# Toll402 LLM-as-Judge

> Toll402 LLM-as-Judge is a paid API for AI agents from toll402.dev, paid per call via x402, $0.07/call, status unknown (last checked 2026-09-14).

Scores a candidate output against a task and criteria (0–100) using an independent LLM judge, returning pass/fail, per-criterion scores, issues, and improvement suggestions.

## Facts

- Endpoint: GET https://toll402.dev/v1/judge
- Price: $0.07/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/toll402-llm-as-judge-0fa94051
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_OIoSlxUR07cfMlewnNHM7

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 toll402-llm-as-judge-0fa94051
```

Example prompt: Can you judge my draft response against the original task? Task: 'Explain how photosynthesis works for a 10-year-old.' Candidate: 'Plants eat sunlight using chlorophyll, turning CO2 and water into sugar and oxygen.' Score it on correctness, completeness, and clarity, and let me know if it passes.

## When to prefer this

Choose this endpoint when you need an independent, structured numeric judgment of an LLM output rather than just a binary check — especially for self-verification loops, best-of-N selection, or QA gates in agentic pipelines. It is particularly useful when you want per-criterion breakdowns with rationale and actionable suggestions, rather than a simple pass/fail or raw similarity score.

## Known failure modes

- Missing required 'task' or 'candidate' query parameters returns a validation error
- Candidate or task text exceeding 100,000 or 20,000 character limits respectively causes rejection
- Criteria array with fewer than 1 or more than 10 items returns a schema validation error
- Network timeout or upstream LLM unavailability may return a 5xx error
- Ambiguous or very short task descriptions may produce unreliable or low-confidence scores

## How this service works

Independent LLM-as-judge: scores a candidate output against a task and criteria (0-100), with pass/fail, issues and suggestions. Use it for self-verification, best-of-N, or QA gates.

## Output

Returns a JSON object with an overall integer score (0–100), a boolean pass/fail verdict, an array of per-criterion scores each with criterion name, integer score, and rationale, a list of identified issues, and a list of improvement suggestions. Also includes elapsed time in milliseconds and the tool name used.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "task",
      "candidate"
     ],
     "properties": {
      "task": {
       "type": "string",
       "maxLength": 20000,
       "description": "The task/instructions the candidate was supposed to fulfil"
      },
      "criteria": {
       "type": "array",
       "items": {
        "type": "string",
        "maxLength": 300
       },
       "default": [
        "correctness",
        "completeness",
        "clarity"
       ],
       "maxItems": 10,
       "minItems": 1
      },
      "candidate": {
       "type": "string",
       "maxLength": 100000,
       "description": "The output to evaluate"
      },
      "reference": {
       "type": "string",
       "maxLength": 100000,
       "description": "Optional gold/reference answer"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "ms": {
       "type": "integer"
      },
      "ok": {
       "type": "boolean"
      },
      "tool": {
       "type": "string"
      },
      "result": {
       "type": "object",
       "properties": {
        "pass": {
         "type": "boolean"
        },
        "issues": {
         "type": "array",
         "items": {}
        },
        "scores": {
         "type": "array",
         "items": {
          "type": "object",
          "properties": {
           "score": {
            "type": "integer"
           },
           "criterion": {
            "type": "string"
           },
           "rationale": {
            "type": "string"
           }
          }
         }
        },
        "overall": {
         "type": "integer"
        },
        "suggestions": {
         "type": "array",
         "items": {}
        }
       }
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "pass": true,
  "issues": [],
  "scores": [
   {
    "score": 90,
    "criterion": "is a haiku (5-7-5)",
    "rationale": "..."
   }
  ],
  "overall": 88,
  "suggestions": []
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/toll402-llm-as-judge-0fa94051/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from toll402.dev](https://www.zero.xyz/host/toll402.dev/llms.txt)