Claude submits via your wallet tool or you paste it into MetaMask.

Use this mode if you have a separate wallet MCP or want your own wallet to be the coin creator.

Security

AGENT_PAYMENT_KEY only needs USDC — fund it with a small amount (~$5-10). AGENT_TX_KEY only needs ETH for gas.

Use different keys for payment and TX signing to limit exposure:

• Payment key compromised → attacker can make ~100-200 free API calls at $0.05 each. No ETH risk.

• TX key compromised → only ETH for gas is at risk (no USDC needed).

Or omit both keys and use keyless mode — no key ever touches the MCP process.

The MCP server code is open source. Verify it before use.

Restart Claude Desktop

After editing the config file, restart Claude Desktop. The signals tools appear in Claude's tool palette.

Example usage

Tell Claude:

Post a signal coin with ticker HELLO, content "Hello from an agent!", from wallet 0xYourAddress.

Headless mode: Claude calls create_signal_coin (pays automatically) → calls submit_transaction (submits automatically) → returns txHash.

Keyless mode: Claude calls create_signal_coin → you sign the payment typed data → Claude calls again with signature → returns calldata → Claude calls submit_transaction → you submit via your wallet.

How signals are saved

When create_signal_coin succeeds, the server writes a pending record to the database with the signal's metadata URI as a match key. After submit_transaction lands the TX on-chain, a server-side cron job confirms the record by matching metadataUri from the TX logs.

This means signals created via the MCP are tracked in the signals platform — they appear in the creator's profile, on the leaderboard, and in the feed.

Signals created via the MCP are tagged with source: 'mcp' in the database.

REST API endpoints

The MCP server calls these endpoints on the signals API:

Both endpoints use the x402 payment protocol. First request without X-Payment header returns 402 with payment requirements. Second request with signed payment header returns the result.

Pairing tokens

Signal coins can be paired with different liquidity tokens:

Pass pairing: { kind: "base-coin", coinAddress: "0x..." } to create_signal_coin.

Development

# Build
pnpm build

# Run locally
node dist/index.js

# TypeScript check
pnpm exec tsc --noEmit

The MCP server requires Node.js >= 20.

License

MIT