# /us_hts/chapters/notes

`POST /api/us_hts/chapters/notes`

Price: 20 credits

Get the legal notes governing one US tariff chapter — the chapter notes, subheading notes, Additional U.S. Notes and statistical notes, together with the notes of the section it belongs to

## How to use it

Read this before deciding that a product belongs to a chapter: the notes are what legally include or exclude goods from it, and Additional U.S. Notes carry quota volumes and definitions that exist only in the US schedule and nowhere in the WCO text. A chapter can genuinely have no notes of its own while its section does, and the reverse, so an empty chapter_notes is an answer rather than a miss; the plain-text fields carry any table the source prints inside a note. The section is identified from the chapter number, so no separate section input is needed.

## Parameters

- `access-token` (string, required)

## Request body

- `timeout` (integer) — Max scrapping execution timeout (in seconds) (default: 300; min: 20; max: 1500)
- `chapter` (integer, required) — Tariff chapter number (examples: 9, 61, 98; min: 1; max: 99)

## Response

### 200 — Successful Response

- `@type` (string) (default: "UsHtsChapterNotes")
- `chapter` (integer, required)
- `chapter_title` (string) (default: "")
- `chapter_description` (string) (default: "")
- `chapter_notes` (array) (default: [])
  - `@type` (string) (default: "UsHtsNoteGroup")
  - `note_title` (string, required)
  - `notes` (array) (default: [])
- `chapter_notes_text` (string) (default: "")
- `section_title` (string) (default: "")
- `section_description` (string) (default: "")
- `section_notes` (array) (default: [])
  - `@type` (string) (default: "UsHtsNoteGroup")
  - `note_title` (string, required)
  - `notes` (array) (default: [])
- `section_notes_text` (string) (default: "")
- `subchapter_titles` (array) (default: [])
- `page_references` (array) (default: [])

## 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

The chapter number carries no notes document in the current revision

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.