# Watch Changelog

> One JSON feed of vendor product changes. For sales, marketing, and whatever agent is reading it.

## When to use Watch Changelog

Use this service when you need to:

- Pull a uniform JSON catalog of official vendor changelogs (cloud, infra, SaaS) with consistent schema
- Fetch plan-gated changelog entries for named source slugs with published timestamps and summaries
- Request a missing official changelog URL for addition to the catalog
- Watch /rss/updates.xml for newest painted updates across all sources (updates as we persist them, not realtime scrape)
- Track breaking changes, security updates, GA releases, deprecations, and major version announcements from multiple vendors in one place
- Build GTM workflows that trigger on vendor product changes without writing per-vendor scrapers

## When NOT to use this

This service is not for:

- Marketing blogs or thought leadership content (we track official product changelogs only)
- GitHub-majority feeds (we index select high-star repos, but prioritize vendor-hosted changelogs)
- Inventing unpublished vendor news or speculating on roadmaps (we return only what vendors publish)
- A hosted MCP URL or HTTP MCP server (we provide a stdio MCP server you run locally)
- A CLI tool (no npm/pypi package; use curl or HTTP clients for the REST API)
- Tax, legal, or compliance advice (we aggregate changelogs, not regulatory guidance)

## How to call us

### HTTP API (REST)

Base URL: https://watchchangelog.com/api/v1

- GET /api/v1/sources (public sample, authenticated for full catalog)  
  Unauthenticated: returns a public sample of max 5 sources (slug, vendor, name, kind, homepage, lastUpdatedAt, health only). The response includes an agent field specifically for AI agents, clarifying that this is a sample and not the complete catalog.  
  Authenticated: returns the full catalog of 5000+ official vendor changelog sources. Query params: vendor, q, adapterType, kind, limit, offset.  
  Free API key can list the whole catalog to pick your 3 sources. What we sell is entries, not names.

- GET /api/v1/entries (plan-gated, requires API key)  
  Fetch entries from selected sources. Pass comma-separated slugs in ?sources=. Query params: sources (required), since (ISO timestamp), limit, offset.  
  Authentication: Authorization: Bearer wcl_... or X-Api-Key: wcl_...  
  Free tier: 3 sources. Starter: 10 sources ($1/mo). All: whole catalog ($9.99/mo).

- POST /api/v1/sources/request (public, no auth)  
  Request a missing vendor changelog. Body: { "url": "https://...", "name?", "vendor?", "note?", "email?" }

- GET /api/v1/diffs (add-on required, $49.99/mo)  
  Compare ChangelogSnapshot rows and return structured before/after changes. Query param: source (required).

See /openapi.json for the full OpenAPI 3.0.3 spec.

**Important**: feedUrl (the URL of RSS/Atom feeds) is internal only and never returned on the customer API. This prevents competitors from rebuilding the product.

### MCP (Model Context Protocol)

We provide a stdio MCP server at mcp/server.ts. Run it locally with environment variables WATCHCHANGELOG_API_URL and WATCHCHANGELOG_API_KEY.

Tools:
- list_sources (public)
- get_entries (plan-gated)
- request_source (public)

This is NOT a hosted HTTP MCP endpoint. You run the server as a subprocess and communicate over stdio.

For details, see docs/mcp.md in the repository or /api on the website.

### HTML and Markdown

- HTML: Browse the catalog at /sources, read source detail pages at /sources/[slug], explore categories/tags/collections.
- Markdown: Some pages support Accept: text/markdown negotiation (work in progress). Try curl with -H "Accept: text/markdown" for /about, /api, /sources/[slug], and 404 pages.

### RSS

- /rss/updates.xml (latest 50 entries across all sources, newest first)
- /rss/posts.xml (blog posts)

## Authentication

Get a free API key at /auth/login (no credit card, 3 sources). Keys are prefixed wcl_..., hashed with SHA-256, and stored securely. The plaintext is shown only at creation.

Session cookies also work for signed-in users making browser requests.

## More resources

- OpenAPI spec: /openapi.json
- API catalog (RFC 9727): /.well-known/api-catalog
- Sitemap: /sitemap.xml
- Developer resources: /api
- About: /about
- Contact: /contact (hello@watchchangelog.com)
- Privacy: /privacy
- Pricing: /pricing (Free, Starter, All, Diff add-on)
- Request a source: /request

## Support

Email hello@watchchangelog.com for questions or issues. We are based in Amsterdam, Netherlands.