Who's still on the old client?

Why this matters

Old mobile clients are a slow-moving operational tax:

• They hit endpoints you’ve already deprecated, forcing you to maintain shims
• They crash on patterns you’ve already fixed, dragging your aggregate crash-free metric down
• They miss the security fix you shipped last quarter
• They prevent you from removing legacy fields from your API contract

The fix is usually a force-update prompt — but you can’t make that call without knowing the population. Force-updating 80% of your users is a PR disaster. Force-updating 4% is a Tuesday.

Agentry gives you the distribution in one query: distinct users per version over a 7-day window. The N-2-or-older percentage tells you whether the force-update is now or later.

What you get

• Per-version distinct user count and rollout share
• N-2-and-older count and percentage — the “force update” candidate population
• A published dashboard for the mobile/ops team to pull up at release planning

Walk through it

agentry_analytics_query {
  project_id: "default",
  query: "
    select
      properties.app_version as ver,
      count(distinct distinct_id) as users
    from events
    where event = 'app_open'
      and timestamp > now() - interval 7 day
    group by ver
    order by ver desc
  "
}

{
  "rows": [
    { "ver": "4.2.0",  "users":  68420 },
    { "ver": "4.1.3",  "users": 142100 },
    { "ver": "4.1.2",  "users":  61880 },
    { "ver": "4.1.1",  "users":  18340 },
    { "ver": "4.0.5",  "users":   8400 },
    { "ver": "4.0.4",  "users":   2300 },
    { "ver": "3.9.2",  "users":   1840 },
    { "ver": "3.8.1",  "users":    420 }
  ]
}

agentry_analytics_query {
  project_id: "default",
  query: "
    with d as (
      select properties.app_version as ver,
        count(distinct distinct_id) as users
      from events
      where event = 'app_open' and timestamp > now() - interval 7 day
      group by ver
    )
    select
      sum(users) as total_users,
      sumIf(users, ver >= '4.1.3') as latest_or_n_minus_1,
      sumIf(users, ver <  '4.1.3') as n_minus_2_or_older
    from d
  "
}

{
  "rows": [
    { "total_users": 303700, "latest_or_n_minus_1": 210520, "n_minus_2_or_older": 93180 }
  ]
}

agentry_publish_query {
  recipe_id: "raw_hogql",
  description: "App version distribution (7d)",
  params: { query: "<first query above>" }
}

{ "publication_id": "pub_ver_dist", "public_url": "https://agentry.sh/q/pub_ver_dist?key=agp_…" }

The output

App version distribution (7d distinct users)

Version    Users      Share    Cumulative
─────────────────────────────────────────────
4.2.0       68,420   22.5%     22.5%       ← current
4.1.3      142,100   46.8%     69.3%       ← N-1
4.1.2       61,880   20.4%     89.7%       ← N-2 ★ force-update candidate
4.1.1       18,340    6.0%     95.7%
4.0.5        8,400    2.8%     98.5%
4.0.4        2,300    0.8%     99.3%
3.9.2        1,840    0.6%     99.9%       ★ 18 months stale
3.8.1          420    0.1%    100.0%       ★ ancient — force update

Recommended:
  - Force-update 3.x users now (low PR risk, ~2,260 users)
  - Wait one more release before force-updating 4.0.x
  - Set up Routine to alert when latest reaches >40% adoption

Public dashboard:
  https://agentry.sh/q/pub_ver_dist?key=agp_xxx

Setting it up

You only need app_version on a regular event — typically app_open or session_start:

// Android — fire on cold start
postAnalytics("app_open", mapOf(
  "app_version" to BuildConfig.VERSION_NAME,
  "platform" to "android",
  "os_version" to Build.VERSION.RELEASE
))

// iOS — fire from AppDelegate.application(_:didFinishLaunching...)
postAnalytics("app_open", [
  "app_version": Bundle.main.releaseVersion,
  "platform": "ios",
  "os_version": UIDevice.current.systemVersion
])

Where postAnalytics is your fetch helper:

async function postAnalytics(event: string, properties: Record<string, unknown>) {
  await fetch(`https://api.agentry.sh/v1/analytics/${PROJECT_ID}/`, {
    method: "POST",
    headers: {
      "Authorization": `Bearer ${DSN}`,
      "Content-Type": "application/json",
      "User-Agent": "myapp/1.0",  // REQUIRED — Cloudflare 403s default UAs
    },
    body: JSON.stringify({ event, distinct_id: userId, properties }),
  });
}

Variations

• “Same query split by platform — iOS adopters tend to update faster than Android.”
• “Per-country distribution — emerging markets have older OS versions and slower updates.”
• “Show me the adoption curve of v4.2.0 day-by-day since release. Is it tracking last release’s curve?”
• “Compare crash-free rate of users on N-2 vs latest — are old-clients-still-using-the-API hitting issues that newer ones don’t?”