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Welcome to the documentation of Dicio, the free software voice assistant for Android. This website contains information on how to use specific features of Dicio, as well as how to contribute to its development, and how to do maintainer tasks.

Project structure

Main repository with Android App and skill interfaces: dicio-android
Domanin specific language and parser for skill sentences: dicio-sentences-compiler
Multilanguage number parsing and formatting library: dicio-numbers
Testing workbench to evaluate language matching algorithms: dicio-evaluation

Editing this wiki

You can find the source code of this website here. If you notice a mistake, or want to add a page with useful information, feel free to open a pull request. The policy for merging documentation PRs is to quickly take a look to ensure there are no major mistakes, but to otherwise trust the author and merge the pull request as soon as possible. This is to incentivize writing or amending documentation (just like on Wikipedia you can direclty edit pages).

Translating to a new language

Unlike other Android projects, Dicio’s translatable files are not only the plain strings listed under app/src/main/res/values/strings.xml, but there are additional files that define which sentences the skills should recognize.

Plain strings used in the UI

Translate the strings used inside the app via Weblate.
If your language is not already there, add it with tool -> start new translation.

Sentences for recognizing user intent

Translate the sentences used by Dicio to identify a user’s request and to feed it to the correct skill. At the moment this requires manually modifying files in the source code repository. Hopefully in the future a custom translation system, similar to Weblate, will be used for sentences too.

Fork the main repository and clone the fork using git. If you don’t know what that means, this and this guide can help. Feel free to reach out for help if you get stuck.
Navigate to app/src/main/sentences/ inside the repository.
If it does not exist already, create a subfolder with the 2- or 3-letter name of your language (in particular, any ISO-639-compliant language ID is supported).
For each of the skills that have not been translated to your language yet ¹, copy the corresponding English file from en/SKILLNAME.yml to your language’s folder. If you wish to translate everything, then at the end of this process the list of files under the en/ folder should be the same as those in your language’s folder.
Open each of the untranslated skill YAML files and translate the English content. Feel free to add/remove sentences if their translation does not fit into your language and remember those sentences need to identify as best as possible what the user said.
Do NOT change the name of the copied files, the IDs of the sentences (i.e. the sentence_id: before each list of sentences) or the IDs of the capturing groups (i.e. the .ID. construct).
To learn about the Dicio sentences language syntax, please refer to the documentation and the example in dicio-sentences-compiler.

Finally adding the language to the app

Once both the Weblate and the sentences translations are ready, add the new language to the app’s language selector. This requires modifying two files. In the following instructions $iso-language-id$ , $ISO_LANGUAGE_ID$ and $Language name$ are placeholders you should fill in, e.g. en-in, EN_IN and English (India).
1. in app/src/main/proto/language.proto add a new entry to the Language enum like so: LANGUAGE_$ISO_LANGUAGE_ID$ = $increasing number$; // $Language name$. Use the previous highest number in the enum incremented by 1 as $increasing number$ . The position of the newly added item should make it so that the items are sorted by their language name.
2. in app/src/main/kotlin/org/stypox/dicio/settings/Definitions.kt add a new item to languageSetting.possibleValues like so: ListSetting.Value(Language.LANGUAGE_$ISO_LANGUAGE_ID$, "$Language name$"),. The position of the newly added item should make it so that the items are sorted by their language name.
Then update the app descriptions so that people know that the language you are adding is supported. The files you should edit are README.md and fastlane/metadata/android/en-US/full_description.txt (the English description for F-Droid).
Open a pull request containing both the translated sentences files, the language selector addition and the app descriptions updates. You may want to take a look at the pull request that added German, #19, and if you need help don’t hesitate to ask :-)

if you just created the subfolder in the previous step, then none of the skill had been translated before ↩

Adding a new skill

A skill is a component that enables the assistant to understand some specific queries from the user and act accordingly. While reading the following instructions, keep in mind that the javadoc of the methods being implemented serves as documentation, and that the code of the already implemented skills can be used as reference.

Important

Whenever you see $skill_id$ and $SkillId$ , replace them with the computer readable name of the skill you want to add, in snake_case and PascalCase, e.g. weather or Weather.

1. Reference sentences

The new skill most likely needs to interpret user input. The Dicio framework provides a standard way to define how to efficiently match user input and extract information from it, in the form of translatable reference sentences stored in YAML files. Note that for some specific cases the standard recognizer might not be wanted, in which case you can skip this section, and in section 3 extend Skill<> and implement Skill.score() manually, instead of extending StandardRecognizerSkill<>.

Edit the app/src/main/sentences/skill_definitions.yml file and add a definition for the new skill:

  # The unique ID of the skill.
- id: $skill_id$
  # `SPECIFICITY` can be `high`, `medium` or `low`.
  # It should be chosen wisely: for example, a section that matches queries
  # about phone calls is very specific, while one that matches every question
  # about famous people has a lower specificity.
  specificity: SPECIFICITY
  # A list of definitions for the types of sentences this skill can interpret.
  # Can contain multiple sentences, e.g. the timer skill has the
  # "set", "cancel" and "query" sentences.
  sentences:
      # An ID for the sentence, must be unique amongst this skill's sentences.
    - id: SENTENCE_1_ID
      # (optional) If this sentence has some capturing groups, their IDs and
      # types must be listed here.
      captures:
          # An ID for the capturing group, must be unique amongst this
          # sentence's capturing groups
        - id: CAPTURING_GROUP_1_ID
          # Currently only string capturing groups are supported, but in
          # the future "number", "duration" and "date" will also be possible.
          # For the moment use "string" and then manually parse the string to
          # number, duration or date using dicio-numbers.
          type: string

Create a file named $skill_id$.yml (e.g. weather.yml) under app/src/main/sentences/en/: it will contain the sentences the skill should recognize.

For each of the sentence definitions in skill_definitions.yml, write the id of each sentence type followed by : and a list of sentences:

SENTENCE_1_ID:
  - a<n?> sentence|phrase? alternative # ...
  - another sentence|phrase? alternative with .CAPTURING_GROUP_1_ID. # ...
  # ...
# SENTENCE_2_ID: ... in case you have multiple sentence types

Write the reference sentences according to the dicio-sentences-language’s syntax.
Try to build the app: if it succeeds you did everything right, otherwise you will get errors pointing to syntax errors in the .yml files.

Here is an example of the weather skill definition in skill_definitions.yml:

- id: weather
  specificity: high
  sentences:
    - id: current
      captures:
        - id: where
          type: string

And these are the example contents of app/src/main/sentences/en/weather.yml:

current:
  - (what is|s)|whats the weather like? (in|on .where.)?
  - weather (in|on? .where.)?
  - how is it outside

2. Subpackage

Create a subpackage that will contain all of the classes you are about to add: org.stypox.dicio.skills.SKILLID (e.g. org.stypox.dicio.skills.weather).

3. The Skill class

Create a class named $SkillId$Skill (e.g. WeatherSkill): it will contain the code that interprets user input (i.e. the score() function) and that processes it to generate output (i.e. the generateOutput() function). The next few points assume that you want to use the standard recognizer with the skill definition and sentences you created in step 1. In that case score() is actually already implemented and you don’t need to provide an implementation yourself.

Have the $SkillId$Skill class implement StandardRecognizerSkill<$SkillId$>. You can import the $SkillId$ class with import org.stypox.dicio.sentences.Sentences.$SkillId$. The Sentences.$SkillId$ sealed class is generated based on skill_definitions.yml, and contains one subclass for each of the defined sentence types.
The constructor of Skill takes SkillInfo (see step 5), and moreover the constructor of StandardRecognizerSkill takes StandardRecognizerData<$SkillId$> (the data generated from the sentences, see step 5). You should expose these two parameters in $SkillId$Skill’s constructor, too.
Implement the following function: override suspend fun generateOutput(ctx: SkillContext, inputData: $SkillId$): SkillOutput. inputData is, again, an instance of Sentences.$SkillId$ corresponding to the matched sentence type, and its fields contain type-safe information about the data captured in capturing groups (if any).
Any code making network requests or heavy calculations should be put in generateOutput (which is a suspend function for this exact purpose). The returned SkillOutput should contain all of the data needed to actually show the output, i.e. it shouldn’t do any more network requests or calculations (unless it’s an interactive widget and the user presses some button, but that’s not too relevant for the matter at hand).

This is a stub implementation of the WeatherSkill:

package org.stypox.dicio.skills.weather
import org.stypox.dicio.sentences.Sentences.Weather
// ...
class WeatherSkill(correspondingSkillInfo: SkillInfo, data: StandardRecognizerData<Weather>) :
    StandardRecognizerSkill<Weather>(correspondingSkillInfo, data) {
    override suspend fun generateOutput(ctx: SkillContext, inputData: Weather): SkillOutput {
      return // ...
    }
}

4. SkillOutput

Create a class named $SkillId$Output (e.g. WeatherOutput): it will contain the code that creates a Jetpack Compose UI and provides speech output.

The class should be constructed by Skill.generateOutput() with all of the data needed to display/speak output, and is meant to be serializable (so in most cases it is a data class). In some cases it might make sense to have multiple types of output (e.g. the weather has Success and Failed output types): in that case you can create a sealed interface and have both output types extend it.
getSpeechOutput() returns a localized string that will be spoken via the configured Text To Speech service.
@Composable GraphicalOutput() builds the UI that will be shown in a box on the home screen. The UI can be interactive and can act as a widget: for example the timer skill shows the ongoing countdown.
[Optional] getNextSkills() returns a list of skills that could continue the current conversation. If this list is non-empty, the next time the user asks something to the assistant, these skills will be considered before all other skills, and if any of these skills understands the user input well enough, the conversation continues. For example, if the user says “Call Mom”, the assistant may answer with “Should I call mom?” and this method would return a skill that can understand a yes/no response.

This is a stub implementation of WeatherOutput:

data class WeatherOutput(
    val city: String,
    val description: String,
    // ...
) : WeatherOutput {
    override fun getSpeechOutput(ctx: SkillContext): String = ctx.getString(
        R.string.skill_weather_in_city_there_is_description, city, description
    )

    @Composable
    override fun GraphicalOutput(ctx: SkillContext) {
        // Jetpack Compose UI
    }
}

5. SkillInfo

Create an object named $SkillId$Info (e.g. WeatherInfo) overriding SkillInfo: it will contain all of the information needed to manage your skill.

This is not a class, but an object, because it makes no sense to instantiate it multiple times.
Call the SkillInfo constructor with the "$skill_id$" string.
Provide sensible values for name(), sentenceExample() and icon().
Override the isAvailable() method and return whether the skill can be used under the circumstances the user is in (e.g. check whether the recognizer sentences are translated into the user language with Sentences.$SkillId$[ctx.sentencesLanguage] != null (see step 1 and step 5.5) or check whether ctx.parserFormatter != null, if your skill uses number parsing and formatting).
Override the build() method so that it returns an instance of $SkillId$Skill with $SkillId$Info as correspondingSkillInfo and, if the skill uses standard recognizer sentences (see step 1), with Sentences.$SkillId$[ctx.sentencesLanguage] as data.
[Optional] If your skill wants to present some preferences to the user, it has to do so by overriding the renderSettings value (which by default returns null to indicate there are no preferences).

The ctx: SkillContext object, that appears here and there in the implementation, allows accessing the Android context, the number parser/formatter and other resources and services, similarly to Android’s context.
The names used for things (files, classes, packages, sections, etc.) are not mandatory, but they help avoiding confusion, so try to stick to them.
When committing changes about a skill, prefix the commit message with “[$SkillId$]”, e.g. “[Weather] Fix crash”.
If you have any question, don’t hesitate to ask. 😃

Dicio developer documentation