Aggregated changelog across versions API

Resolves an npm package's GitHub repo and aggregates every GitHub release whose tag falls in (from, to] into one semver-ordered diff (version, date, prerelease flag, notes), plus a breaking-change flag and major-bump count. The value-add is the span aggregation + ordered selection across many releases that an agent would otherwise paginate by hand. Answers 'what changed between v2 and v3 of this package', 'aggregate release notes across versions', 'are there breaking changes upgrading', 'changelog from 1.0.0 to 2.0.0'.

Price$0.01per request

MethodPOST

Route/v1/dev/changelog

StatusLive

MIME typeapplication/json

Rate limit60/minute

Cache3600s public

devchangelogrelease-notesnpmgithubupgradediffversions

API URLhttps://x402.hexl.dev/v1/dev/changelog

Integration docs

Example request

{
  "package": "fastify",
  "from": "4.0.0",
  "to": "4.10.0"
}

Example response

{
  "package": "fastify",
  "repository": "https://github.com/fastify/fastify",
  "from": "4.0.0",
  "to": "4.10.0",
  "releaseCount": 2,
  "hasBreakingChanges": false,
  "majorVersionBumps": 0,
  "releases": [
    {
      "version": "v4.9.0",
      "name": "v4.9.0",
      "date": "2026-02-01T00:00:00Z",
      "prerelease": false,
      "url": "https://github.com/fastify/fastify/releases/tag/v4.9.0",
      "notes": "feat: add X"
    },
    {
      "version": "v4.10.0",
      "name": "v4.10.0",
      "date": "2026-03-01T00:00:00Z",
      "prerelease": false,
      "url": "https://github.com/fastify/fastify/releases/tag/v4.10.0",
      "notes": "fix: Y"
    }
  ]
}

Input schema

{
  "type": "object",
  "required": [
    "package",
    "from",
    "to"
  ],
  "properties": {
    "package": {
      "type": "string",
      "examples": [
        "fastify"
      ]
    },
    "from": {
      "type": "string",
      "examples": [
        "4.0.0"
      ]
    },
    "to": {
      "type": "string",
      "examples": [
        "4.10.0"
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}