# transit402.dev Subway Service Alerts

> transit402.dev Subway Service Alerts is a paid API for AI agents from transit402.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Returns active subway service alerts filtered by line, including direction, severity, and estimated delay minutes

## Facts

- Endpoint: POST https://transit402.dev/subway/alerts
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/transit402-dev-subway-service-alerts-47e58f5d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Dyvrfw7VLM0h_plJEPERc

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 transit402-dev-subway-service-alerts-47e58f5d -d '<json body>'
```

Example prompt: Are there any active service alerts on the L or G trains right now? Show me up to 10 alerts with their severity and estimated delays.

## When to prefer this

Use this endpoint when you need real-time, structured subway alert data including delay duration and severity for one or more specific lines, especially in an agentic workflow that needs to advise commuters or route around disruptions. Prefer over generic transit APIs when you need delay minutes and directional context in a single call.

## Known failure modes

- Invalid line identifier returns empty results or validation error
- limit value outside 1–50 range returns a 400 error
- No active alerts returns an empty array
- Service unavailable or data feed outage returns a 5xx error
- Payment not included or insufficient returns a 402 error

## How this service works

Active subway service alerts with direction, severity, and estimated delay minutes

## Output

A list of active subway service alert objects, each containing the affected line(s), direction (uptown/downtown/both), severity level, and estimated delay in minutes — up to the requested limit (default 20, max 50).

## Example request

```json
{
 "limit": 10,
 "lines": [
  "L",
  "G"
 ]
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "limit": {
   "type": "integer",
   "default": 20,
   "maximum": 50,
   "minimum": 1,
   "description": "Optional maximum number of alerts to return (1–50, default 20)."
  },
  "lines": {
   "type": "array",
   "items": {
    "type": "string"
   },
   "maxItems": 26,
   "description": "Optional list of subway line letters/numbers to filter by (e.g. [\"L\", \"G\"]). Omit or pass an empty array to get all currently active alerts. GET clients may pass a comma-separated string."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {}
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/transit402-dev-subway-service-alerts-47e58f5d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from transit402.dev](https://www.zero.xyz/host/transit402.dev/llms.txt)