Cta

mcp-cta

CTA MCP — Chicago Transit Authority real-time trains ('L') + buses

Part of Pipeworx — an MCP gateway connecting AI agents to 1875+ live data sources. This is an independent, unofficial integration — not affiliated with, endorsed by, or published by the upstream provider.

Tools

Tool	Description
cta_train_arrivals	Real-time Chicago CTA 'L' train arrivals at a station — answers "when is the next train Chicago", next Red Line at Belmont, Blue Line to O'Hare from Clark/Lake. Returns each upcoming train's line color, destination, arrival time and minutes_away, plus approaching / delayed / scheduled-only flags and the platform description. Station accepts a name ("Belmont", "Clark/Lake", "O'Hare") or a 5-digit mapid (e.g. 41320). Example: cta_train_arrivals({ station: "Belmont", route: "Red" })
cta_train_positions	Live Chicago CTA 'L' train positions on one or more lines — where every Red Line, Blue Line, Brown, Green, Orange, Purple, Pink, or Yellow train is right now: lat/lon, heading, next station with ETA, destination, approaching and delayed flags. Answers "where are the Blue Line trains" for the Chicago L. Example: cta_train_positions({ routes: "Red,Blue" })
cta_bus_predictions	Chicago CTA bus tracker arrival predictions at a bus stop — route, destination, predicted minutes until arrival ("DUE" = arriving now), delay flag, and vehicle id. Pass stop_id (the 4-5 digit stop number posted on CTA bus-stop signs), optionally with route. If you only know the stop by name, pass route + find_stop (a street/intersection fragment like "clark & madison") and the stop is looked up for you. Example: cta_bus_predictions({ route: "22", find_stop: "addison" })
cta_bus_positions	Live Chicago CTA bus positions on a route — every vehicle currently running: lat/lon, heading, destination, delayed flag, and distance along the pattern. Answers "where is the 22 Clark bus right now" via the CTA bus tracker. Example: cta_bus_positions({ route: "22" })

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{
  "mcpServers": {
    "cta": {
      "url": "https://gateway.pipeworx.io/cta/mcp"
    }
  }
}

What this endpoint actually serves

tools/list at https://gateway.pipeworx.io/cta/mcp returns the tools in the table above plus the shared Pipeworx meta-tools — ask_pipeworx, discover_tools, search_within, remember/recall and the rest of the gateway-wide set. So the tool count you see is larger than this table: a single-pack endpoint currently lists roughly 30 shared tools alongside the pack's own. The connection's initialize response states its exact scope, and is the authoritative answer for a given day.

This is deliberate, not multiplexing by accident. The meta-tools are what let a scoped connection answer a question this pack does not cover — via ask_pipeworx, which routes across the whole catalog — without you adding a second MCP server. There is currently no way to mount a pack endpoint without them; if the extra schemas cost you more context than the routing is worth, connect to the full gateway once rather than to several pack endpoints.

Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:

{
  "mcpServers": {
    "pipeworx": {
      "url": "https://gateway.pipeworx.io/mcp"
    }
  }
}

Both URLs reach the same gateway and the same 1875+ data sources. The only difference is which pack's tools are listed directly; ask_pipeworx reaches all of them from either one.

No MCP client? Call it over HTTP

curl -X POST https://gateway.pipeworx.io/v1/tools/cta_train_arrivals \
  -H 'Content-Type: application/json' \
  -d '{"station":"Belmont","route":"Red"}'

No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/cta_train_arrivals. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.

Standalone (no gateway account)

This package also runs as a local stdio MCP server — no Pipeworx account, no gateway round-trip:

{
  "mcpServers": {
    "cta": {
      "command": "npx",
      "args": ["-y", "@pipeworx/mcp-cta"]
    }
  }
}

Or run it directly to confirm it starts:

npx -y @pipeworx/mcp-cta

It speaks MCP over stdin/stdout and answers initialize/tools/list/tools/call for only this pack's tools — none of the shared meta-tools the gateway connection above adds. Same source, same tools, no ask_pipeworx routing.

Using with ask_pipeworx

Instead of calling tools directly, you can ask questions in plain English — this works on the pack endpoint above as well as on the full gateway:

ask_pipeworx({ question: "your question about Cta data" })

The gateway picks the right tool and fills the arguments automatically.

More

• Docs and guides
• pipeworx.io

License

MIT