@blackwood-state/mcp

@blackwood-state/mcp

Blackwood State tools for AI agents over MCP. The package gives 33 pay-per-call tools, paid in USDC on Base over x402:

• onchain data: token prices, wallet balances and portfolio value, ENS, gas fees, new token pools;
• ECB exchange rates;
• text utilities: summarize, translate, sentiment;
• and more.

The server holds no wallet by default: when a call needs payment, it hands the agent the command that pays it from the wallet the agent already has (AgentCash or the Coinbase Agentic Wallet), capped at the price of that call.

claude mcp add blackwood -- npx -y @blackwood-state/mcp

Any MCP client over stdio:

{ "mcpServers": { "blackwood": { "command": "npx", "args": ["-y", "@blackwood-state/mcp"] } } }

How payment works

• Free demo credit. On first use, the server asks for US$0.05 of credit (one per IP per day) and keeps the key in ~/.blackwood/state.json. Set BLACKWOOD_NO_TRIAL=1 to skip it.
• Then the wallet you already have. Without credit, a paid tool returns its live price and two ready commands, and nothing is charged:
  • AgentCash: npx -y agentcash@0.17.1 fetch '<url>' -m POST -b '<json>' --max-amount <usd>
  • Coinbase Agentic Wallet, after npx awal auth login: npx -y awal@2.12.2 x402 pay '<url>' -X POST -d '<json>' --max-amount <atomic> The agent should ask the user before paying, unless the user already approved a budget.
• Other ways:
  • Prepaid credit: BLACKWOOD_CREDITS_KEY, a key bought at /v1/credits/5.
  • Advanced mode: BLACKWOOD_PRIVATE_KEY, a Base wallet that this server signs x402 payments with, only for Base USDC and only within the caps. Use a dedicated wallet that holds only what you plan to spend.
• Never charged for failures. A call that fails or rejects the input costs nothing.

Variable	Default
BLACKWOOD_CREDITS_KEY	none	prepaid credit key (bwk_...)
BLACKWOOD_PRIVATE_KEY	none	advanced mode: Base wallet that pays per call over x402
BLACKWOOD_MAX_USD_PER_CALL	0.05	cap per call in advanced mode
BLACKWOOD_MAX_USD_PER_DAY	1	cap per UTC day in advanced mode
BLACKWOOD_NO_TRIAL	unset	1 skips the free demo credit
BLACKWOOD_HOME	~/.blackwood	state directory

blackwood_account (free) shows the credit left, the paying wallet (advanced mode), today's spend and the caps.

The same routes are plain HTTP endpoints. Each one answers 402 with its price; see the OpenAPI at https://x402-gateway.blackwoodstate8.workers.dev/openapi.json. A skill for Agent Skills clients ships in skills/blackwood-state/SKILL.md.

Source: https://github.com/Blackwood-State/mcp. MIT license.