Trein extended

Query Dutch Railways (NS) for TRAIN travel only - train departures, time-based trip planning (depart-at/arrive-by), disruptions, and station search via the trein CLI. NOT for car, bus, or other transport.

Security Scan

The skill is internally consistent: it wraps the 'trein' CLI to call the NS API and only requests the trein binary and an NS_API_KEY, which match the stated purpose.

Purpose & Capability

The name/description, required binary (trein), declared install options (npm package and GitHub release binaries), and required env var (NS_API_KEY) all align with a CLI that queries the Dutch Railways API for train information.

Instruction Scope

SKILL.md instructs the agent to run the trein CLI commands, set NS_API_KEY or a local config file, verify train-only intent, and ask users for ambiguous input (e.g., current location). It does not instruct reading unrelated files, accessing other credentials, or exfiltrating data to third parties.

Install Mechanism

Install options are npm (trein package) and direct downloads from GitHub Releases (official project URL). These are expected for a CLI tool; npm packages and 'latest' release downloads are mutable and should be reviewed before installing, but the sources are plausible and from a known release host (GitHub).

Credentials

Only NS_API_KEY is required and is explicitly documented as necessary to call the NS API; no unrelated secrets, system config paths, or additional credentials are requested.

Persistence & Privilege

The skill does not request always:true, does not modify other skills, and has no unusual persistence requirements. Agent autonomous invocation is the platform default and not uniquely elevated here.

Assessment

This skill appears to do what it says: it runs the trein CLI and uses an NS_API_KEY to query the Dutch Railways API. Before installing: (1) verify the npm package name and the GitHub repository (ensure they match and look legitimate); (2) prefer installing a specific release (or verify checksums) rather than blindly using 'latest' downloads; (3) be cautious when running npm -g installs (they alter your system PATH); (4) keep your NS_API_KEY secret, store it in the config file or environment as documented, and rotate it if you suspect misuse; and (5) if you do not want the agent to call the skill autonomously, disable autonomous invocation in your agent settings. If you want higher assurance, inspect the upstream repository or package contents before installing.

trein - Dutch Railways CLI

A CLI for the NS (Dutch Railways) API with real-time train departures, train trip planning, disruptions, and station search.

Install

npm (recommended):

npm i -g trein

Or download a standalone binary from GitHub Releases.

Setup

Get an API key from https://apiportal.ns.nl/ and set it:

export NS_API_KEY="your-api-key"

Or create ~/.config/trein/trein.config.json:

{ "apiKey": "your-api-key" }

Commands

Departures

trein departures "Amsterdam Centraal"
trein d amsterdam
trein d amsterdam --json  # structured output

Trip Planning

trein trip "Utrecht" "Den Haag Centraal"
trein t utrecht denhaag --json
trein t amsterdam rotterdam --via utrecht  # route via specific station
trein t hoofddorp "den haag" --arrive-by 09:30 --json  # arrive by 09:30 TODAY
trein t hoofddorp "den haag" --depart-at 09:00 --json  # depart at 09:00 TODAY
trein t utrecht amsterdam --date 2026-02-05 --depart-at 14:30 --json  # specific FUTURE date and time

Disruptions

trein disruptions
trein disruptions --json

Station Search

trein stations rotterdam
trein s rotterdam --json

Aliases (shortcuts)

trein alias set home "Amsterdam Centraal"
trein alias set work "Rotterdam Centraal"
trein alias list
trein d home  # uses alias

When to Use This Skill

This skill should be used when users ask about TRAIN TRAVEL in the Netherlands:

• "When does the next train to [station] leave?"
• "How do I get from [A] to [B] by train?"
• "I need to be in [station] at [time], which train should I take?"
• "Are there any train disruptions?"
• "What time should I leave to arrive by train at [time]?"
• "What's the train station code for [name]?"
• "Which platform does the train to [station] leave from?"
• "How long does it take to travel by train from [A] to [B]?"

Command Selection Guide

First: Confirm the user wants TRAIN travel. If they want car/bus/other transport, do NOT use this skill.

Then select the appropriate command:

• User wants real-time train departures from ONE station → use departures
• User wants to travel from A to B by train → use trip
• User mentions a specific arrival/departure time for train → use trip with --arrive-by or --depart-at
• User asks about train delays or disruptions → use disruptions
• User gives partial train station name → use stations first to resolve
• User mentions future date for train travel → use trip with --date

JSON Output Examples

Trip Planning Response

{
  "trips": [{
    "departure": "08:05",
    "arrival": "08:35",
    "duration": "30 min",
    "transfers": 0,
    "status": "ON_TIME",
    "legs": [{
      "from": "Schiphol Airport",
      "to": "Den Haag Centraal",
      "trainType": "IC",
      "platform": "5"
    }]
  }]
}

Departures Response

{
  "departures": [{
    "time": "14:23",
    "delay": "0 min",
    "destination": "Amsterdam Centraal",
    "platform": "3",
    "trainType": "IC"
  }]
}

Disruptions Response

{
  "disruptions": [{
    "title": "Werkzaamheden Amsterdam-Utrecht",
    "type": "MAINTENANCE",
    "routes": ["Amsterdam Centraal", "Utrecht Centraal"],
    "active": true,
    "expectedEnd": "2026-02-05 23:59"
  }]
}

Best Practices for AI Agents

1. VERIFY train travel intent - Only use this skill if user explicitly wants train travel, not car/bus/other transport
2. Always use --json for machine-readable output
3. Validate station names first if user input is ambiguous using stations command
4. Use fuzzy matching - don't require exact station names from users
5. Quote station names containing spaces (e.g., "Den Haag Centraal") to prevent argument parsing errors
6. Check for errors in JSON response before presenting results to user
7. Interpret times in 24-hour format (HH:mm)
8. Default to current date - omit --date flag for today's travel; only add --date for future dates
9. Handle Dutch station names - many contain special characters or multiple words
10. Parse JSON carefully - some fields may be null or missing depending on circumstances

Common Workflows

Example 1: "I need to be in Amsterdam at 9:30"

1. Determine current location (ask user if unclear)
2. Check if user means today or a future date
3. Run: trein t hoofddorp amsterdam --arrive-by 09:30 --json (today) OR: trein t hoofddorp amsterdam --date 2026-02-05 --arrive-by 09:30 --json (future date)
4. Parse JSON and present earliest suitable option with departure time

Example 2: "When does the next train to Rotterdam leave?"

1. Determine current location
2. Run: trein d <current-station> --json
3. Filter results for trains going to Rotterdam
4. Present next departure with platform and time

Example 3: "Plan my trip tomorrow at 2pm from Utrecht to Den Haag"

1. Run: trein t utrecht "den haag" --date 2026-02-04 --depart-at 14:00 --json
2. Parse response and present journey options with transfers and duration

Example 4: "Are there delays on my usual route?"

1. First get the trip: trein t amsterdam utrecht --json
2. Then check disruptions: trein disruptions --json
3. Cross-reference routes and inform user of relevant disruptions

Common Errors & Solutions

• "Station not found" → Use trein stations <query> --json to find correct name
• "API key missing" → Verify NS_API_KEY environment variable is set
• Empty results → Check if date/time is in the past
• "No trips found" → Try without --via, route may not be possible via that station

Tips

• Use --json flag for all commands to get structured output for parsing
• Station names support fuzzy matching (e.g., "adam" -> "Amsterdam Centraal")
• Aliases are stored in the config file and can be used in place of station names
• Use --via with trip planning to specify a specific route through an intermediate station
• Use --depart-at HH:mm to plan trips departing at a specific time (defaults to TODAY)
• Use --arrive-by HH:mm to plan trips arriving before a specific time (defaults to TODAY)
• --date YYYY-MM-DD is OPTIONAL - only needed for future dates (omit for today)