# MCP Registry Change Delta Feed

> MCP Registry Change Delta Feed is a paid API for AI agents from fresh-feeds.foomworks.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Returns the incremental delta of the MCP registry since the last daily baseline, listing added, removed, and changed (score/status) servers.

## Facts

- Endpoint: GET https://fresh-feeds.foomworks.workers.dev/feeds/mcp-registry/changes
- 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/mcp-registry-change-delta-feed-63802003
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UBCX9yWcYy4_CMVw4UEqd

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 mcp-registry-change-delta-feed-63802003
```

Example prompt: What's changed in the MCP registry since yesterday's baseline — any servers added, removed, or with updated quality scores?

## When to prefer this

Prefer this endpoint over the full MCP registry snapshot when you are a repeat caller who already has a recent snapshot and only needs incremental updates. It is significantly cheaper (same $0.02 price but far less data to process) and faster than re-fetching the full catalog. Use the full snapshot endpoint for cold starts or when you need guaranteed consistency.

## Known failure modes

- Baseline not yet established for the day — delta may be empty or return an error if baseline is pending
- Payment failure via x402 — 402 response if USDC payment is not completed before the request
- Stale or unavailable upstream registry — delta may reflect outdated source data
- Empty delta if no changes occurred since the last baseline

## How this service works

Delta of the MCP registry since a daily baseline: added, removed, and changed (score/status) servers — the cheap habit endpoint for repeat callers.

## Output

A structured delta object listing MCP servers added since the daily baseline, servers that were removed, and servers whose quality score or status changed — enabling efficient incremental sync without re-fetching the full registry snapshot.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mcp-registry-change-delta-feed-63802003/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fresh-feeds.foomworks.workers.dev](https://www.zero.xyz/host/fresh-feeds.foomworks.workers.dev/llms.txt)