# NuGet Package Health Check

> NuGet Package Health Check is a paid API for AI agents from package-registries.x402tookit.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-30).

Returns health metadata for a .NET NuGet package including latest release age, download count, verified owner status, deprecation flag, and known vulnerability indicators.

## Facts

- Endpoint: GET https://package-registries.x402tookit.com/nuget-health?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nuget-package-health-check-c6cc1a3a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_d1I95PrZHxCIB2F2eg0W9

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 nuget-package-health-check-c6cc1a3a
```

Example prompt: Can you check the health of the Newtonsoft.Json NuGet package — I want to know if it's still actively maintained, whether it has any known vulnerabilities, and if the owner is verified?

## When to prefer this

Use this endpoint when you need authoritative health metadata specifically for .NET NuGet packages, including vulnerability status, owner verification, and maintenance freshness. Prefer this over generic npm or PyPI endpoints when the dependency is a .NET/C# library. It is ideal for automated dependency auditing pipelines, security reviews before adding a package to a project, or comparing library vitality.

## Known failure modes

- Package ID not found on NuGet — returns null or empty result
- NuGet registry temporarily unavailable — may return degraded flag with partial data
- Malformed package ID input — validation error
- Rate limiting or upstream API errors — may return error or degraded response

## How this service works

Health of a .NET NuGet package: latest release age, downloads, verified owner, deprecation and known-vulnerability flags.

## Output

Returns a structured object with the package ID, latest version string, date of latest publish, days since latest release, total download count, list of owners, authors, license identifier, project URL, verified prefix flag, deprecation details (if any), known vulnerability entries, a verdict summary, and any reasons or caveats. Also includes flags for degraded data availability and fields that could not be checked.

## 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": [
      "id"
     ],
     "properties": {
      "id": {
       "type": "string",
       "description": "Package id, e.g. Newtonsoft.Json"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "id": {
       "type": [
        "null",
        "string"
       ]
      },
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "tags": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "listed": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "owners": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "authors": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "license": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "sourceUrl": {
       "type": [
        "null",
        "string"
       ]
      },
      "deprecated": {},
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "projectUrl": {
       "type": [
        "null",
        "string"
       ]
    
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nuget-package-health-check-c6cc1a3a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from package-registries.x402tookit.com](https://www.zero.xyz/host/package-registries.x402tookit.com/llms.txt)