API Change Feed

AIコーディングエージェントに、使用しているAPIやSDKの変更点を伝えます。対象は、コードが依存するバージョン以降における、人気ライブラリ38種（OpenAI、Anthropic、Stripe、Next.js、React、Nodeなど）の破壊的変更、非推奨化、セキュリティ修正です。無料ツールでは情報源と見出しを一覧表示し、アップグレードの確認はx402（Base上のUSDC）を通じて呼び出しごとに有料で利用できます。

workers.dev で表示

ホスト型 MCP サーバー

npx add-mcp 'https://changefeed.anthonyzilar.workers.dev/mcp'

Claude Code、Codex、Cursor などにインストールできます

ドキュメント

Try it: what changed since my version?

Add it to your coding agent

The quick check is free. Paid tools appear too; an agent with an x402 wallet can call them, others just use the free ones.

Claude Code

Run once in a terminal:

claude mcp add --transport http changefeed https://changefeed.dev/mcp

Cursor

Add to ~/.cursor/mcp.json (or.cursor/mcp.json in a project):

{
  "mcpServers": {
    "changefeed": {
      "url": "https://changefeed.dev/mcp"
    }
  }
}

VS Code

Add to.vscode/mcp.json:

{
  "servers": {
    "changefeed": {
      "type": "http",
      "url": "https://changefeed.dev/mcp"
    }
  }
}

Any HTTP agent

No install. Call:

GET https://changefeed.dev/v1/quick-check?package=express&from=4.21.0

Tell your agent when to use it

Agents call tools when their instructions say to. Paste this into CLAUDE.md, AGENTS.md or your Cursor rules:

Before writing or changing code that uses a third-party library or SDK, call the changefeed quick_check tool with the package name and the version this project uses (from package.json, requirements.txt or the lockfile). If it reports breaking changes or deprecations, call upgrade_check or read the release notes before writing code, and don't rely on memory for that library's API.

Pricing

Paid per call in USDC on Base through x402. No account, no key, no subscription. Errors and unknown packages are never charged.

HTTP	MCP tool	Price	Answers
`GET /v1/quick-check`	`quick_check`	free	Did anything break since my version? Verdict, counts and top headlines. About 20 a minute per client.
`GET /v1/upgrade-check`	`upgrade_check`	$0.01	Every breaking change, deprecation and security fix since your version, with the release-note sentence behind each.
`GET /v1/changes`	`get_changes`	$0.005	Change records for one API/SDK or all, filtered by date and kind.
`GET /v1/digest`	`digest`	$0.02	Everything breaking across all 60 sources since a date.
`GET /v1/sources`	`list_sources`	free	What we track and the package names to ask by.