# Forest Packages – Package Registry Change Detector

> Forest Packages – Package Registry Change Detector is a paid API for AI agents from http--forest-gas-station-mainnet--lcjl27p8lmjs.code.run, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-12).

Detects whether normalized npm or PyPI package metadata has changed since a saved SHA-256 fingerprint, covering version existence, deprecation, license, and runtime requirements.

## Facts

- Endpoint: POST https://http--forest-gas-station-mainnet--lcjl27p8lmjs.code.run/package/changed?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/forest-packages-package-registry-change-detector-7856c843
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KURkgDYjZC1D9KySs2UQw

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 forest-packages-package-registry-change-detector-7856c843 -d '<json body>'
```

Example prompt: Check whether the npm package lodash at version 4.17.21 has had any material public registry changes — deprecation, license, or latest version — since this previous hash: a3f1c2d4e5b6789012345678901234567890123456789012345678901234abcd.

## When to prefer this

Choose this endpoint when you need a lightweight, deterministic way to poll whether a specific npm or PyPI package's public metadata (version availability, deprecation, license, runtime req) has drifted from a known-good state — without needing a full vulnerability scan, dependency resolution, or graph traversal. Ideal for CI/CD monitors, dependency bots, compliance checkers, and supply chain watchers that need cheap, fast, idempotent change signals rather than a full audit.

## Known failure modes

- Package not found in the specified ecosystem — returns error or null state
- Invalid previous_hash format (not 64 hex chars) — rejected by schema validation
- Ecosystem not supported beyond npm/pypi — request rejected
- Registry API timeout or upstream outage — transient failure
- Version string not found for the given package — may return empty or changed state
- Payment not attached or insufficient USDC — x402 payment required error

## How this service works

Detect whether normalized public npm or PyPI package registry state changed since a saved fingerprint. Returns a deterministic SHA-256 fingerprint for package/version existence, latest/resolved version, deprecation or yank state, license and runtime requirement. No dependency graph, vulnerability scan or registry mutation. Base mainnet USDC

## Output

Returns a deterministic SHA-256 fingerprint representing the current normalized public state of the package/version (version existence, latest/resolved version, deprecation or yank state, license, runtime requirements), plus a boolean or signal indicating whether the current state differs materially from the supplied previous_hash. No dependency graph, vulnerability data, or registry mutations are included.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "package": {
   "type": "string",
   "maxLength": 214,
   "minLength": 1,
   "description": "Public package name to inspect."
  },
  "version": {
   "type": "string",
   "maxLength": 128,
   "minLength": 1,
   "description": "Package version whose public metadata should be checked."
  },
  "ecosystem": {
   "enum": [
    "npm",
    "pypi"
   ],
   "description": "Public ecosystem value used to scope this lookup."
  },
  "previous_hash": {
   "type": [
    "string",
    "null"
   ],
   "pattern": "^[a-fA-F0-9]{64}$",
   "description": "Earlier result hash used to detect a material change."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/forest-packages-package-registry-change-detector-7856c843/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from http--forest-gas-station-mainnet--lcjl27p8lmjs.code.run](https://www.zero.xyz/host/http--forest-gas-station-mainnet--lcjl27p8lmjs.code.run/llms.txt)