Context and consent

Your app learns about a learner only through context slices. Each slice is a small record with fixed fields. Your manifest lists the slices it asks for, the learner agrees to each one when they install your app, and Lingara sends a slice only while both still hold.

The slices

Slice	Field	What it holds
`languages`	`source_lang`	The language the learner studies from, as a language tag such as `en`.
	`target_lang`	The language they are learning.
	`level`	Their level in it, from 1 to 9, when they have set one.
`plan_summary`	`plan_id`	The id of their latest lesson plan, which tells one plan from another. Your app cannot fetch the plan with it, because your app’s token reads your own account, not the learner’s.
	`title`	The plan’s generated title, at most 120 characters, when it has one.
	`target_lang`	The language the plan teaches.
	`set_count`	How many sets the plan has, at most 200.
	`sets_completed`	How many of those sets the learner has finished.
`review_due`	`due`	How many flashcards are due now, at most 100000.
	`learned`	How many words they have learned, at most 100000.
`tutor_topic`	`topic`	What their latest tutor chat is about, from 1 to 120 characters. It comes from a plan’s title or the screen they are on, never from their own words.

What no slice carries

No slice carries an email address, a name, a user id or anything the learner typed. Your app learns who the learner is from the request’s subject, a stable value that is different for every app. Your app’s token reads your own account, never the learner’s, so the slices are all your app knows about them.

The learner agrees to each slice when they install your app. To change what they agreed to, they uninstall your app and install it again.
If you edit your manifest to ask for fewer slices, the ones you dropped stop at once.
If you edit it to ask for more, the new slices reach no learner until they reinstall.
Lingara checks consent again on every request, and drops any slice the learner did not agree to or your manifest no longer asks for. A slice that does not fit its record is dropped too, never the whole request.

The sample below builds its line from the slices it was given and calls no API.

TypeScriptRustGoJavaKotlinRubyPHP

TypeScript

// The app's own client reads its owner's account, never the learner's. The
// slices are all a render knows about the learner.
function planLine(request: AppRenderRequest): string {
  let line = "";
  for (const slice of request.context) {
    // A slice is present only when the learner agreed to share it.
    if (slice.kind === "languages") line += `${slice.source_lang} → ${slice.target_lang}. `;
    if (slice.kind === "plan_summary") line += `${slice.sets_completed}/${slice.set_count} sets.`;
  }
  return line;
}

Rust

// The app's own client reads its owner's account, never the learner's. The
// slices are all a render knows about the learner.
/// The learner's target language and, when they shared their plan, its
/// `(sets_completed, set_count)`.
fn shared_plan(request: &AppRenderRequest) -> (String, Option<(u32, u32)>) {
    let (mut target_lang, mut progress) = (String::from("zh"), None);
    for slice in &request.context {
        match slice {
            ContextSlice::Languages(languages) => target_lang = languages.target_lang.clone(),
            ContextSlice::PlanSummary(summary) => progress = Some((summary.sets_completed, summary.set_count)),
            _ => {}
        }
    }
    (target_lang, progress)
}

// The app's own client reads its owner's account, never the learner's.
// The slices are all a render knows about the learner.
//
// Each slice is present only when the learner agreed to share it.
card := lingaraapps.NewCard().Heading("Your plan", 1)
for _, slice := range req.Context {
	switch s := slice.(type) {
	case lingaraapps.ContextSliceLanguages:
		card.Text(fmt.Sprintf("Learning %s from %s", s.TargetLang, s.SourceLang))
	case lingaraapps.ContextSlicePlanSummary:
		card.Text(fmt.Sprintf("%d of %d sets done", s.SetsCompleted, s.SetCount))
	}
}

Java

import com.getlingara.apps.Card;
import com.getlingara.apps.Reply;
import com.getlingara.apps.model.AppRenderRequest;
import com.getlingara.apps.model.ContextSlice;
import com.getlingara.apps.model.ContextSliceLanguages;
import com.getlingara.apps.model.ContextSlicePlanSummary;

// The app's own client reads its owner's account, never the learner's. The slices are all a
// render knows about the learner.
static Reply render(AppRenderRequest request) {
  Card.Builder card = Card.card();
  // A slice is present only when the learner agreed to share it; the context is read-only.
  for (ContextSlice slice : request.getContext()) {
    if (slice instanceof ContextSliceLanguages languages) {
      card.heading("Learning " + languages.targetLang(), 1);
    } else if (slice instanceof ContextSlicePlanSummary summary) {
      card.text(summary.setsCompleted() + " of " + summary.setCount() + " sets done");
    }
  }
  return card.heading("Today", 2).build();
}

Kotlin

import com.getlingara.apps.kotlin.Reply
import com.getlingara.apps.kotlin.card
import com.getlingara.apps.kotlin.model.AppRenderRequest
import com.getlingara.apps.kotlin.model.ContextSliceLanguages
import com.getlingara.apps.kotlin.model.ContextSlicePlanSummary

// The app's own client reads its owner's account, never the learner's. The slices are all a
// render knows about the learner.
fun renderWithContext(request: AppRenderRequest): Reply {
    // A slice is present only when the learner agreed to share it; the context is read-only.
    val languages = request.context.filterIsInstance<ContextSliceLanguages>().firstOrNull()
    val summary = request.context.filterIsInstance<ContextSlicePlanSummary>().firstOrNull()
    return card {
        heading("Learning ${languages?.targetLang ?: "today"}", 1)
        if (summary != null) {
            text("${summary.setsCompleted} of ${summary.setCount} sets done")
        }
    }
}

Ruby

# The app's own client reads its owner's account, never the learner's. The
# slices are all a render knows about the learner.
#
# A slice is present only when the learner agreed to share it.
request.context.filter_map do |slice|
  case slice
  in Lingara::Apps::ContextSliceLanguages(source_lang:, target_lang:)
    "#{source_lang} → #{target_lang}."
  in Lingara::Apps::ContextSlicePlanSummary(sets_completed:, set_count:)
    "#{sets_completed}/#{set_count} sets."
  else nil
  end
end.join(" ")

PHP

use Lingara\Apps\Generated\ContextSliceLanguages;
use Lingara\Apps\Generated\ContextSlicePlanSummary;

function planLine(AppRenderRequest $request): string
{
    // The app's own client reads its owner's account, never the learner's. The
    // slices are all a render knows about the learner.
    $line = '';
    // A slice is present only when the learner agreed to share it.
    foreach ($request->getContext() as $slice) {
        if ($slice instanceof ContextSliceLanguages) {
            $line .= "{$slice->sourceLang} → {$slice->targetLang}. ";
        } elseif ($slice instanceof ContextSlicePlanSummary) {
            $line .= "{$slice->setsCompleted}/{$slice->setCount} sets.";
        }
    }
    return $line;
}

Context and consent

The slices

What no slice carries

Consent

See also