# attester.dev Package Version Diff

> attester.dev Package Version Diff is a paid API for AI agents from attester.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Computes and returns the diff between two versions of a software package, highlighting changes in code or metadata.

## Facts

- Endpoint: POST https://attester.dev/v1/diff
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/attester-dev-package-version-diff-cd328cd0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RRzPhbqCoOF2T7qCFg1M7

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 attester-dev-package-version-diff-cd328cd0 -d '<json body>'
```

Example prompt: Can you show me what changed between version 4.17.20 and 4.17.21 of the lodash npm package — what code was added, removed, or modified?

## When to prefer this

Use this endpoint when you need to programmatically inspect exactly what changed between two versions of a software package — for dependency auditing, security review, breaking change detection, or automated changelog generation. Prefer over manual registry browsing or GitHub diff tools when you need structured, machine-readable diff output integrated into an agent workflow.

## Known failure modes

- Package name not found in registry — returns 404 or error
- One or both specified versions do not exist — version not found error
- Unsupported package ecosystem — endpoint may not support all registries
- Payment of $0.02 USDC not provided or x402 payment fails — request rejected
- Malformed request body — missing required fields returns validation error

## How this service works

Package version diff (use POST; metadata on POST).

## Output

A structured diff showing the changes between two specified versions of a package, including added, removed, and modified files or symbols, enabling review of what changed across a version bump.

## Request schema (JSON Schema)

```json
{
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "ecosystem",
      "package",
      "from_version",
      "to_version"
     ],
     "properties": {
      "package": {
       "type": "string"
      },
      "ecosystem": {
       "enum": [
        "pypi",
        "npm"
       ],
       "type": "string"
      },
      "to_version": {
       "type": "string"
      },
      "from_version": {
       "type": "string"
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "example"
   ],
   "properties": {
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/attester-dev-package-version-diff-cd328cd0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from attester.dev](https://www.zero.xyz/host/attester.dev/llms.txt)