add opt-in telemetry via @acamarata/telemetry (off by default)

README.md

@@ -66,6 +66,11 @@ Full API reference, dynamic algorithm details, traditional method table, and hig
 
 Solar position calculations use [nrel-spa](https://github.com/acamarata/nrel-spa), a port of the NREL SPA by Ibrahim Reda and Afshin Andreas. The seasonal twilight model builds on the work of Khalid Shaukat (Moonsighting Committee Worldwide).
 
+## Telemetry
+
+This package supports opt-in anonymous usage telemetry — off by default.
+Enable: `ACAMARATA_TELEMETRY=1`. See [TELEMETRY.md](./TELEMETRY.md) for what is sent and how to disable.
+
 ## License
 
 MIT. Copyright (c) 2023-2026 Aric Camarata.

TELEMETRY.md

@@ -0,0 +1,8 @@
+# Telemetry Disclosure
+
+This package supports opt-in anonymous usage telemetry via [`@acamarata/telemetry`](https://github.com/acamarata/telemetry).
+
+Telemetry is **off by default**. No data is sent unless you set `ACAMARATA_TELEMETRY=1`.
+
+Full disclosure (what is sent, where it goes, how to disable):
+[github.com/acamarata/telemetry/blob/main/TELEMETRY.md](https://github.com/acamarata/telemetry/blob/main/TELEMETRY.md)

package.json

@@ -88,7 +88,8 @@
     "typedoc": "^0.28.19",
     "typedoc-plugin-markdown": "^4.11.0",
     "typescript": "^5.9.3",
-    "typescript-eslint": "^8.56.1"
+    "typescript-eslint": "^8.56.1",
+    "@acamarata/telemetry": "^0.1.0"
   },
   "type": "module",
   "packageManager": "pnpm@10.11.1",

src/index.ts

@@ -42,3 +42,14 @@ export type {
   AtmosphericParams,
   MethodDefinition,
 } from "./types.js";
+
+// ── Opt-in anonymous telemetry ────────────────────────────────────────────────
+// Off by default. Enable: ACAMARATA_TELEMETRY=1
+// What is sent + how to disable: https://github.com/acamarata/telemetry/blob/main/TELEMETRY.md
+import('@acamarata/telemetry')
+  .then(({ track }) =>
+    track('load', { package: 'pray-calc', version: '2.1.2' }),
+  )
+  .catch(() => {
+    // telemetry not installed or disabled — that is fine
+  });