pulse

MCP Gateway

One unified Model Context Protocol server that exposes all five Distill agents as native tools. Point any MCP client — Claude Desktop, Daydreams, or your own — at one endpoint and get every Distill agent as a callable tool.

Endpoint: POST https://mcp-gateway-production-e02e.up.railway.app/mcp Health: GET https://mcp-gateway-production-e02e.up.railway.app/ (free) Transports: stdio (local / Claude Desktop) · Streamable HTTP + SSE (remote) Network: Base Mainnet (eip155:8453) · USDC Source: Quitx5454/mcp-gateway

What it does

The gateway is a thin, stateless adapter: each Distill agent becomes one MCP tool. When a tool is called, the gateway forwards the request to the agent’s x402 endpoint and returns the result. It does not re-implement any agent logic — it’s pure routing + payment glue, so the tool catalog always matches the live agents.

The same single McpServer is served over two transports, so it works both as a local Claude Desktop server (stdio) and as a remote HTTP service.

The 6 tools

Tool	Agent	Method	Price	What it does
`refine`	Refine	POST	0.02 USDC	Clean raw transaction data, filter bots, return structured output
`forge`	Forge	POST	0.02 USDC	Compile an ERC-8004 reputation proof (keccak-256 hash + IPFS + giveFeedback calldata)
`trace`	Trace	POST	0.01 USDC	Normalize a raw execution log into structured steps + a `forge_ready` block
`shield`	Shield	POST	0.005 USDC	Strip PII from an x402 request + issue an HMAC-SHA256 replay guard
`pipeline_invoke`	Pipeline	POST	0.03 USDC	Chain any combination of the agents in one async call (returns a `task_id`)
`pipeline_status`	Pipeline	GET	free	Poll a pipeline run’s status and results by `task_id`

Each tool ships a strict, typed input schema mirroring the agent’s documented input, so MCP clients (and the models driving them) know exactly how to call it.

Connect from Claude Desktop (stdio)

Clone the repo, then add the gateway to your Claude Desktop config (claude_desktop_config.json):

{
  "mcpServers": {
    "distill": {
      "command": "bun",
      "args": ["run", "/absolute/path/to/mcp-gateway/src/index.ts", "--stdio"],
      "env": { "PRIVATE_KEY": "0x..." }
    }
  }
}

--stdio selects the stdio transport (you can also set MCP_TRANSPORT=stdio).
PRIVATE_KEY is optional — see Payment model. Without it, paid tools return the payment challenge for your client to settle.

Restart Claude Desktop; the six Distill tools appear under the distill server.

Connect remotely (HTTP / SSE)

The hosted gateway speaks the MCP Streamable HTTP transport (which supports SSE streaming) at POST /mcp, statelessly:

# initialize
curl -X POST https://mcp-gateway-production-e02e.up.railway.app/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":1,"method":"initialize",
       "params":{"protocolVersion":"2025-06-18","capabilities":{},
                 "clientInfo":{"name":"my-client","version":"0"}}}'

# list tools
curl -X POST https://mcp-gateway-production-e02e.up.railway.app/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/list"}'

Any MCP-compatible client library (e.g. the official SDK’s StreamableHTTPClientTransport, or Daydreams’ @x402/mcp) can connect to that URL directly. GET / returns a free health check.

Payment model

Five of the six tools are x402-protected. The gateway can pay automatically when configured with a wallet (PRIVATE_KEY), using the same EVM exact-scheme client (viem + @x402/evm) the Pipeline agent uses for its downstream payments.

A 402 is never swallowed. If a payment can’t be settled — no wallet configured, insufficient funds, or facilitator rejection — the gateway surfaces the x402 challenge as an MCP tool error whose structured content carries the decoded payment_required payload. A paying client framework (such as Daydreams @x402/mcp) can intercept that error and complete the payment itself.

The public hosted gateway runs in passthrough mode (no wallet): its /mcp endpoint is unauthenticated, so it never spends funds on anyone’s behalf — it hands the challenge back to the caller. Run your own instance with a PRIVATE_KEY if you want it to pay for you.

Environment

Variable	Required	Purpose
`PRIVATE_KEY`	for auto-pay	Gateway wallet that settles x402 challenges. Absent → passthrough (challenge returned to client).
`SEEDER_PRIVATE_KEY`	seed script only	Wallet used by `scripts/seed-bazaar.ts`.
`RPC_URL`	no	Base RPC (default `https://mainnet.base.org`).
`PORT`	no	HTTP port (default 3000).
`AGENT_TIMEOUT_MS`	no	Per-agent request timeout (default 60000).
`MCP_TRANSPORT`	no	Set to `stdio` to force the stdio transport.
`REFINE_URL` / `FORGE_URL` / `SHIELD_URL` / `PIPELINE_URL`	no	Override agent base URLs (default: production).

Seeding x402 Bazaar

scripts/seed-bazaar.ts calls each of the five invoke endpoints once with realistic data, paying with a seeder wallet. A settled payment through the CDP facilitator is what triggers indexing into the x402 Bazaar catalog. It prints the on-chain settlement tx hash for each agent.

SEEDER_PRIVATE_KEY=0x... bun run seed

Costs real USDC on Base Mainnet (~0.085 USDC total). Run once.

Pricing

tool	cost
`refine` · `forge`	0.02 USDC
`trace`	0.01 USDC
`shield`	0.005 USDC
`pipeline_invoke`	0.03 USDC
`pipeline_status`	free

The tool prices are exactly the underlying agents’ prices — the gateway adds no markup.

Source

GitHub: Quitx5454/mcp-gateway · part of the Distill suite.