# Screwtape.ai — Judge Agent as a Service (Duplicate Check)

> Screwtape.ai — Judge Agent as a Service (Duplicate Check) is a paid API for AI agents from screwtape.ai, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-29).

Evaluates agent output against a task and criteria to return a pass, fail, or retry verdict with a score and reasons, including duplicate detection.

## Facts

- Endpoint: POST https://screwtape.ai/v1/duplicate?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/screwtape-ai-judge-agent-as-a-service-duplicate-check-80fb6728
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nSROWtx0Cia6Rg6toJRjo

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability screwtape-ai-judge-agent-as-a-service-duplicate-check-80fb6728 -d '<json body>'
```

Example prompt: Judge whether my agent's output passes for this task: 'Summarize the Apollo 11 mission' — the output is 'The Apollo 11 crew of 4 landed on the Moon in July 1969 launching from Cape Canaveral', the criteria are ['mentions crew size','mentions launch site'], and the evidence is ['The crew size was 3.','The mission launched from Cape Canaveral.'] — retain the result for auditing.

## When to prefer this

Use this endpoint when you need automated, structured pass/fail/retry verdicts on AI agent outputs — especially when you want claim-level grounding against evidence, deterministic string checks without invoking an LLM, or audit trails via retention. Prefer this over generic LLM-based review when you need consistent, low-cost ($0.005/call) structured verdicts with machine-readable scores and reasons that downstream orchestration logic can act on.

## Known failure modes

- Missing required fields (task, agent_output, or criteria) returns a 400-level error
- Invalid agent_id format (not matching pattern) causes schema validation failure
- Duplicate submission detected may return a cached or flagged result
- Evidence mismatch where claims cannot be verified against supplied evidence lowers score and may trigger 'fail' or 'retry'
- Empty criteria array may result in trivially passing verdicts
- Service unavailability returns 5xx error

## How this service works

API for pass, fail, or retry verdicts on agent output, plus multi-agent consensus and false-consensus risk.

## Output

A JSON object containing a verdict ('pass', 'fail', or 'retry'), a numeric score (0–1), an array of human-readable reasons explaining the verdict, a unique request_id, the engine type used (e.g. 'deterministic'), and optional retention metadata if the result was stored.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "task": {
   "type": "string"
  },
  "retain": {
   "type": "boolean"
  },
  "version": {
   "type": "string",
   "maxLength": 64,
   "description": "Optional version tag for that agent."
  },
  "agent_id": {
   "type": "string",
   "pattern": "^[A-Za-z0-9._:-]{1,64}$",
   "maxLength": 64,
   "description": "Optional tag for the agent making this call."
  },
  "criteria": {
   "type": "array",
   "items": {
    "type": "string"
   }
  },
  "evidence": {
   "type": "array",
   "items": {
    "type": "string"
   }
  },
  "agent_output": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "schema": {
  "type": "object",
  "required": [
   "verdict",
   "score",
   "reasons",
   "request_id"
  ],
  "properties": {
   "score": {
    "type": "number"
   },
   "engine": {
    "type": "string"
   },
   "reasons": {
    "type": "array",
    "items": {
     "type": "string"
    }
   },
   "verdict": {
    "enum": [
     "pass",
     "fail",
     "retry"
    ],
    "type": "string"
   },
   "retention": {
    "type": "object"
   },
   "request_id": {
    "type": "string"
   }
  }
 },
 "example": {
  "score": 0.9,
  "checks": [],
  "claims": [
   {
    "text": "The crew size was 4.",
    "status": "supported"
   },
   {
    "text": "The mission launched from Cape Canaveral.",
    "status": "supported"
   }
  ],
  "engine": "deterministic",
  "reasons": [
   "2 of 2 claims are grounded in the supplied evidence.",
   "2 of 2 criteria matched the output.",
   "Deterministic string checks only. No model was called."
  ],
  "verdict": "pass",
  "retention": {
   "retained": false
  },
  "request_id": "example-request-id",
  "verification": "heuristic"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/screwtape-ai-judge-agent-as-a-service-duplicate-check-80fb6728/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from screwtape.ai](https://www.zero.xyz/host/screwtape.ai/llms.txt)