# /jmty/lines

`POST /api/jmty/lines`

Price: 1 credit

List the railway lines Jimoty (jmty.jp) indexes a Japanese prefecture by, with the operator that runs each line and the numeric id the board filters on, and — for a single line — every station on it with its own numeric id. Jimoty is organised around geography first and lets a search be pinned to a whole line or to one station, but it prints those ids nowhere else, so this is the lookup that makes the line_id and station_id filters of jmty/listings/search reachable. Tokyo is indexed by 81 lines across eleven operators, Osaka by 54, a rural prefecture such as Tottori by 7.

## How to use it

List Jimoty railway lines for one prefecture. prefecture is required and accepts the 47 romaji prefecture slugs, but not all — lines are indexed per prefecture. Feed id into the line_id filter of jmty/listings/search. Pass line_id here to get that one line together with its stations, whose ids feed the station_id filter. The same line catalogue serves every section of the board.

## Parameters

- `access-token` (string, required)

## Request body

- `timeout` (integer) — Max scrapping execution timeout (in seconds) (default: 300; min: 20; max: 1500)
- `prefecture` (string, required) — Prefecture whose railway lines to list (one of: "all", "hokkaido", "aomori", "iwate", "miyagi", "akita", "yamagata", "fukushima", "ibaraki", "tochigi", "gunma", "saitama", "chiba", "tokyo", "kanagawa", "niigata", "toyama", "ishikawa", "fukui", "yamanashi", "nagano", "gifu", "shizuoka", "aichi", "mie", "shiga", "kyoto", "osaka", "hyogo", "nara", "wakayama", "tottori", "shimane", "okayama", "hiroshima", "yamaguchi", "tokushima", "kagawa", "ehime", "kochi", "fukuoka", "saga", "nagasaki", "kumamoto", "oita", "miyazaki", "kagoshima", "okinawa"; examples: "tokyo")
- `line_id` (integer, nullable) — Keep only this line and list the stations on it (examples: 11312; >: 0)

## Response

### 200 — Successful Response

- `@type` (string) (default: "JmtyLine")
- `id` (integer, required)
- `name` (string, required)
- `operator` (string, nullable)
- `url` (string, nullable)
- `stations` (array) (default: [])
  - `@type` (string) (default: "JmtyStation")
  - `id` (integer, required)
  - `name` (string, required)
  - `url` (string, nullable)

## Errors

### 422 — Validation Error

The request body did not validate

What to do: Check the fields against this schema. A URN with the wrong prefix is the most common cause.

- `detail` (array)
  - `loc` (array, required)
  - `msg` (string, required)
  - `type` (string, required)
  - `input` (any)
  - `ctx` (object)

### 408

The request ran past its time limit

What to do: Raise `timeout` in the request body, up to the maximum this endpoint documents. Lowering `count` or turning off the `with_*` flags also helps, because less work finishes sooner.

### 412

This prefecture does not index a railway line with this id

What to do: Retrying will not help: either the entity does not exist, or the input points at a different one.

### 429

Too many requests: a rate limit or a usage window is exhausted

What to do: When the response carries an X-Retry-After header, wait that many seconds and retry: the same number is in the body as `detail.retry_after`, and the limit clears once that window passes. The message in the body names the limit that was hit.

### 500

Something broke on our side

What to do: Retrying will not help. If it keeps happening, send us the X-Request-ID from the response headers.

### 529

Rate limit reached, or the endpoint is overloaded

What to do: Wait at least 30 seconds, then retry.

## Response envelope

Success: Array of objects (may be empty if no results)

Error: Error may coexist with partial results if it occurs mid-execution. Check X-Error header and status code.

Every response carries these headers:

- `X-Error` — Error message text (present only on error)
- `X-Request-ID` — Unique request identifier
- `X-Execution-Time` — Execution time in seconds
- `X-Result-Count` — How many records the body carries. 0 means an empty result, which is a normal answer and not by itself an error. A non-zero count can come back together with X-Error when the failure happened partway through — read this header and X-Error independently.
- `X-Total-Available-Results` — How many records exist for this query, when the endpoint can say. On a `dry_run` request this is the answer and the body is empty. It saturates: the endpoint's documented maximum means 'at least that many', any smaller number is exact.
- `X-Warning` — Present when the request body carried keys this endpoint does not document. They were ignored, so any filter you meant to apply through them did not apply. Check the spelling against this schema and retry.
- `X-Retry-After` — Seconds to wait before retrying. Present only on 429.