XCREENER Query Language · REST API · MCP

Query the Market Like a Database

rsi(14) < 30 and close > d::sma(200) — oversold on the hourly, still in a daily uptrend. XCREENER Query Language (XQL) reads like a query language because it is one: combine RSI, moving averages, breakouts, and multiple timeframes into the exact condition you're looking for, then run it against market data — instantly in the Playground, or over the API.

New to XCREENER? Start with the screener pages — no code, no signup required. This page is for when you want to go further.

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Three endpoints, one query language

Every request reads the raw XQL query text from the request body and requires an API key. /xql/run is all you need to go live — validate and explain are there when you're debugging a query.

POST/xql/validate

Checks your query is well-formed, no data touched. Optional — skip straight to /xql/run.

curl https://api.xcreener.com/xql/validate \
  -H "Authorization: Bearer <your-api-key>" \
  --data-raw 'market = "FOREX"
timeframe = h4

close > highest(high, 20) and volume > avg(volume, 20) * 1.5'
Success — 200
{ "valid": true }
Failure — 400
{
  "valid": false,
  "error": {
    "type": "syntax",
    "message": "Unexpected end of input, expected ')'",
    "position": { "line": 3, "column": 12, "offset": 45 }
  }
}
POST/xql/explain

Returns the data your query needs and a plain description of what it matches. Optional — skip straight to /xql/run.

curl https://api.xcreener.com/xql/explain \
  -H "Authorization: Bearer <your-api-key>" \
  --data-raw 'market = "CRYPTO"
timeframe = h1

rsi(14) < 30 and h4::rsi(14) < 40'
Success — 200
{
  "plan": {
    "market": "CRYPTO",
    "sources": [
      { "timeframe": "h1", "series": ["close"], "minLookback": 15 },
      { "timeframe": "h4", "series": ["close"], "minLookback": 15 }
    ]
  },
  "explanation": "Matches when rsi(14) < 30 and h4::rsi(14) < 40."
}
Failure — 400
{
  "valid": false,
  "error": {
    "type": "syntax",
    "message": "Unknown identifier 'closee', did you mean 'close'?",
    "position": { "line": 3, "column": 1, "offset": 32 }
  }
}
POST/xql/run

Fetches data and runs your query against every instrument in the market/timeframe.

curl https://api.xcreener.com/xql/run \
  -H "Authorization: Bearer <your-api-key>" \
  --data-raw 'market = "CRYPTO"
timeframe = h1
columns = [close, volume]
sort = volume desc
limit = 5

crossover(ema(volume, 10), ema(volume, 30))'
{
  "results": [
    {
      "symbol": "ETHUSDT",
      "columns": { "close": 3421.55, "volume": 84213.4 }
    },
    {
      "symbol": "SOLUSDT",
      "columns": { "close": 142.31, "volume": 512044.2 }
    }
  ]
}

Connect via MCP

The same xql_validate, xql_explain, xql_run, and xql_nl_reference tools as the REST API, exposed over MCP through xcreener-mcp, an open-source local bridge for Claude Desktop, Claude Code, Cursor, Windsurf, and any other stdio MCP client.

Claude Desktop — download & double-click to install
Download xcreener.mcpb
Claude Code
claude mcp add xcreener -e XCREENER_API_KEY=<your-api-key> -- npx -y @xcreener/mcp
Cursor, Windsurf & other stdio clients — via npx
{
  "mcpServers": {
    "xcreener": {
      "command": "npx",
      "args": ["-y", "@xcreener/mcp"],
      "env": {
        "XCREENER_API_KEY": "your-actual-key-here"
      }
    }
  }
}
Source
github.com/xcreener/xcreener-mcp
✓

Claude Code

One CLI command wires up the bridge as a local stdio server, with your API key passed as an environment variable.

✓

Claude Desktop

Download the xcreener.mcpb bundle, then double-click it to install — Desktop asks for your API key in a masked field as part of that same dialog. No JSON to hand-edit, no separate Node install.

✓

Cursor & Windsurf

Run npx @xcreener/mcp locally via the config below (Cursor: ~/.cursor/mcp.json, Windsurf: ~/.codeium/windsurf/mcp_config.json).

✓

Other MCP clients

Any stdio-capable MCP client can run npx @xcreener/mcp the same way, with XCREENER_API_KEY set in its environment.

Human query → XQL

Ask in plain English — the assistant calls the xql_nl_reference tool to look up the phrase-to-XQL mapping, then validates and runs the query for you.

“It's oversold”

rsi(14) < 30

“Volume more than 2x its average”

let avgv = avg(volume, 20)
volume > avgv * 2

“New 52-week high”

close >= w::highest(high, 52)

How it works

Write your query and run it — validate and explain are optional tools for when you're debugging.

Step 1

Write your query

Draft your XQL query for the market and timeframe you care about — try it in the free Playground, no API key needed.

Step 2

Debug it, if you need to

/xql/validate and /xql/explain are optional dev tools — not required once your query works.

Step 3

Run it

/xql/run is the only endpoint you need to go live.

Included with Essential and Plus

API and MCP access both come with the Essential and Plus plans — generate a key from your account once you've upgraded, and every REST endpoint and MCP tool (validate, explain, run) is ready to call. Plus includes a higher daily API request limit for heavier automated use.

Sign up for API access