Observability pack 1: the architecture

From the PHP newsroom's observability, as it runs since 22 October 2026 (built by observability@php.newsroom, editor Dinis Cruz). Studied by conductor@web-summit.dinis on 4 November 2026 from its two vaults (keys handed over by Dinis, sealed) and the site's public repository.

The flow

 reader's browser                         dev.send.sgraph.ai                      the drain (an agent, or the app)
 ┌──────────────────────────┐            ┌──────────────────────────────┐        ┌──────────────────────────────────┐
 │ assets/telemetry.js      │  POST      │ telemetry vault 84wr8mib     │  list  │ admin/build/telemetry_drain.py    │
 │ 1 event / page / session ├──write───►│  lane 1..5 (append tokens)   ├─fetch─►│ or the app's Queue & drain page   │
 │ sealed to the drain key  │  (blind)   │  bare/append/<token>/pending │  mark  │ opens each with the drain key     │
 └──────────────────────────┘            └──────────────────────────────┘        │ -> drain/<date>.jsonl (private)   │
                                                                                 │ -> reports/<date>.json (counts)   │
                                                                                 │ -> site data/telemetry-report.json│
                                                                                 └──────────────────────────────────┘
 the app vault 5wnsr5h8 (code only) ── linked read-only at telemetry-ux/ ──► the telemetry vault's index.html renders it

The parts

Part	Where	What it is
The sender	the site: `assets/telemetry.js`, `data/telemetry.json`	~100 lines; seals the event in the browser (pack 2)
The lanes	the telemetry vault's append lanes	write-only; the token is published; the write response is blind (pack 3)
The data vault	`84wr8mib`, private	identity (keys), `drain/`, `reports/`, a link to the app (pack 3)
The drain	`admin/build/telemetry_drain.py` (Python) and the app's `drain.js` (browser)	list, fetch, open, append, mark processed, count (pack 4)
The classes	`admin/build/telemetry_classes.py` and the app's `classes.js`	who sent a session: reader, team, synthetic, crawler (pack 4)
The public report	the site's `data/telemetry-report.json` and `data/telemetry-public.json`, rendered at `/admin/telemetry/`	counts only (pack 4)
The app	vault `5wnsr5h8`, code only, versioned	the interactive view over the data vault (pack 5)

Why this shape

No server of our own: the site is static (GitHub Pages); the only server is the vault host, which stores ciphertext.
Write-only from the web: the append token can write and nothing else; it cannot list, read or delete, and every write returns exactly {"ok": true}. So it is safe to publish.
Encrypted at the source: the browser seals each event to the drain's public key; the host never sees an event.
Data and code apart: the data vault holds keys and rows; the app vault holds only code (its read key can be published), so one app version serves every data vault that links it.

What changes for us

Pack 6: a person's signature on the event, a public vault (at Dinis's word), and a third lane for agents' runs.