# /wcohs/nomenclature/search

`POST /api/wcohs/nomenclature/search`

Price: 20 credits

Search the WCO Harmonized System nomenclature — by free text, by code level, or inside the legal notes, Explanatory Notes, Classification Opinions, INN names and CAS registry numbers

## How to use it

Use this to find an HS code from a product name, a chemical identifier or a phrase in the legal text, then read the node itself with wcohs/nomenclature. Two fields have no equivalent anywhere else: cas takes a CAS registry number and inn an International Nonproprietary Name, both returning the headings that cover the substance. Searching explanatorynotes or classificationopinion tells you which codes the WCO discusses in those works, and returns the surrounding excerpt, but not the full text of the note. Each result carries path, the section-to-subheading chain, so a bare code fragment is enough to place a hit in the tree; description is filled only where the source attaches its own wording to a hit.

## Parameters

- `access-token` (string, required)

## Request body

- `timeout` (integer) — Max scrapping execution timeout (in seconds) (default: 300; min: 20; max: 1500)
- `query` (string, required) — Text to search, or the code when field selects section, chapter, heading or subheading (examples: "coffee", "09", "50-78-2"; minLength: 1)
- `field` (string) — Which part of the nomenclature to search — all fields, a code level, the legal notes, the Explanatory Notes, the Classification Opinions, the nomenclature text, an INN name or a CAS registry number (default: "all"; one of: "all", "section", "chapter", "heading", "subheading", "legalnotes", "explanatorynotes", "classificationopinion", "hsnomenclature", "inn", "cas")
- `match` (string) — How the text is matched — near for a loose match, exact for the quoted phrase, begins for a prefix; ignored when field selects a code level (default: "near"; one of: "near", "exact", "begins")
- `edition` (string) — Harmonized System edition to search (default: "2022"; one of: "2022", "2017", "2012", "2007", "2002")
- `language` (string) — Language of the nomenclature text being searched (default: "en"; one of: "en", "fr", "es", "it")
- `latest_only` (boolean) — Keep only nodes changed in the latest update of the chosen edition (default: false)
- `count` (integer, required) — Number of nomenclature nodes to return (min: 1)

## Response

### 200 — Successful Response

- `@type` (string) (default: "WcohsSearchResult")
- `internal_code` (string, required)
- `hs_code` (string) (default: "")
- `node_id` (string) (default: "")
- `level` (string) (default: "")
- `dash_level` (integer) (default: 0)
- `description` (string) (default: "")
- `path` (array) (default: [])
- `url` (string) (default: "")
- `matches` (array) (default: [])
  - `@type` (string) (default: "WcohsSearchMatch")
  - `field_label` (string) (default: "")
  - `excerpt` (string, required)

## 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 entity was not found, or a precondition failed

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.