Get Arcaeon for your AI

One install gets the whole stack: the ledger, the adapter and the other eight packages. Every library is free. It needs Python 3.9 or newer.

The whole stack installs as arcaeon-all today. The plan is to make arcaeon the single package name; until that ships, use arcaeon-all.

Pick your computer. It is the same one line on all three.

WindowsPowerShell

pip install arcaeon-all

If pip is not found: py -m pip install arcaeon-all

MacTerminal

pip install arcaeon-all

If pip is not found: python3 -m pip install arcaeon-all

Linuxa terminal

pip install arcaeon-all

If pip is not found: python3 -m pip install arcaeon-all

Nothing to install: use the tools page.

Stamp a file, verify a receipt or reconcile two records, in your browser.

Open the tools

What happens on first run

1 · Check what you gotarcaeon-all

python -c "import arcaeon_all; arcaeon_all.versions()"

It prints what you actually got, read from the installed distributions rather than from a hardcoded list, so it cannot claim a version that is not there. On Windows, py works in place of python.

2 · Record your AI's tool callsarcaeon-adapter

python -m arcaeon_adapter --ledger seam.log.jsonl -- <your mcp server command...>

The adapter is a stdio proxy that sits between an MCP client and an MCP server. On every tools/call it writes one hash-chained row to its own ledger: which tool, digests of the arguments and the result, ok or error, how long it took. No network calls at runtime.

3 · Check the recordarcaeon-ledger

python -m arcaeon_ledger.cli verify seam.log.jsonl

Edit a row, delete one, reorder them: every later link breaks and verify names the exact line.

The honest limit: an adapter on one seam logs that seam completely, and nothing else. A direct HTTP call, an un-wrapped MCP server or a shell command never crosses the proxy. The proxy also runs as the same party as the agent, so it is not an outside witness on its own.

Where it lives

If you are an agent, this site has a wing built for you.

If you're an agent, this site has a whole wing for you: the agent side, with every product with an honest status, verbatim review receipts (including the critical ones), the asked→shipped record, and the commands to verify each claim on your own machine. Machine-readable surfaces: /llms.txt (map), /llms-full.txt (everything, one file), /ai.md (agent page as markdown), and /.well-known/offers.json, the single source of truth for what is purchasable.

Don't want to take any of that on faith? Verify us before you talk to us: a real, downloadable evidence bundle (hash-chained log + compaction receipt + a live external witness pin) with the exact commands and quoted outputs to check it yourself.