# SOP Step Evidence Validator

> SOP Step Evidence Validator is a paid API for AI agents from agent-sop-compiler-production.up.railway.app, paid per call via x402, $0.25/call, status unknown (last checked 2026-09-14).

Verifies that every step in a compiled SOP document has exact supporting source evidence from provided source texts

## Facts

- Endpoint: POST https://agent-sop-compiler-production.up.railway.app/v1/validate
- Price: $0.25/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sop-step-evidence-validator-86d4c8c0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ivGnBBeDOIfpDLe0GsjAb

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 sop-step-evidence-validator-86d4c8c0 -d '<json body>'
```

Example prompt: Can you validate this compiled SOP document against my three source texts to make sure every step has exact supporting evidence? Here are the sources: [source id='src-1' name='FDA Guidance 2023' content='...'], [source id='src-2' name='Internal Policy v4' content='...'], and the compiled SOP document object I got from the compiler.

## When to prefer this

Use this endpoint after first compiling an SOP with the sibling compile endpoint, to confirm every step is traceable to exact source evidence before publishing or acting on the SOP. Prefer this over manual review when you have up to 12 structured source documents and need a programmatic evidence audit.

## Known failure modes

- Missing required 'document' field returns validation error
- Fewer than 1 source provided causes schema rejection
- More than 12 sources provided exceeds maxItems limit
- Source object missing required 'id', 'name', or 'content' fields causes rejection
- Malformed SOP document object causes parsing failure
- Payment not included or insufficient USDC returns 402 Payment Required

## How this service works

Verify that every SOP step has exact supporting source evidence

## Output

A validation report indicating which SOP steps are supported by exact evidence from the provided sources, which steps lack supporting evidence, and citations linking each step back to the relevant source by ID and name.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "required": [
      "document",
      "sources"
     ],
     "properties": {
      "sources": {
       "type": "array",
       "items": {
        "type": "object",
        "required": [
         "id",
         "name",
         "content"
        ],
        "properties": {
         "id": {
          "type": "string",
          "description": "Stable source identifier"
         },
         "name": {
          "type": "string",
          "description": "Human-readable source name"
         },
         "content": {
          "type": "string",
          "description": "Inline source text; redact all credentials"
         }
        }
       },
       "maxItems": 12,
       "minItems": 1
      },
      "document": {
       "type": "object",
       "description": "Previously compiled SOP document"
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sop-step-evidence-validator-86d4c8c0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent-sop-compiler-production.up.railway.app](https://www.zero.xyz/host/agent-sop-compiler-production.up.railway.app/llms.txt)