# GET /changelog: $0.005 per call

What changed in a library or SDK since a date: every version published since then (npm, PyPI, crates, Go) and the release notes from its GitHub releases or CHANGELOG, newest first, with breaking-looking lines flagged. Works for any GitHub repository too (API SDKs, CLIs). ?name=openai&since=2026-09-01 or ?repo=stripe/stripe-node&since=2026-09-01

- **Price:** $0.005 in USDC, the same on Base, Solana, Polygon, Arbitrum. Failed calls are never charged.
- **Free trial:** yes, 20 free calls a day from Claude, Cursor or any MCP client ([set-up](/mcp/setup)).
- **Tier:** live
- **Answers cached for:** 1 hour(s)
- **Data sources:** deps.dev version dates (free); GitHub releases (free; GITHUB_TOKEN optional); ungh.cc (free); CHANGELOG files (free)
- **Lane:** AI coding agents ([OpenAPI](/openapi/coding.json))
- **Live health:** [status page](/status)

## Free sample

See an answer for the demo input first, free (no payment, 10 a minute): [https://aayatai.com/sample/changelog](/sample/changelog). It is a stored real answer when we have one, otherwise an example marked `"kind": "illustrative"`.

```bash
curl "https://aayatai.com/sample/changelog"
```

## 1. See the price (free)

Call it without paying: you get `402 Payment Required` and a `PAYMENT-REQUIRED` header with the exact price and where to pay.

```bash
curl -i "https://aayatai.com/changelog?ecosystem=npm&name=hono&since=2026-09-20"
```

## 2. Pay and call (TypeScript)

```bash
npm install @x402/fetch @x402/evm viem
```

```ts
import { wrapFetchWithPaymentFromConfig } from "@x402/fetch";
import { ExactEvmScheme } from "@x402/evm";
import { privateKeyToAccount } from "viem/accounts";

// A wallet used only by your agent, holding a little USDC on Base.
const account = privateKeyToAccount(process.env.WALLET_PRIVATE_KEY as `0x${string}`);
const pay = wrapFetchWithPaymentFromConfig(fetch, {
  schemes: [{ network: "eip155:8453", client: new ExactEvmScheme(account) }],
});

const res = await pay("https://aayatai.com/changelog?ecosystem=npm&name=hono&since=2026-09-20");
console.log(await res.json());
```

## 3. Or as an MCP tool

```ts
// MCP server: https://aayatai.com/mcp (Streamable HTTP). With the x402 MCP client (see /start):
const result = await client.callTool("changelog", {"ecosystem":"npm","name":"hono","since":"2026-09-20"});
```

## Inputs

- `ecosystem` (string; one of `npm`, `pypi`, `crates`, `go`; default `npm`): Package ecosystem: npm, pypi, crates (Rust) or go (Go modules).
- `name` (string): Package name (e.g. openai, stripe, boto3).
- `repo` (string): Or: a GitHub repository, owner/name or URL.
- `since` **(required)** (string): Date (YYYY-MM-DD or ISO time) to report changes after, up to 2 years back.

Bad inputs are rejected with HTTP 400 before any payment is asked for.

## Example answer

```json
{
  "target": {
    "ecosystem": "npm",
    "name": "hono"
  },
  "since": "2026-09-20",
  "repository": "https://github.com/honojs/hono",
  "latest": "4.13.9",
  "changed": true,
  "versions": [
    {
      "version": "4.13.9",
      "publishedAt": "2026-09-24T01:32:02Z"
    }
  ],
  "releases": [
    {
      "version": "4.13.9",
      "date": "2026-09-24T01:32:14Z",
      "source": "github-release",
      "url": "https://github.com/honojs/hono/releases/tag/v4.13.9",
      "notes": "## What's Changed\n* fix(jsx): ...",
      "breaking": []
    }
  ],
  "omitted": 0,
  "breakingHints": [],
  "source": "GitHub releases",
  "fetchedAt": "2026-09-28T12:00:00.000Z"
}
```

## Related

- [GET /docs/find](/services/docs-find) ($0.003): Find the AI-ready docs for any library or API: checks the project's docs site (from its npm, PyPI, crates or Go metadata) or any company domain (docs., develope
- [GET /docs/lib](/services/docs-lib) ($0.005): Up-to-date docs for any npm, PyPI, crates or Go library, trimmed for a coding agent's context: finds the project's own llms.txt and docs pages (or the latest re
- [POST /docs/answer](/services/docs-answer) ($0.02): Ask a coding question about any npm, PyPI, crates or Go library and get an answer written only from its current docs (project llms.txt, docs pages or latest REA
- [GET /openapi](/services/openapi) ($0.005): Understand any public API fast: give its OpenAPI/Swagger spec URL, its docs or base URL, or a name from the APIs.guru directory (?api=stripe.com); we find the s
- [GET /library/research](/services/library-research) ($0.10): Premium research report on a library or API for coding agents: reads its current docs for your goal, checks version, safety and repository health, gathers what 
- [GET /package/check](/services/package-check) ($0.005): Should a coding agent install this package?
- [GET /dependency/verdict](/services/dependency-verdict) ($0.03): "Should I use this dependency?" in one call for npm, PyPI, crates or Go: full package safety check (vulnerabilities, malware, typosquats, deprecation, licence, 
- [GET /dependency/report](/services/dependency-report) ($0.08): Premium "should I use this dependency?" report: package safety (vulnerabilities, malware, typosquats, deprecation), GitHub repository health, licence compatibil

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