Telemetry - Posy

A self-hosted Posy sends a small amount of anonymous usage data so we can tell how many instances run, on what, and which looks people publish with. It is on by default in production and takes one setting to turn off.

Turn it off

Any of these, in your environment:

POSY_TELEMETRY=0
DO_NOT_TRACK=1

It is also off automatically in development, in CI and in tests (NODE_ENV is not production, CI is set, or POSY_E2E is set). Posy prints one line the first time it starts with telemetry on:

Posy sends anonymous usage stats (no content, no personal data). Set POSY_TELEMETRY=0 to turn off. Details: https://docs.posy.page/self-host/telemetry

What is sent

Three events, to PostHog (https://us.i.posthog.com, /capture/), with a 2 second timeout. Failures are ignored and never slow the server down.

Event	When	Properties
`posy.instance.started`	Server start	`version`, `node_version`, `os`, `arch`, `deploy` (`docker`, `vercel` or `node`), `db` (`libsql-file` or `turso`)
`posy.instance.alive`	About once a day	`accounts`, `pages`, `published_pages`, each as a bucket (`0`, `1`, `2-5`, `6-10`, `11-50`, `51-100`, `101-500`, `501-1000`, `1000+`)
`posy.page.published`	Someone publishes a page	`look` (for example `washi`), `layout` (`bento`, `list` or `canvas`), `tiles` (bucket)

Every event also carries a random instance id (a UUID Posy creates in telemetry.json inside your data directory; on hosts with a read-only disk, a one-way hash of your auth secret) and the PostHog flags $process_person_profile: false and $geoip_disable: true. Example:

{
  "api_key": "phc_…",
  "event": "posy.page.published",
  "distinct_id": "6c0f3f0e-3a58-4c0a-9d0e-6a9e0a4f1c11",
  "timestamp": "2026-10-16T07:24:00.000Z",
  "properties": { "look": "washi", "layout": "bento", "tiles": "6-10", "$process_person_profile": false, "$geoip_disable": true, "$lib": "posy" }
}

What is never sent

Page content, tile text, links or URLs, usernames, emails, your domain, your database address, API keys, page view counts or any visitor data. We do not store IP addresses (PostHog’s “discard client IP data” setting is on for this project).

Why

Posy is free and open source. Knowing roughly how many instances are running, on which platforms and with which looks tells us what to test, which Node versions to support and which looks are worth the work. Nothing is sold or shared. The code is in src/lib/telemetry.ts and src/lib/telemetry-runtime.ts; read it if you’d like to check. Forks can point it at their own PostHog project with POSY_TELEMETRY_KEY and POSY_TELEMETRY_HOST.

​Turn it off

​What is sent

​What is never sent

​Why

Turn it off

What is sent

What is never sent

Why