BY HOOP.DEV / OPEN SOURCE

Every request,
inspected before it lands.

MCP Proxy sits between your AI agents and the tools they call, reviewing every request in real time and connecting safely to any MCP server you run.

Go nativeEmbeddableAuth built-in

How it works

01

Install the binary

One Go command installs mcpproxyd, no separate download step.

go install .../cmd/mcpproxyd@latest
02

Run it with a config

Point it at a YAML file describing your backends and policy.

mcpproxyd -config config.yaml
03

Connect your MCP client

Point Claude Code, Cursor, or any MCP client at the local endpoint.

http://127.0.0.1:8000/mcp

The check chain, in order

POST /mcp
tools/call · db_delete_all
{
  "method": "tools/call",
  "params": { "name": "db_delete_all" }
}
{
  "error": {
    "code": -32010,
    "message": "policy denied"
  }
}
session alive · mcp.tool_denied logged
checks.Assemblecanonical order · first non-allow verdict wins
01budgetPer-tool rate limits; truncates oversized results on the way back.
02policyAllow/deny globs. Strips denied tools from tools/list before the model sees them.
03approvalHolds a call for a human reviewer. Fails closed if no store is wired.
04s2c-gateDenies sampling/createMessage and elicitation/create by default.
05rug-pullSHA-256 fingerprints every tool. A change on a known tool kills the session by default.
06overridesRewrites aliased tool names back to real ones before every check after it.
07guardrailsBlocks on tool arguments; kills the session on a poisoned catalog.
08redactMasks sensitive content in result text before it reaches the client.
09audit-tapAlways allow. Logs the post-mutation message, exactly what the client gets.

Why it’s safe to run

Blocks the request, not your team

A blocked action returns a clear error and work keeps moving.

Hides risky tools before they’re used

Restricted tools never show up, so there’s nothing risky to pick.

Fits the stack you already run

Guardrails, masking, audits, and identity plug into your setup.

Govern every connection, not just one gateway.

Hoop runs the same inspection model centrally: policy, masking, guardrails, identity, and audit across every MCP server, database, and shell your team uses.

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