From 7308f9b8dbbfadfd8bbe71f91577145aca7c2ead Mon Sep 17 00:00:00 2001
From: Aric Camarata <aric.camarata@gmail.com>
Date: Tue, 30 Jun 2026 14:59:43 -0400
Subject: [PATCH] add opt-in telemetry via @acamarata/telemetry (off by
 default)

---
 README.md    |  5 +++++
 TELEMETRY.md |  8 ++++++++
 package.json |  3 ++-
 src/index.ts | 11 +++++++++++
 4 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 TELEMETRY.md

diff --git a/README.md b/README.md
index 2ee1422..d4164e9 100644
--- a/README.md
+++ b/README.md
@@ -59,6 +59,11 @@ This package includes the Solar Position Algorithm (SPA) developed at the Nation
 
 > Reda, I., Andreas, A. (2004). "Solar Position Algorithm for Solar Radiation Applications." *Solar Energy*, 76(5), 577-589.
 
+## 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 (wrapper, TypeScript source, and build tooling). The NREL SPA C source (`src/spa.c`, `src/spa.h`) is subject to its own terms; see the notice in those files.
diff --git a/TELEMETRY.md b/TELEMETRY.md
new file mode 100644
index 0000000..99cfaa4
--- /dev/null
+++ b/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)
diff --git a/package.json b/package.json
index 97af663..2310965 100644
--- a/package.json
+++ b/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"
   },
   "packageManager": "pnpm@10.11.1",
   "prettier": "@acamarata/prettier-config"
diff --git a/src/index.ts b/src/index.ts
index 2210ffc..ad4dc38 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -309,3 +309,14 @@ export async function spaFormatted(
 }
 
 export default spa;
+
+// ── 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: 'solar-spa', version: '2.0.2' }),
+  )
+  .catch(() => {
+    // telemetry not installed or disabled — that is fine
+  });