# Concordance Full-Text Search

> Concordance Full-Text Search is a paid API for AI agents from concordancehq.duckdns.org, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-16).

Searches across 18 independent real-time data sources (news, SEC filings, court opinions, academic papers, economic indicators, stock quotes, trade data, government records) and returns cited results with source attribution

## Facts

- Endpoint: POST https://concordancehq.duckdns.org/tools/search
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/concordance-full-text-search-2ec19201
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_b8OEs2YcJzdnw9G5asb-O

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 concordance-full-text-search-2ec19201 -d '<json body>'
```

Example prompt: Search Concordance for everything about Nvidia's AI chip export restrictions — pull results from news, SEC filings, and government records so I can see how different sources are covering it.

## When to prefer this

Choose this endpoint when you need multi-source corroboration of a topic — especially when you want news, regulatory filings, legal opinions, and government records searched in a single call with real source citations. Prefer it over single-source news APIs when cross-domain coverage matters, or when you need to know whether a topic appears in SEC filings or court records alongside press coverage. Not ideal for real-time live data (results are refreshed on a schedule) or for deep time-series analysis (use the sibling /series endpoint for that).

## Known failure modes

- No results found for highly specific or obscure queries
- Stale data if a source category has not refreshed recently — check /catalog for freshness timestamps
- Ambiguous query terms may surface unrelated results across broad source categories
- Rate limit or payment failure if the $0.01 USDC x402 payment is not properly submitted
- Source unavailability if one of the 18 upstream feeds is temporarily down at crawl time

## How this service works

Full-text search across every aggregated data source in one call: news, SEC filings, court opinions, academic papers, government records, and developer discussions. One query surfaces everything concordant across independently-sourced, citable results -- not a single-source wrapper. Optional source/category/since filters.

## Output

Returns a JSON object with a count of matches and an array of results, each containing the source URL, title, source identifier (e.g. 'gdelt'), a content snippet, a category label (e.g. 'news_events'), metadata including domain, and a published_at timestamp — all citing the real originating source.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "limit": {
   "type": "integer"
  },
  "query": {
   "type": "string"
  },
  "since": {
   "type": "string"
  },
  "source": {
   "type": "string"
  },
  "category": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "count": 1,
  "results": [
   {
    "url": "https://example.com/article",
    "title": "Central bank signals rate cut",
    "source": "gdelt",
    "content": "Central bank signals rate cut",
    "category": "news_events",
    "metadata": {
     "domain": "example.com"
    },
    "published_at": "2026-07-19T18:30:00+00:00"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/concordance-full-text-search-2ec19201/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from concordancehq.duckdns.org](https://www.zero.xyz/host/concordancehq.duckdns.org/llms.txt)