Project configuration

Annif projects are used to set up backends and configure them with a specific vocabulary and parameters. Projects are defined in a file commonly called projects.cfg. By default, Annif looks for this file in the current directory where it is executed, but you can specify another path using the ANNIF_PROJECTS environment variable or the --projects option after a command.

Here is an example project configuration. The configuration file format follows the INI style and each project is represented as a section, with the identifier of the project as the section name.

[tfidf-en]
name=TF-IDF English
language=en
backend=tfidf
analyzer=snowball(english)
limit=100
vocab=yso-en

A project has the following attributes:

Setting	Description
identifier	An identifier consisting of alphanumeric characters and basic punctuation.
name	A human-friendly name.
language	IETF BCP 47 language code.
backend	The backend (algorithm) that the project uses. See below for details.
analyzer	The analyzer used to pre-process and tokenize text. See below for details.
limit	The maximum number of results (subjects/concepts) to return.
input_limit	The maximum number of the characters of input document to use for making suggestions. With the value 0 (default) the limit is not applied.
vocab	An identifier for the vocabulary used by this project
access	Access level when project is accessed via the REST API. Can be public (default), hidden or private, see below.

Some backends also use additional parameters (tfidf doesn't), but if they are not present in the configuration file, default values are used.

For some commands it is possible to override a parameter set in the configuration file using the --backend-param option; the syntax for this is --backend-param <backend>.<parameter>=<value>.

Backends

For a list of supported backends, see Home.

The ensemble backend provides a way of combining results from multiple backends.

Analyzers

Analyzers are used to pre-process text. For a list of supported analyzers, see Analyzers.

Vocabularies

Most backends require a subject vocabulary. A vocabulary itself doesn't need any configuration, but the project must define an identifier for the vocabulary it uses. All projects with the same vocabulary identifier will share the same vocabulary, so the vocabulary only needs to be loaded (using the loadvoc command) for one of them.

Note that in Annif, vocabularies, like projects, are monolingual. If you load a multilingual SKOS vocabulary for a project, only the labels in the language defined for the project will be loaded.

Access levels

Access levels can be used to restrict which projects are available via the REST API. The default access level is public, meaning that the project is visible in the response for the projects method and can be used for suggesting concepts. The hidden level makes the project invisible, but it can still be accessed if the project ID is known. The private level means that the project is not available at all via the REST API.