# Download statistics

This directory turns the cran.rpkgs.com CDN access logs into the public download numbers on [rpkgs.com/stats](https://rpkgs.com/stats).
The `download-stats` pipeline runs it every hour.

## Data flow

1. `collect.ts` reads the last 70 hours of access logs from the Bunny Logging API v2 and inserts each request into `download_stats.events` in the build metadata database.
2. `classify.ts` derives what each request was (package download, index fetch, redirect, probe, noise) from its path, status and User-Agent.
3. `publish.ts` aggregates the events into `stats/downloads.json` in the binaries bucket and purges its CDN copy, so it is served at <https://cran.rpkgs.com/stats/downloads.json>.

Bunny keeps access logs for three days.
Each hourly run re-reads almost all of that window, and events are keyed by Bunny's request id, so re-reading never double counts and up to two days of failed runs lose nothing.
Every run is recorded in `download_stats.runs`, and the dashboard marks any hour that no run covered.

## Privacy

Bunny anonymizes IPs at the edge to /24 (IPv4) or /64 (IPv6) before they reach the logs.
Not even that prefix is stored: each event keeps only `client`, an HMAC (keyed with `STATS_CLIENT_SALT`) of the prefix, the network (ASN) and the client platform from the User-Agent.
The public JSON contains counts only, never a client hash, IP or User-Agent.
Countries seen from fewer than three clients are folded into "other".

## What counts

| Metric     | Definition                                                                                                                                                                       |
| ---------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Download   | A distinct (client, package, version) served on one UTC day. Raw tarball requests are reported separately, because one CI job can re-download the same package many times a day. |
| Client     | A distinct `client` hash that fetched an index or a package. Several machines behind one /24 count once, and one laptop on two networks counts twice, so this is an estimate.    |
| Client-day | A client active on a given day, roughly one install session.                                                                                                                     |

The same R session seen with and without renv's User-Agent prefix counts as one client, since `clientPlatform()` keys on the R part of the User-Agent.

## What is separated or excluded

- **Cloud and CI networks** are kept but reported separately: Microsoft/GitHub, AWS, Google, Hetzner, OVH and other hosting ASNs, plus any network whose name says hosting, cloud or data centre.
- **Our own CI runners** (`STATS_OWN_NETWORKS`) are excluded from every public number and only counted as excluded requests.
- **Internal redirects** (`minor_routing`, `slot_resolution`, `https`) are not counted, only the request they lead to.
- **Redirects away from us** are counted as their own metrics: `unsupported_r_minor` (demand for R versions we do not build), `archive_fallback` (old versions we have no binary for), `unknown_distro` and `macos`.
- **Probes**: renv and pak request `__api__/status` to check for Posit Package Manager.
- **Noise**: vulnerability scanners, crawlers and anything outside the repository layout.

## Changing the rules

Change `classify.ts`, add a test case to `classify.test.ts` and bump `RULESET`.
Then recompute every stored event:

```sh
bun stats/collect.ts --reclassify
```

The raw path, status, User-Agent and network are stored for exactly this reason.
Whether a request came from our own runners is decided at ingest, so changing `STATS_OWN_NETWORKS` only affects new events.

## Running locally

The secrets are in OpenBao: the Bunny key at `development/agent-dev/bunny`, the database password at `development/agent-dev/rpkgs-metadata-db` and the salt and own networks at `development/agent-dev/rpkgs-download-stats`.

```sh
bun test stats
bun stats/collect.ts
# write the JSON locally instead of uploading it
bun stats/publish.ts --out downloads.json
```