Atlas / MCP servers / chris-schra / Funnel

FunnelBLOCK

Name: Funnel
Author: chris-schra

mcp/chris-schra/funnel

MCP server by chris-schra · Audited 2026-10-07

Finally, a proxy that does what grep does for logs - filters out the noise. Stop carrying 70k tokens of tools you'll never use. It's like tree-shaking, but for MCP. 🚀

Verdict

BLOCK

Grade

Trust score

66 /100

Exposed tools

57 50r · 7w · 0d

Transport

stdio · streamable-http

License

MIT

Stars

157

Overview

From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.

Core infrastructure package for MCP Funnel. Provides transport implementations, secret management, logging, authentication utilities, and resilient connection management.

Installation

yarn add @mcp-funnel/core

Features

Multiple Transport Implementations: stdio, SSE, HTTP, and WebSocket client transports for MCP communication
Secret Management: Secure secret provider system with dotenv, process env, and inline providers
Structured Logging: Pino-based logging with automatic credential redaction
Connection Resilience: Exponential backoff and automatic reconnection management
Authentication Utilities: Interfaces and types for implementing OAuth and bearer token auth
Environment Resolution: Secure variable interpolation with ${VAR} patterns and circular reference detection

Key Components

Transports

Client transport implementations for the Model Context Protocol:

StdioClientTransport: Communicates with child processes via stdin/stdout using newline-delimited JSON-RPC
SSEClientTransport: Server-Sent Events transport with OAuth authentication support
StreamableHttpClientTransport: HTTP-based streaming transport
WebSocketClientTransport: WebSocket-based bidirectional transport
BaseClientTransport: Abstract base class with shared transport functionality

All transports implement the MCP SDK Transport interface for seamless integration.

Secret Management

Secure secret provider system with fine-grained control:

SecretManager: Orchestrates multiple secret providers with precedence rules
Providers:
DotEnvProvider: Loads secrets from .env files
ProcessEnvProvider: Filters process environment variables by prefix
InlineProvider: Defines secrets directly in configuration
SecretProviderRegistry: Manages provider registration and discovery
Security Features:
Environment variable filtering to prevent credential lea

Read from source at commit d4b577033725OBSERVED · 2026-10-07

Connect

Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control. Replace the environment placeholders with a token scoped to the least it needs.

claude-code

claude mcp add web --env API_KEY=${API_KEY} --env AUTH_ENDPOINT=${AUTH_ENDPOINT} --env CLIENT_SECRET=${CLIENT_SECRET} --env DISABLE_INBOUND_AUTH=${DISABLE_INBOUND_AUTH} -- npx -y @mcp-funnel/[email protected]

claude-desktop

{
  "mcpServers": {
    "web": {
      "command": "npx",
      "args": [
        "-y",
        "@mcp-funnel/[email protected]"
      ],
      "env": {
        "API_KEY": "${API_KEY}",
        "AUTH_ENDPOINT": "${AUTH_ENDPOINT}",
        "CLIENT_SECRET": "${CLIENT_SECRET}",
        "DISABLE_INBOUND_AUTH": "${DISABLE_INBOUND_AUTH}"
      }
    }
  }
}

Exposed tools (57)

50 read · 7 write · 0 destructive.

Tool	Risk	Description
`big_tool`	read	Test
`bridge_tool_request`	write	Execute any discovered tool dynamically. First use get_tool_schema to understand the required arguments structure.
`create_issue`	write	Create a GitHub issue
`create_pr`	write	Create a PR
`create_pull_request`	write	Create a pull request
`debug_info`	read	Debug tool
`discover_tools_by_words`	read	Search for tools by keywords in their descriptions. Returns matching tools that can be dynamically enabled to reduce context usage.
`echo`	read	Echo back the message
`echo_tool`	read	Echoes input
`env-server`	read	Server with complex environment setup
`example`	read	Example tool for testing
`exposed_tool`	read	A tool that should be exposed
`filesystem-server`	read	MCP server for filesystem operations
`fs-001`	read	MCP server for filesystem operations
`getResults`	read	Query test results. Returns summary only by default. Specify testFile or testName (supports globs) to get detailed results showing all test statuses. Returns failed tests only when no filters specified.
`getSessionStatus`	write	Get current status of a test session including run state and summary statistics.
`get_teams`	read	Get teams
`get_tool_schema`	read	Get the input schema for a specific tool. Use the returned schema to understand what arguments are required for bridge_tool_request.
`github-mcp-server`	read	GitHub MCP Server
`hidden_tool`	read	A tool that should be hidden
`hybrid-server`	read	Server with both package and remote options
`js-debugger_debuggerCommand`	read	Control execution flow for an existing debugger session.
`js-debugger_getScopeVariables`	read	Inspect variables within a paused call frame scope.
`js-debugger_queryOutput`	read	Retrieve buffered stdout, stderr, console, and exception output.
`js-debugger_startDebugSession`	read	Spawn a Node.js target and attach a debugger session.
`large_tool`	read	Returns large data
`list_files`	read	List files in a directory
`list_issues`	read	List GitHub issues
`lookup`	read	Get detailed information about an NPM package
`mcp-funnel-server`	read	MCP proxy server
`multi-package-server`	read	Server with multiple package options
`normal_tool`	read	Matches exposeTools
`npm-server`	read	Server from NPM package
`oci-server`	read	Server from OCI container
`official-server`	read	Server from official registry
`other-server`	read	Other server
`other_tool`	read	Not in exposeTools
`private_tool`	read	A private tool that should be hidden
`public_tool`	read	A public tool that should be discoverable
`pypi-server`	read	Server from PyPI package
`queryConsole`	read	Search and filter console output from test session.
`read_file`	read	Read contents of a file
`remote-server`	read	Server accessed remotely
`search`	read	Search for NPM packages
`secret_tool`	read	A secret tool that should be hidden
`startSession`	write	Start a vitest test session. Returns sessionId and summary stats.
`super_tool`	read	Always visible
`test-cmd`	read	Test
`test-server`	read	Test server
`test__tool1`	read	[test] Tool 1
`test__tool2`	read	[test] Tool 2
`test_tool`	read	A test tool
`tool`	read	A simple tool
`tool1`	read	Tool 1
`tool2`	read	Tool 2
`unknown-server`	read	Server with unknown type
`write_file`	write	Write contents to a file

Trust audit

BLOCKgrade D · trust 66/100 Do not install this without reading the findings. The audit found something that could harm you or your machine.

Layer	What it checks	Result
L0	Provenance & inventory	WARN
L1	Static analysis of the code	WARN
L2	Instruction surface (what it tells the agent)	FAIL
L3	Class-specific surface	PASS
L4	Behavioural (sandbox)	SKIPPED

What the source does

Filesystem: declared (1 observation(s))
Network: declared (5 observation(s))
Shell: declared (5 observation(s))
Dependencies: not all pinned
Secrets in source: found

Findings (25)

HIGHPrompt injection · prompt.hidden_comment · CWE-94, CWE-1427

.haino/personas/coordinator.md:91

<!-- Fill in the the checklist above and check the ones you verified (you MUST verify all or give justification -->

Why it matters. directive hidden in a comment the user does not see rendered

Fix. remove the comment

MEDIUMInventory / provenance · inv.symlink · CWE-1104

packages/mcp/docs

packages/mcp/docs

Why it matters. link not followed

MEDIUMInformation disclosure · disclose.log_secret · CWE-209, CWE-532

packages/core/src/secrets/secret-manager.ts:53

* console.log(secrets.API_KEY); // Value from the last provider that resolved it

MEDIUMHard-coded secrets · secret.generic · CWE-798, CWE-321

packages/auth/src/provider/__tests__/memory-oauth-storage.test.ts:99

token: 'test-access-token-123',

MEDIUMHard-coded secrets · secret.generic · CWE-798, CWE-321

packages/auth/src/provider/__tests__/memory-oauth-storage.test.ts:131

token: 'test-refresh-token-123',

MEDIUMHard-coded secrets · secret.generic · CWE-798, CWE-321

packages/auth/src/provider/__tests__/memory-oauth-storage.test.ts:223

token: 'expired-refresh-token',

MEDIUMHard-coded secrets · secret.private_key · CWE-798, CWE-321

packages/mcp/test/security/env-security-simple.test.ts:187

SSH_PRIVATE_KEY: '-----BEGIN RSA PRIVATE KEY-----...',

LOWInventory / provenance · inv.hidden_file · CWE-1104

.mcp-funnel.example.json

.mcp-funnel.example.json

Why it matters. hidden member outside the usual dotfiles

Fix. review its purpose

LOWInventory / provenance · inv.hidden_file · CWE-1104

.prettierignore

.prettierignore

Why it matters. hidden member outside the usual dotfiles

Fix. review its purpose

LOWInventory / provenance · inv.hidden_file · CWE-1104

.yarnrc.yml

.yarnrc.yml

Why it matters. hidden member outside the usual dotfiles

Fix. review its purpose

LOWInventory / provenance · inv.symlink · CWE-1104

CLAUDE.md

CLAUDE.md

Why it matters. link not followed

LOWInventory / provenance · inv.symlink · CWE-1104

README.md

README.md

Why it matters. link not followed

LOWInventory / provenance · inv.symlink · CWE-1104

packages/mcp/README.md

packages/mcp/README.md

Why it matters. link not followed

LOWFilesystem / path · fs.traversal · CWE-22, CWE-59

packages/auth/src/__tests__/base-oauth-provider/ensure-valid-token.test.ts:3

import { AuthenticationError } from '../../errors/authentication-error.js';

LOWFilesystem / path · fs.traversal · CWE-22, CWE-59

packages/auth/src/__tests__/base-oauth-provider/handle-token-request-error.test.ts:3

import { AuthenticationError, OAuth2ErrorCode } from '../../errors/authentication-error.js';

LOWFilesystem / path · fs.traversal · CWE-22, CWE-59

packages/auth/src/__tests__/base-oauth-provider/process-token-response.test.ts:3

import { AuthenticationError } from '../../errors/authentication-error.js';

LOWFilesystem / path · fs.traversal · CWE-22, CWE-59

packages/auth/src/__tests__/base-oauth-provider/process-token-response.test.ts:4

import { AUTH_DEFAULT_EXPIRY_SECONDS } from '../../utils/index.js';

LOWFilesystem / path · fs.traversal · CWE-22, CWE-59

packages/auth/src/__tests__/base-oauth-provider/request-token-with-retry.test.ts:3

import { AuthenticationError, OAuth2ErrorCode } from '../../errors/authentication-error.js';

LOWSupply chain · supply.unpinned · CWE-829, CWE-1357

package.json

@modelcontextprotocol/sdk, zod, @eslint/js, @hono/zod-validator, @types/micromatch, @types/node, @typescript-eslint/eslint-plugin, @typescript-eslint/parser

Why it matters. 22 dependency range(s) float