How do I install Agentpay Sentinel?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does Agentpay Sentinel need an API key?

No required environment variable is listed on this record.

What transport does Agentpay Sentinel use?

Agentpay Sentinel runs locally over stdio.

When was Agentpay Sentinel last checked?

Last checked 2026-11-09. Security guardrails for AI agent payments

Agentpay Sentinel MCP server

Power your agent

Add this server

Install from the publisher. Not a PlugMCP endpoint.

Run on PlugMCP

Host a copy with our keys and logs.

No packaged release in the registry yet. Follow the repository README.

RepositoryPublisher installStep-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

Server facts

Local

Transport: stdio
Version: 1.0.0
Last checked

Tools

No tool list yet. Remote servers get one after the first health check.

FAQ

Questions

AgentPay Sentinel MCP

A watchdog MCP that validates every agent payment request against all 9 security checks before it executes — catching policy violations, replay attacks, amount tampering, revoked tokens, and budget overruns at call time.

What your agent can do

Run a pre-flight audit on any payment transaction before executing it — get PASS or BLOCKED with the specific check that failed
Validate token integrity: confirms the SHA-256 hash matches the expected merchant_id:amount binding, catching forged or tampered tokens
Enforce budget caps: rejects transactions where current_spend + amount > budget_cap and returns exact remaining budget
Check merchant allowlist membership and block purchases in restricted categories
Verify token expiry and rate limits before the payment fires
Simulate known attack vectors (token forgery, budget overflow, replay, merchant spoof, expiry bypass) and get the specific defense mechanism and detection method for each

Installation

Requires: Python 3.10+, mcp package.

pip install mcp

Claude Desktop — add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "agentpay-sentinel": {
      "command": "python",
      "args": ["/absolute/path/to/agentpay-sentinel-mcp/server.py"]
    }
  }
}

Cursor — add to .cursor/mcp.json in your project root:

{
  "mcpServers": {
    "agentpay-sentinel": {
      "command": "python",
      "args": ["/absolute/path/to/agentpay-sentinel-mcp/server.py"]
    }
  }
}

Tool Reference

Tool	Description	Key params
`sentinel_audit_transaction`	Run all 9 security checks; returns PASS/BLOCKED + SHA-256 audit hash	`token_hash`, `merchant_id`, `amount`, `current_spend`, `budget_cap` (required) · `nonce`, `token_id`, `approved_amount` (enable checks 7–9)
`sentinel_revoke_token`	Permanently revoke a token — all future audits with this `token_id` will BLOCK	`token_id`, `reason`
`sentinel_clear_nonce`	Remove a nonce from the replay store (for legitimate refunds/retries only)	`nonce`
`sentinel_verify_chain`	Verify a sequence of audit hashes forms an unbroken chain	`audit_hashes`, `expected_chain_root`
`sentinel_threat_model`	Simulate any named attack vector; returns severity, defence, and detection	`attack_vector`, `context`

All 9 checks run by `sentinel_audit_transaction`

#	Check	What it catches	Param
1	Token integrity	SHA-256 hash mismatch — forged tokens	`token_hash`
2	Budget enforcement	Spend exceeding cap	`current_spend`, `budget_cap`
3	Merchant allowlist	Payment to unlisted merchant	`allowlist`
4	Category restriction	Purchase in blocked category	`blocked_categories`
5	Expiry check	Expired token	`expires_at`
6	Rate limit	Too many calls per minute	`calls_this_minute`
7	Amount mismatch	Agent changed amount after human approved	`approved_amount`
8	Replay attack	Same nonce used twice (file-backed store)	`nonce`
9	Revocation evasion	Agent using a revoked token	`token_id`

Checks 7–9 activate when the corresponding param is passed. State persists to ~/.sentinel/.

Attack vectors in `sentinel_threat_model`

token_forgery · budget_overflow · replay_attack · amount_mismatch · revocation_evasion · merchant_spoof · expiry_bypass

Security

sentinel_audit_transaction returns an advisory verdict — it does not intercept network traffic. Your agent is responsible for calling it before executing a payment and halting on BLOCKED. The audit hash returned is a SHA-256 digest of all check results, giving you a tamper-evident record of each pre-flight decision.

Pricing

Plan	Price	Included
Free	$0	50 audits/month
Pro	$19/month	Unlimited audits + threat model simulations

Upgrade to Pro

License

MIT — AgentPay Labs. Source: github.com/Rumblingb/agentpay-sentinel-mcp

Add this server

Host a copy with our keys and logs.

Server facts

Tools

Questions

How do I install Agentpay Sentinel?

Does Agentpay Sentinel need an API key?

What transport does Agentpay Sentinel use?

When was Agentpay Sentinel last checked?

Documentation

AgentPay Sentinel MCP

What your agent can do

Installation

Tool Reference

All 9 checks run by sentinel_audit_transaction

Attack vectors in sentinel_threat_model

Security

Pricing

License

All 9 checks run by `sentinel_audit_transaction`

Attack vectors in `sentinel_threat_model`