Using the Indigo API

This guide is for developers who want to use the API to fetch legislative works. We assume that you have a basic understanding of REST APIs and the Akoma Ntoso standard for legislation (acts in particular).


The API relies heavily on Akoma Ntoso FRBR URIs, which are described in the Akoma Ntoso naming convention standard.

Getting Started

The API is a read-only API for listing and fetching published versions of legislative works. Using it, you can:

  • get a list of countries and localities
  • get a list of all works by country and year
  • get a JSON description of a work
  • get Akoma Ntoso XML for a work
  • get a human-friendly HTML version of a work


When we use a URL such as /api/v2/frbr-uri/ in this guide, the frbr-uri part is a full FRBR URI, such as /akn/akn/za/act/1998/84.

Works and Expressions

Two important concepts that are an essential part of the API are works and expressions.

  • A Work is a piece of legislation, such as an act, regulation or by-law. A work may be amended over time and may even have its title changed. A work is uniquely identified by a work FRBR URI which never changes.
  • An Expression is a version of a Work in specific language at a particular point in time. A work can have many expressions, usually one for each official language and amendment. An expression is uniquely identified by its own expression FRBR URI, which is derived from the work’s FRBR URI.

An example of a work is the South African Employment Equity Amendment Act, 2013 (Act 55 of 1998) with unique work FRBR URI /akn/za/act/1998/55. This act has been amended a number of times since it was first passed. Each amended version (also called a point in time) is a unique expression of the work.

The English expression of the work, as it was amended on 17 January 2014, is uniquely identified by the expression FRBR URI /act/1998/55/eng@2014-01-17. You can see that this is built from the work’s URI, with a language code eng and the expression date 2014-01-17 included.


When fetching details from the API, you are always fetching details for a particular expression of the work. The expression will also include information related to the expression’s work, such as the work’s FRBR URI and publication information.

Even if you don’t specific a particular date for the expression, the API will return the latest expression applicable for the date of the request.

Location of the API

The API is available at the /api/v2/ URL of your Indigo installation.


You must authenticate all calls to the API by including your API authentication token in your request. Include in your request an HTTP header called Authorization with a value of Token <your-api-token>. For example:

Authorization: Token 9944b09199c62bcf9418ad846dd0e4bbdfc6ee4b

Content types

Some API calls can return content in multiple formats. You can specify the required content of your request by placing .format at the end of the URL. In most cases the default response type is JSON.

  • .json or Accept: application/json: return JSON
  • .xml or Accept: application/xml: return Akoma Ntoso XML
  • .html or Accept: text/html: return human friendly HTML
  • .epub or Accept: application/epub+zip: return an ePUB (ebook) document
  • .pdf or Accept: application/pdf: return a PDF document
  • .zip or Accept: application/zip: return a ZIP file with the document XML and media attachments


Not all responses support all formats, the documentation will be explicit about what is supported.

Countries and Localities

GET /api/v2/countries.json

This returns a list of the countries and localities that Indigo knows about. It includes links to the APIs for listing works for each country and locality.

Fetching a Work

GET /api/v2/frbr-uri.json

This returns the detail of an expression of a work as a JSON document. For example, this is the description of the English expression of Act 55 of 1998 as at 2014-01-07.

  "url": "",
  "title": "Employment Equity Act, 1998",
  "created_at": "2017-12-23T10:05:55.105543Z",
  "updated_at": "2018-06-07T08:07:51.170250Z",
  "country": "za",
  "locality": null,
  "nature": "act",
  "subtype": null,
  "year": "1998",
  "number": "55",
  "frbr_uri": "/act/1998/55",
  "expression_frbr_uri": "/act/1998/55/eng@2005-10-03",
  "publication_date": "1998-10-19",
  "publication_name": "Government Gazette",
  "publication_number": "19370",
  "expression_date": "2014-01-17",
  "commencement_date": "1999-05-14",
  "assent_date": "1998-10-12",
  "language": "eng",
  "repeal": null,
  "numbered_title": "Act 55 of 1998",
  "amendments": [
      "date": "2014-01-17",
      "amending_title": "Employment Equity Amendment Act, 2013",
      "amending_uri": "/akn/za/act/2013/47"
  "points_in_time": [
      "date": "2014-01-17",
      "expressions": [
          "url": "",
          "language": "eng",
          "expression_frbr_uri": "/act/1998/55/eng@2014-01-17",
          "expression_date": "2014-01-17",
          "title": "Employment Equity Act, 1998"
  "links": [
      "href": "",
      "title": "HTML",
      "rel": "alternate",
      "mediaType": "text/html"
    { "..." }

The fields of the response are described in the table below.

Field Description Type
amendments List of amendments that have been applied to create this expression of the work. See below
as_at_date Date up to which this work has been updated. ISO8601
assent_date Date when the work was assented to. ISO8601
content_url URL of the full content of the work. URL
country ISO 3166-1 alpha-2 country code that this work is applicable to. String
created_at Timestamp of when the work was first created. ISO8601
draft Is this a draft work or is it available in the public API? Boolean
expression_date Date of this expression of the work. ISO8601
commencement_date Date on which this work commences. ISO8601
expression_frbr_uri FRBR URI of this expression of this work. String
frbr_uri FRBR URI for this work. String
id Unique ID of this work. Integer
language Three letter ISO-639-2 language code for this expression of the work. String
links A description of links to other formats of this expression that are available through the API.  
locality The code of the locality within the country. String
nature The nature of this work, normally “act”. String
number Number of this work with its year, or some other unique way of identifying it within the year. String
numbered_title Title of the work using only its numbering system (may be null). String
publication_date Date of original publication of the work. ISO8601
publication_name Name of the publication in which the work was originally published. String
publication_number Number of the publication in which the work was originally published. String
repeal Description of the repeal of this work, if it has been repealed. See below
subtype Subtype code of the work. String
title Short title of the work, in the appropriate language. String
updated_at Timestamp of when the work was last updated. ISO8601
url URL for fetching details of this work. URL
year Year of the work. String


The fields of the amendments property of the response are described below.

Field Description Type
amending_title Title of the amending work String
amending_uri Work FRBR URI of the amending work String
date Date on which the amendment takes place ISO8601

Points in Time

The fields of the points_in_time property of the response are described below.

Field Description Type
date Date of the point-in-time for which expressions are available ISO8601
expressions A list of expressions for this work available at this point in time  
url The API URL to fetch information on the expression URL
language Three-letter language code of the language of the expression String
expression_frbr_uri Unique Expression FRBR URI for this expression String
expression_date Date of this expression ISO8601
title Title of the work, appropriate for the expression in the expression’s language) String

Fetching the Akoma Ntoso for a Work

GET /api/v2/frbr-uri.xml

This returns the Akoma Ntoso XML of an expression of a work.

For example, fetch the most recent applicable English Akoma Ntoso expression of /akn/za/act/1998/55 by calling:

GET /api/v2/akn/za/act/1998/55/eng.xml

Fetching a Work as HTML

GET /api/v2/frbr-uri.html

Fetch the HTML version of a work by specify .html as the format extensions in the URL.

  • Parameter coverpage: should the response contain a generated coverpage? Use 1 for true, anything else for false. Default: 1.
  • Parameter standalone: should the response by a full HTML document, including CSS, that can stand on its own? Use 1 for true, anything else for false. Default: false.
  • Parameter resolver: the fully-qualified URL to use when resolving absolute references to other Akoma Ntoso documents. Use ‘no’ or ‘none’ to disable. Default is to use the Indigo resolver.
  • Parameter media-url: the fully-qualified URL prefix to use when generating links to media, such as images.

For example, fetch the most recent applicable English HTML expression of /akn/za/act/1998/55 by calling:

GET /api/v2/akn/za/act/1998/55/eng.html

Fetching Expressions of a Work

You can fetch specific expressions of a work by including expression-specific information in the requested FRBR URI. The API supports the language and date aspects defined in the Akoma Ntoso naming convention standard.

For example, this request will fetch the HTML of the English expression of Act 55 of 1998, as amended on 2014-01-17:

GET /api/v2/akn/za/act/1998/55/eng@2014-01-17.html

The available expressions of a work are listed in the points_in_time field of the JSON description of the work. Each point in time includes a date and a list of expressions available at that date, one for each available language.

You can use the following date formats to request different expressions of a work.

Date Format Meaning Example Expression FRBR URI
@ Very first expression of a work. /akn/za/act/1998/55/eng@
@YYYY-MM-DD Expression at the specific date. /akn/za/act/1998/55/eng@2014-01-17
:YYYY-MM-DD Most recent expression at or before a date. /akn/za/act/1998/55/eng:2015-01-01
(none) The most recent expression at or before today’s date. Equivalent to using : with today’s date. /akn/za/act/1998/55/eng

The .format part of the FRBR URI is placed after the @YYYY-MM-DD part.


If you use @ to specify a particular date and the API doesn’t have a version at exactly that date, it will return a 404 response. If you need the expression of the work closest to a particular date, use : instead.

Table of Contents

GET /api/v2/frbr-uri/toc.json
  • Content types: JSON

Get a description of the table of contents (TOC) of an act. This includes the chapters, parts, sections and schedules that make up the act, based on the structure captured by the Indigo editor.

Each item in the table of contents has this structure:

  "id": "chapter-1",
  "type": "chapter",
  "num": "1",
  "heading": "Interpretation",
  "title": "Chapter 1 - Interpretation",
  "component": "main",
  "subcomponent": "chapter/1",
  "url": "",
  "children": [ "..." ]

Each of these fields is described in the table below.

Field Description Type
id The unique XML element id of this item. (optional) String
type The Akoma Ntoso element name of this item. String
num The number of this item, such as a chapter, part or section number. (optional) String
heading The heading of this item (optional) String
title A derived, friendly title of this item, taking num and heading into account and providing good defaults if either of those is missing. String
component The component of the Akoma Ntoso document that this item is a part of, such as main for the main document, or schedule1 for the first schedule. String
subcomponent The subcomponent of the component that this item is a part of, such as a chapter. (optional) String
url The API URL for this item, which can be used to fetch XML, HTML and other details of just this part of the document. String
children A possibly-empty array of TOC items that are children of this item. Array

Fetching Parts, Chapters and Sections

You can use the url field from an item in the table of contents to fetch the details of just that item in various forms.

GET /api/v2/frbr-uri/toc-item-uri.format
  • Content types: XML, HTML, PDF, ePUB, ZIP

Using HTML Responses

Indigo transforms Akoma Ntoso XML into HTML5 content that looks best when styled with Indigo Web stylesheets. You can link to the stylesheets provided by that package, or you can pull them into your website.

Listing Works

GET /api/v2/akn/za/
GET /api/v2/akn/za/act/
GET /api/v2/akn/za/act/2007/
  • Content types: JSON, PDF, EPUB, ZIP

These endpoints list the works for a country or year. To list the available works for a country you’ll need the two-letter country code for the country.

The listings include the most recent applicable expressions of each work, in the country’s default language.