# nbx4 Contract Observations Report Fetch

> nbx4 Contract Observations Report Fetch is a paid API for AI agents from nbx4.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-11-01).

Retrieves a block-pinned, immutable smart contract observation report for a given report ID across 16 EVM mainnets

## Facts

- Endpoint: GET https://nbx4.dev/v3/report?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nbx4-contract-observations-report-fetch-ebe4e26f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9CLfja0p9QQUHtUR_Ne-u

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 nbx4-contract-observations-report-fetch-ebe4e26f
```

Example prompt: Pull the nbx4 v3 contract observation report with ID nbx4_v3_0d0d93c231b6e7e2eb022eda3edc3abdf7fda8b3eb84bae630fd8320a042dbc0 and show me the findings and block it was pinned to.

## When to prefer this

Use this endpoint when you have already obtained a report ID from POST /v3/prepare and need to retrieve the immutable, block-pinned findings for a specific EVM smart contract. Prefer this over re-running a full analysis when you need a reproducible, auditable snapshot tied to a specific block hash across any of the 16 supported EVM mainnets.

## Known failure modes

- Invalid or malformed report_id (does not match ^nbx4_v3_[0-9a-f]{64}$) returns a 400 error
- Report ID not found or not yet prepared returns a 404 error
- Payment not received or x402 payment flow incomplete returns a 402 Payment Required
- Network or upstream RPC failure on the relevant EVM chain returns a 503 or timeout
- Rate limiting may apply for rapid successive reads

## How this service works

Review risk-relevant preliminary, limited mechanism evidence before integrating an EVM token: block-pinned source-syntax hints and observed state for mint, pause, blacklist, transfer limits, fee/tax and proxy mechanisms, with optional V2 pool observations. Free POST /v3/prepare returns report_id; paid GET /v3/report reads stored JSON for 0.01 USDC on Base. Unknowns remain unknown; not a security audit or sellability verdict.

## Output

Returns a JSON object containing the report ID, report digest (SHA-256 hex), block hash, block number, chain ID, contract address, policy version, and a findings object with block-pinned contract observations and explicit unknowns. The full paid report includes preliminary findings and unknowns not visible in the free envelope.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "report_id"
     ],
     "properties": {
      "report_id": {
       "type": "string",
       "pattern": "^nbx4_v3_[0-9a-f]{64}$",
       "description": "ID of an existing immutable v3 report returned by POST /v3/prepare; this is a public sample."
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "reportId",
      "reportDigest"
     ],
     "properties": {
      "address": {
       "type": "string",
       "pattern": "^0x[0-9a-f]{40}$"
      },
      "chainId": {
       "type": "integer"
      },
      "finding": {
       "type": "object",
       "properties": {
        "threat_analysis": {
         "type": "object",
         "properties": {
          "severity": {
           "enum": [
            "REVIEW",
            "INDETERMINATE"
           ],
           "type": "string"
          },
          "mechanisms": {
           "type": "object",
           "properties": {
            "mint": {
             "type": "object",
             "properties": {
              "status": {
               "enum": [
                "observed_signal",
                "unknown"
               ],
               "type": "string"
              },
              "evidence": {
               "type": "array",
               "items": {
                "type": "object"
               }
              }
             },
             "description": "Pinned evidence or an explicit unknown, not a safety verdict."
            },
            "pause": {
             "type": "object",
             "properties": {
              "status": {
               "enum": [
                "observed_signal",
                "unknown"
               ],
               "type": "string"
              },
              "evidence": {
               "type": "array",
               "items": {
                "type": "object"
           
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "reportId": "nbx4_v3_9846634448486c5bf601313396b111fdbae6fd3586d4ba088fd598f04bca7a09",
  "reportDigest": "9846634448486c5bf601313396b111fdbae6fd3586d4ba088fd598f04bca7a09"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nbx4-contract-observations-report-fetch-ebe4e26f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from nbx4.dev](https://www.zero.xyz/host/nbx4.dev/llms.txt)