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Permission Guard

Created By
luxemarasound-stack5 months ago
Content

402Found — Micro-utilities for the Agent Economy

Pay-per-use MCP servers for AI agents. No subscriptions. No API keys. Just x402 micropayments.

x402 MCP A2A 18 Tools MIT License


Table of Contents


What is 402Found?

402Found is a fleet of 18 remote MCP servers built for the agent economy. Each server solves one specific problem agents face in production — from cost runaway to prompt injection to PII leaks — and charges a fraction of a cent per use via the x402 payment protocol.

No signup. No monthly bill. Agents call the tool, pay for what they use, and move on.

Key properties:

  • Streamable-HTTP transport — works with any MCP-compatible client
  • x402 micropayments — sub-cent pricing, pay only for what you use
  • A2A compatible — agent cards hosted at card-registry.402found.dev
  • Stateless — no session state, no API keys to rotate
  • Production-ready — deployed, monitored, and live at https://{tool}.402found.dev/mcp

Quick Start

Add any tool to your MCP client config:

{
  "mcpServers": {
    "pii-scrubber": {
      "type": "streamable-http",
      "url": "https://pii-scrubber.402found.dev/mcp"
    }
  }
}

Add multiple tools at once:

{
  "mcpServers": {
    "pii-scrubber": {
      "type": "streamable-http",
      "url": "https://pii-scrubber.402found.dev/mcp"
    },
    "budget-ceiling-enforcer": {
      "type": "streamable-http",
      "url": "https://budget-ceiling-enforcer.402found.dev/mcp"
    },
    "prompt-injection-detector": {
      "type": "streamable-http",
      "url": "https://prompt-injection-detector.402found.dev/mcp"
    },
    "loop-gate": {
      "type": "streamable-http",
      "url": "https://loop-gate.402found.dev/mcp"
    }
  }
}

All servers use streamable-http transport and are live at https://{tool-name}.402found.dev/mcp. Requests without a valid x402 payment header return HTTP 402 Payment Required.


The Fleet (18 Tools)

Security & Safety

ToolWhat it doesPriceEndpoint
pii-scrubberStrips SSNs, emails, API keys, phone numbers, addresses, credit cards, and IPs from text. GDPR/HIPAA aligned.$0.005/reqlive
data-sentinelDeep second-pass scan for sensitive data that slipped through PII scrubbing. Catches JWTs, keys, connection strings, and internal IPs.$0.003/reqlive
prompt-injection-detectorScans agent input for prompt injection attacks — instruction overrides, jailbreaks, role-play manipulation, system prompt leakage, and hidden instructions.$0.003/reqlive
permission-guardChecks if an agent's requested action exceeds its defined scope. Detects privilege escalation and flags dangerous operations.$0.002/reqlive
hallucination-detectorScores AI output for likely hallucinated facts. Detects fabricated precision, invented citations, temporal impossibilities, and overconfident absolutes.$0.003/reqlive

Cost & Budget Control

ToolWhat it doesPriceEndpoint
budget-ceiling-enforcerPrevents runaway cloud costs. Enforces hard budget limits with configurable actions: throttle, pause, alert, or kill. Spend projection and webhook alerts included.$0.02/checklive
agent-cost-meterTracks cumulative agent session spend against budget ceilings. Calculates cost from token usage and API calls, returns budget status with recommendations.$0.002/reqlive

Agent Reliability

ToolWhat it doesPriceEndpoint
loop-gateDetects and breaks recursive agent loops using Bloom-filter detection. Paid reset to resume a halted loop.$0.005/resetlive
rate-limit-managerManages agent request rate limiting with sliding window and exponential backoff. Prevents rate limit errors when calling external APIs.$0.001/reqlive
performance-baseline-trackerCaptures and monitors AI agent output quality over time. Baseline snapshots, multi-metric drift detection, semantic similarity scoring, and trend analysis.$0.10/comparelive

Code & Output Quality

ToolWhat it doesPriceEndpoint
code-quality-scannerDetects vibe-code anti-patterns in AI agent code before production deployment. AST-powered analysis for Python, JavaScript, and LLM prompts.$0.05/scanlive
token-squeezerCompresses text into LLM-optimized Reasoning Maps. Saves 80%+ on context window token costs.$0.001/reqlive
format-converterConverts between JSON, CSV, XML, YAML, Markdown, HTML, and TOML. Handles nested JSON flattening. Zero external dependencies.$0.001/convlive

Agent Identity & Registry

ToolWhat it doesPriceEndpoint
agent-registryCentral inventory of all deployed AI agents. Register, query, monitor health, generate compliance reports, export CSV/JSON, and visualize dependency graphs.$0.001/querylive
card-registryHosts agent-card.json files at permanent public URLs. Discoverable by any A2A-compatible agent.$0.001/molive
the-prospectorGenerates valid A2A agent cards for any website from stable structured sources. Never scrapes.$0.01/cardlive
multi-agent-trust-verifierVerifies trust between agents by checking goal alignment, spend limits, and action scope. Detects goal drift and hijack attempts. OWASP ASI01 coverage.$0.004/reqlive
agent-audit-trailCreates tamper-evident, HMAC-signed audit log entries for agent actions. Returns signed receipts the caller stores for compliance.$0.001/loglive

How Payments Work

402Found uses the x402 micropayment protocol. When an agent calls a tool:

  1. Without a payment header — receives HTTP 402 Payment Required with payment details
  2. Agent attaches a valid x402 payment header — request is processed
  3. Cost is deducted at the per-request rate shown above

No wallets to set up manually — x402-compatible agent frameworks handle this automatically.

Resources:


Live Endpoints

All 18 tools are live. The base URL pattern is:

https://{tool-name}.402found.dev/mcp
ToolEndpoint
pii-scrubberhttps://pii-scrubber.402found.dev/mcp
data-sentinelhttps://data-sentinel.402found.dev/mcp
prompt-injection-detectorhttps://prompt-injection-detector.402found.dev/mcp
permission-guardhttps://permission-guard.402found.dev/mcp
hallucination-detectorhttps://hallucination-detector.402found.dev/mcp
budget-ceiling-enforcerhttps://budget-ceiling-enforcer.402found.dev/mcp
agent-cost-meterhttps://agent-cost-meter.402found.dev/mcp
loop-gatehttps://loop-gate.402found.dev/mcp
rate-limit-managerhttps://rate-limit-manager.402found.dev/mcp
performance-baseline-trackerhttps://performance-baseline-tracker.402found.dev/mcp
code-quality-scannerhttps://code-quality-scanner.402found.dev/mcp
token-squeezerhttps://token-squeezer.402found.dev/mcp
format-converterhttps://format-converter.402found.dev/mcp
agent-registryhttps://agent-registry.402found.dev/mcp
card-registryhttps://card-registry.402found.dev/mcp
the-prospectorhttps://the-prospector.402found.dev/mcp
multi-agent-trust-verifierhttps://multi-agent-trust-verifier.402found.dev/mcp
agent-audit-trailhttps://agent-audit-trail.402found.dev/mcp

Directories

Find 402Found tools on every major MCP registry:

DirectoryLink
Smithery.aiAll 18 tools under found402
MCP.soAll 18 tools listed
Cursor DirectoryAll 18 tools listed
Glama.aiRegistered

Built For

  • AI agent developers building with Claude, GPT-4, Gemini, or open models
  • Teams running multi-agent pipelines in production
  • Anyone who has watched an agent loop forever, leak PII, or run up a $200 cloud bill overnight
  • Developers exploring the A2A protocol and agent interoperability

Contributing

Contributions, issues, and feature requests are welcome. If you have an idea for a new micro-utility that fits the pay-per-use model:

  1. Open an issue describing the tool and its use case
  2. Follow the existing folder structure (one folder per tool, matching the slug)
  3. Include a README.md in the tool folder with pricing and endpoint info
  4. Submit a pull request

License

MIT — use freely, build on top, contributions welcome.

402Found is part of the Luxemara ecosystem.

Server Config

{
  "mcpServers": {
    "permission-guard": {
      "type": "streamable-http",
      "url": "https://permission-guard.402found.dev/mcp"
    }
  }
}
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