Synergy MCP

A pay-per-call MCP server exposing the Synergy specialist catalogue to MCP clients. Every specialist is an MCP tool; a tool call returns a structured x402 payment challenge (HTTP 402) that the calling agent settles in USDC from its own wallet before completing the call directly against the resource.

• Hosted endpoint (streamable HTTP): https://api.exo-trust.com/mcp

• Catalogue + prices: GET https://api.exo-trust.com/discovery

• Protocol: x402 · payments on Base (USDC, eip155:8453)

Why

MCP hosts the users; x402 hosts the rail. This server bridges the two: agents that speak MCP can discover and pay for specialist work per call without subscriptions, accounts, or API keys — the payment is the authorization.

The server deliberately holds no payment keys. It never pays, never settles, and never touches money: it returns the payment challenge so the calling agent settles with its own wallet and facilitator.

Related MCP server: DIEM Agent Workers

Tools

The tool registry is built live from /discovery (cached 300s), so new specialists appear without a server restart. As of v0.1.0 the catalogue includes:

All tools accept strict JSON input and return JSON only. Task payloads are treated as untrusted data; deterministic tools (sanctions/VAT/LEI/EDGAR/clinical) never run payloads through a shell, filesystem, or web tool.

Using the hosted endpoint

Point any MCP client at https://api.exo-trust.com/mcp with the streamable HTTP transport, then call a tool with a valid input payload. The response is a 402 Payment Required challenge:

{
  "status": 402,
  "message": "Payment required",
  "payment": {
    "amount": "50000",
    "network": "eip155:8453",
    "asset": "USDC",
    "payTo": "0xC9e2A96d0C9D5B1e0656862dFEf849C95B8aFA4C"
  }
}

Settle the challenge with your x402 wallet/facilitator, then POST the same payload to https://api.exo-trust.com/execute/<task_type> with the payment header to receive the result. See the x402 spec for the exact settlement flow.

Self-hosting

The server is a single Python file (mcp_server.py) with no state and no keys:

python3 -m venv .venv
.venv/bin/pip install -r requirements.txt

.venv/bin/python mcp_server.py            # stdio transport
.venv/bin/python mcp_server.py --http     # streamable HTTP on :8123
SYNERGY_BASE_URL=https://api.exo-trust.com .venv/bin/python mcp_server.py --http

• SYNERGY_BASE_URL — gateway base URL (default https://api.exo-trust.com).

• SYNERGY_MCP_PORT — HTTP port (default 8123).

• SYNERGY_MCP_CATALOG_TTL — catalogue cache TTL in seconds (default 300).

When proxying the HTTP transport behind a public hostname, the SDK's DNS-rebinding protection must be disabled for the public Host header (see main() in mcp_server.py).

License

MIT