MCP server · operational

agentguard

Hosted MCP policy proxy for agent fleets: per-run spend caps, kill switch, loop breaker, dry-run of destructive writes with a diff, and a hash-chained audit log.

agentguard hosted is a hard stop between an agent fleet and the bill: spend caps and a kill switch per run, loops broken before they bill, destructive writes faked in dry-run with the diff, and a hash-chained audit log with published daily Merkle roots. agentguard_get_pricing and agentguard_spend_report need no key; agentguard_spend_report reads an agent log (Claude Code .jsonl, CSV or an agentguard audit export) and reports spend, loops and the band whose cap would have stopped each overspend, storing nothing. An agent can start the free trial with no human and no card: POST https://agentwares-agentguard.vercel.app/api/v1/signup {"accept_terms": true} returns an account key; then agentguard_create_proxy puts a per-customer proxy in front of an MCP server. Every refusal is an isError result whose text is JSON {code, cause, fix, retryable}: LOOP_DETECTED, CAP_EXCEEDED, BAND_EXCEEDED, APPROVAL_REQUIRED, KILL_SWITCH, TOOL_DENIED. Monthly bands are bought at a Stripe Checkout page by a person; an unattended agent can instead buy calls outright at $0.00029/call with a prepaid credit key funded in USDC over x402. Open-source self-hosted proxy: npx @agentwares/agentguard.

endpoint: https://agentwares-agentguard.vercel.app/api/mcp
auth: none for pricing and spend report; Bearer account key for the rest
try it: tested example call
curl -s https://agentwares-agentguard.vercel.app/api/mcp -H "content-type: application/json" -H "accept: application/json, text/event-stream" -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"agentguard_get_pricing","arguments":{}}}'
capabilities: create-proxy · set-policy · cap-spend · kill-switch · break-loops · dry-run-writes · get-run · export-audit · recommend-allowlist · spend-report · get-pricing
tags: agents · security · spend · mcp · audit · guardrails
pricing: Free trial; Starter $29/mo, Pro $99/mo, Team $299/mo; or $0.00029/call
i/o: application/json (JSON-RPC over Streamable HTTP) → application/json
docs: https://agentwares-agentguard.vercel.app/llms.txt
machine-readable: /api/public/registry/agentguard-mcp

Follow this tool

Get an alert when agentguard goes down, comes back, or quietly changes shape (response schema or tool list). Free for up to 3 tools. Pro: 100 tools + webhooks for your agents.

Get a key in one call

No account, no email, no dashboard

100 calls/day anonymous · 1,000/day with this free key · 50,000/day on Agent Pro. The key is returned instantly in the response — send it as the x-api-key header on any /api/public/* request. The key also lets you follow up to 3 tools and get an alert when one goes down or quietly changes shape.

tested example call

curl -s -X POST https://agentnexus.app/api/public/keys \
  -H 'content-type: application/json' \
  -d '{"agent":"my-agent","purpose":"tool discovery"}'

Use it from your agent

Point any MCP-capable agent (Claude, Cursor, your own) at the no-auth endpoint — it can then find agentguard and the rest of the registry on its own:

tested example call

claude mcp add --transport http agent-nexus https://agentnexus.app/api/public/mcp

Agents can discover agentguard through the Agent Nexus MCP server, /llms.txt or the discovery API.