# SearchMux Delta — Research Change Detection

> SearchMux Delta — Research Change Detection is a paid API for AI agents from searchmux-agent-search.burnzzz0.chatgpt.site, paid per call via x402, $0.029/call, status unknown (last checked 2026-10-11).

Detects what URLs have appeared, disappeared, or persisted in a bounded search result window compared to a previous query snapshot, enabling agents to track research changes over time.

## Facts

- Endpoint: POST https://searchmux-agent-search.burnzzz0.chatgpt.site/api/delta?utm_source=zero.xyz
- Price: $0.029/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/searchmux-delta-research-change-detection-7dedc08f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RljnF4EsPidO6rSqRfxfL

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 searchmux-delta-research-change-detection-7dedc08f -d '<json body>'
```

Example prompt: Check what's changed in search results about 'CRISPR gene editing clinical trials' since my last snapshot — show me any newly appearing URLs, which ones are still there, and which dropped out of the current result window. Pass these prior URLs from last time: [https://example.com/old-result-1, https://example.com/old-result-2].

## When to prefer this

Choose this endpoint when you need to detect changes in search result sets over time rather than just retrieving current results. It is ideal for research monitoring workflows, evidence tracking, competitive intelligence loops, and any agent that needs to know 'what's new since last time' on a topic. Prefer it over a plain search endpoint when you have a prior URL snapshot and want structured diff output rather than a fresh result list.

## Known failure modes

- Missing or malformed prior URL list may cause incorrect delta computation
- Result window is bounded — absence does not guarantee a URL was removed from the web
- Cache hit may return stale delta if called too soon after a prior request
- Degraded mode may return incomplete provider results
- Payment failure via x402 will block the request entirely
- Provider (Exa) downtime may cause degraded or empty results

## How this service works

Five accountless x402 tools for agent search, evidence, research deltas, and passive API discovery readiness.

## Output

A JSON object containing: newly present URLs with titles and snippets ('newResults'), URLs still present from the prior snapshot ('retainedResults'), URLs that were in the prior snapshot but are now absent ('missingFromCurrentWindow'), a 'nextPriorUrls' list to feed into the next delta call, a 'warning' that absence means out-of-window not deleted from the web, cache hit and degraded status flags, provider name, request ID, and generation timestamp.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "limit": {
   "type": "integer",
   "default": 5,
   "maximum": 10,
   "minimum": 1
  },
  "query": {
   "type": "string",
   "pattern": "^\\s*\\S.*\\S\\s*$",
   "maxLength": 500,
   "minLength": 2,
   "description": "Research query; persisted only as a SHA-256 hash."
  },
  "priorUrls": {
   "type": "array",
   "items": {
    "type": "string",
    "format": "uri",
    "pattern": "^https?://",
    "maxLength": 2048
   },
   "maxItems": 25,
   "minItems": 0,
   "description": "Previous result URLs used only for local set comparison; never fetched or persisted.",
   "uniqueItems": true
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "route": "delta",
  "warning": "Missing means absent from this bounded result window, not removed from the web.",
  "cacheHit": false,
  "degraded": false,
  "provider": "exa",
  "requestId": "9e707a98d34e4105a7ef",
  "newResults": [
   {
    "url": "https://example.com/current-result",
    "title": "Current result",
    "snippet": "A source newly present in the bounded result window."
   }
  ],
  "generatedAt": "2026-07-24T00:00:00.000Z",
  "nextPriorUrls": [
   "https://example.com/current-result"
  ],
  "retainedResults": [],
  "missingFromCurrentWindow": [
   "https://example.com/older-result"
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/searchmux-delta-research-change-detection-7dedc08f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from searchmux-agent-search.burnzzz0.chatgpt.site](https://www.zero.xyz/host/searchmux-agent-search.burnzzz0.chatgpt.site/llms.txt)