Is Screwtape Examples free?

Yes, Screwtape Examples is free to use.

How do I install Screwtape Examples?

Screwtape Examples is a remote plugin. You do not need to install anything locally. Add the server URL to your AI app's MCP configuration and you are ready to go.

Is Screwtape Examples safe to use?

Yes. Screwtape Examples passed MCP Marketplace's automated security scan with a score of 9.9/10 (low risk). Every server on MCP Marketplace is security-scanned before it's listed; see the full security report on this page for the findings and permissions.

What AI apps work with Screwtape Examples?

Screwtape Examples uses the Model Context Protocol (MCP) and works with any MCP-compatible AI app, including Claude, ChatGPT / Codex, Gemini, Copilot, Cursor, and more.

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Screwtape Examples MCP Server

by Screwtapeai

Developer ToolsLow Risk9.9MCP RegistryRemote

Free

Server data from the Official MCP Registry

Checks if an AI agent may pay: duplicate invoices, totals, evidence. Signed receipts.

About

Checks if an AI agent may pay: duplicate invoices, totals, evidence. Signed receipts.

Remote endpoints: streamable-http: https://screwtape.ai/mcp

Security Report

9.9

Low Risk9.9Low Risk

Valid MCP server (1 strong, 0 medium validity signals). No known CVEs in dependencies. Imported from the Official MCP Registry. 1 finding(s) downgraded by scanner intelligence.

Endpoint verified · Open access · 1 issue found

Security scores are indicators to help you make informed decisions, not guarantees. Always review permissions before connecting any MCP server.

Permissions Found in Source Code

Found by scanning the linked source code. This listing connects to a hosted endpoint, so none of this runs on your machine: it describes what the server software does where it is hosted.

env_vars

Applies to the server that hosts this plugin, not to your machine.

HTTP Network Access

Connects to external APIs or services over the internet.

How to Connect

Remote Plugin

No local installation needed. Your AI client connects to the remote endpoint directly.

Add this to your MCP configuration to connect:

{
  "mcpServers": {
    "ai-screwtape-screwtape": {
      "url": "https://screwtape.ai/mcp"
    }
  }
}

Documentation

View on GitHub

From the project's GitHub README.

Screwtape.ai examples

Copy-paste examples that stop an AI agent from paying the wrong invoice. Each one calls the public Screwtape.ai API with an API key and does two things before money moves:

Spend check: the line items and tax must add up to the total, and the invoice must match your evidence (purchase order, contract, approval email). You get a verdict and a signed receipt.
Duplicate-invoice check: the same invoice, or the same vendor and amount within a few days, is flagged before the agent pays it twice.

The agent pays only when next_step.action is pass. Anything else (retry or escalate) means do not pay.

Folder	Stack	Run
`curl/`	curl + jq	`./curl/check_payment.sh`
`python/`	Python 3.9+, standard library only	`python python/check_payment.py`
`typescript/`	Node 18+, built-in fetch	`cd typescript && npm i && npm start`
`langchain/`	LangChain tool	`python langchain/spend_tool.py`
`crewai/`	CrewAI tool	`python crewai/spend_tool.py`
`openai-agents/`	OpenAI Agents SDK, guarded payment tool	`python openai-agents/spend_guard.py`

Start in one minute

export SCREWTAPE_API_KEY=...   # free key: https://screwtape.ai/signup/
python python/check_payment.py

Expected output (receipt ids differ per run):

first:  verdict=pass action=pass reason=none duplicate=unique receipt=...
  -> PAY
second: verdict=... action=escalate reason=duplicate_invoice duplicate=duplicate receipt=...
  -> DO NOT PAY
wrong total: verdict=fail action=... reason=sum_mismatch duplicate=... receipt=...
  -> DO NOT PAY

The one rule your agent needs

result = check_payment(invoice, evidence)        # POST https://screwtape.ai/v1/duplicate
if result["next_step"]["action"] != "pass":
    stop_and_escalate(result)                    # do not pay

Put the check inside the payment tool itself (see openai-agents/), so the model cannot skip it.

API in brief

POST /v1/duplicate: spend check plus duplicate-invoice check (used by every example here).
POST /v1/judge: verdict on any agent output, with deterministic checks (sum, required_fields, json_schema, regex, equals, ...). See checks.
POST /v1/consensus: compare 2 to 16 agent answers before acting on them.
POST /v1/receipts/verify: verify a signed receipt.
Auth: Authorization: Bearer $SCREWTAPE_API_KEY. Add an Idempotency-Key header to make retries safe.
Full spec: openapi.json. Docs: screwtape.ai/docs.

MCP

Agents that speak MCP can connect directly: https://screwtape.ai/mcp (Streamable HTTP, Bearer key). Tools: judge, check_duplicate_invoice, consensus.

Pricing

Free: 10 calls a day, no card.
Sandbox Evaluation Pack: $100 for 2,000 checks.
Enterprise pilot: support@screwtape.ai

Details: screwtape.ai/pricing.

License

MIT

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4.8

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