Live Demos

Eight demos run the real Precomputing code right here in your browser. Six keep answers ready from their own kind of data. Two show what that gives AI agents: an agent that reads the SQL, Engine, Meter and Logs demos’ files over MCP, and a day of coding-agent calls kept once and metered. They are open to everyone with no sign-up, and nothing you do here is sent anywhere. Seven of them play simulated or generated data and end by checking every answer against a recount made by separate code. The Wikipedia demo takes real changes from Wikimedia’s public stream as they happen and checks itself as it goes.

Real code, and one demo on real data. The traffic, the trades, the usage, the log lines and the agent runs come from fixed scripts. The Wikipedia demo reads real changes. Whatever a demo runs is the real thing, built for WebAssembly: the compiler, the Engine, the log reducer, the MCP server, the store of agent calls and SQLite.

SQL: Precomputing Inside Any SQLite

The SQL demo at the end of a run: 1,080,198 requests, the raw table at 35.2 MB against the precomputed file at 4.5 MB, and p99 latency minute by minute for five endpoints.

Three hours of API traffic for a small web service go through a compiled policy in SQLite. Watch the raw table grow with traffic while the precomputed file grows with time, add slow requests, start an outage, then ask the file anything in SQL. Open the SQL demo

Engine: The Same Policy at Native Speed

The Engine demo paused at 11:26 New York time: SIM4’s 1-minute candles with its 8% jump marked, under the Engine’s live figures.

A trading day of about four million stock trades turns into candles, drawn from the file as the Engine writes it. Pull the plug in the middle of a write, race the Engine against the compiled SQL, and check every closed candle at the end. Open the Engine demo

Meter: Exact Usage and Quotas

The Meter demo paused on 28 September: the live figures and six customer cards with their spend and quota bars, Juniper Bakery Blog’s quota reached.

A month of AI usage from six customers goes through two gateways into one meter. Start a retry storm or cut a link: every request is still billed once, in the hour it happened, and September’s invoices come out equal to a recount to the billionth of a dollar. Open the Meter demo

Logs: Answers Go Up, Lines Stay Home

The Logs demo paused at 12:43: dashboard panels drawn from what was sent upstream, with the payment incident marked, and the top searches.

Two hours of a web shop’s logs go through the log reducer. It learns the kinds of line as they arrive, sends a six-panel dashboard upstream as answers, catches a payment incident as a new kind of error and keeps every line on site for search. Open the Logs demo

Wikipedia: Every Change, Live

The Wikipedia demo running on its simulated changes: the articles several people are editing, and the busiest wikis with the share of changes made by bots.

Every change to every Wikipedia and every other Wikimedia wiki, from Wikimedia’s public stream, straight into the Engine in your browser. See what people are editing right now and which wikis are busiest, pick a wiki, and watch a recount check every count in the file. Open the Wikipedia demo

Incident Déjà Vu: Has This Happened Before?

The Incident Déjà Vu demo paused at 12:18: it looks like incident #1, the northpay outage, with what fixed it, told apart from the quickcard outage by the raw lines.

The web shop carries on for two more hours, on a file that holds its day before and six incidents the on-call team wrote down. Every ten seconds the file says what stands out and which past incident it looks like, with what fixed it. A new kind is flagged as new; write it down and it is recognized the next time. Open the Incident Déjà Vu demo

MCP: An AI Agent Reads the Files

The MCP demo after its four questions: 11 tool calls, 785 tokens in the answers and 1,776 reading what each file keeps, against 5,329,439 tokens for the raw data, 2,081 times more, with 19 of 19 checks passed.

The SQL, Engine, Meter and Logs demos’ files, each faded as its policy says, get an MCP server of their own. An agent reads what each file keeps, then asks four questions: a p99, a candle, an invoice and what went wrong in the logs. Each answer is a few hundred tokens where the raw data would take hundreds of thousands, and a recorded session shows a real agent at work. Open the MCP demo

Traces: Agent Calls Kept Once and Metered

The Traces demo paused at 11:41: 840 model calls kept, 56.8 MB as sent against 3.5 MB in the file, and tallowcraft/tarnforms past its $0.20 budget for the day, with the alert at the top of what happened.

A day of 100 coding-agent runs goes through the store of agent calls. Each message is kept once however many calls resend it, secrets are masked first, and any call can be rebuilt byte for byte. Every call is metered by run, repository and source, and a stuck run sets off a budget alert. Open the Traces demo

What the Demos Have

  • A run to watch or to skip. A simulated run left alone ends with the numbers published on the Platform page, and Review the results finishes it at full speed. The Wikipedia demo runs for as long as the page is open, and the MCP demo asks its questions instead.
  • Something to break. Six demos have a button that makes the day harder: a slow request, an outage, a pulled plug, a retry storm, a broken search shard, a run reported twice or an incident of your choice. In the MCP demo you can send the server any message, mistakes included.
  • The policy. The policy the demo runs and the SQL it compiles to, and in most demos a box to change it and compile it again with the real compiler.
  • The checks. Every answer next to the same answer recounted from the events as they were sent, by code that never reads the file. The simulated demos check at the end of a run, and the Wikipedia demo every 30 seconds.
  • Ask the file. The file is plain SQLite. Pick a ready-made question or write your own, and download the file to open it in any SQLite tool.

What Your Browser Needs

Any current Chrome, Edge, Firefox or Safari, on a computer or a phone, with JavaScript switched on. The demos need WebAssembly, which all of these browsers support. The code comes from this site: SQLite built for the browser (1.5 MB, 577 KB compressed), and for the Engine, Logs, Wikipedia, Incident Déjà Vu, MCP and Traces demos the Go program that runs them, with the MCP server and the store of agent calls (5.9 MB, 1.6 MB compressed). The Incident Déjà Vu demo also downloads the file of the day before (0.73 MB compressed), and the Wikipedia demo connects to stream.wikimedia.org. The files the demos write live in the page’s memory and go away when you close it.