API question — lightweight way to detect translation updates for mobile caching

[Orlinskas]

Hi Tolgee team,

We're a mobile development team building a KMP (Kotlin Multiplatform) app for iOS and Android. We're using the Tolgee REST API to fetch translations at runtime and cache them on the
device.

This is a non-urgent technical question about the API.

The problem:
We want to avoid fetching all translation keys on every app launch. Instead, we'd like to check whether translations have been updated since our last fetch, and only re-download them
if something has changed.

What we tried:
We're currently hitting GET /v2/projects/{id}/activity?size=1&sort=timestamp,desc to get the latest activity timestamp, then comparing it with a locally stored value. It works, but
we're not sure if this is the intended use case for that endpoint, and we're not confident about the sort behavior.

The question:
Is there a recommended lightweight way to detect whether translations have been updated — something like a last-modified timestamp, a content hash, or an ETag — without fetching all
the keys?

Any guidance would be appreciated.

Thanks!

[Anty0]

Hi @Orlinskas! Thanks for reaching out! ^^

For this use case, I'd recommend setting up Content Delivery. You configure it in your project settings and get a URL that serves your translations. You can set it to auto-publish whenever translations change, so the URL is always up to date. Your app can then use standard HTTP caching against that URL - If-None-Match / If-Modified-Since headers.

It's also worth noting that the export endpoint (GET /v2/projects/{projectId}/export) supports ETag and Last-Modified as well, but it has rate limits, so it isn't very practical for fetching translations from clients.

Hope this helps! Let me know if you have other questions!

[Orlinskas]

Hi @Anty0 , thanks for the quick and helpful response!

One follow-up question — you mentioned the export endpoint has rate limits. Do similar rate limits apply to the other endpoints we're using, specifically GET
/v2/projects/{projectId}/translations?

We're currently using it to fetch all translation keys at runtime on the client side, so it would be good to know if we should expect the same restrictions there.

Thanks again!

[Anty0]

Yee, the translations endpoint (GET /v2/projects/{projectId}/translations) is also rate-limited, so it's not ideal for polling from clients.

Here's a quick overview of endpoints by use case:

• Export endpoint: Manual or CI export to pull static translations for an app release
• Translations endpoint: Dynamically fetch translations during development
• Content Delivery: Dynamically refresh translations client-side in production

Content Delivery has no rate limits - translations are exported once to a blob storage and then served globally via CDN.

[Orlinskas]

Thanks for the clarification!

Could you share the specific rate limit values for those endpoints? For example, requests per minute or per hour — so we can understand at what point in our development or user scale we should prioritize migrating to Content Delivery.

Thanks!

[Anty0]

Hi! Sorry for leaving you hanging without an answer. The rate limits have been a bit fluid lately (read as: "we were adjusting them"), so I don't have exact numbers. Do you think we should publish them? Maybe we'll create a generated documentation page for this later so users don't have to guess.

As a rule of thumb: Internally, fetch from Tolgee; externally (users/clients), fetch from the CDN. Don't give your users API tokens. They can prevent you from accessing your account (a denial-of-service of sorts) when you reach the rate limit. Since the CDN is available even on free plans, I'd say there's no reason not to use it. ^^

Hope this helps!