Installation

cairn is a Python project managed with uv. The engine ships as one wheel (obsagent/); each operator pack is its own wheel in the same uv workspace.

Requirements

• Python 3.12 or 3.13
• uv

Set up

git clone git@github.com:evs-cmd/cairn.git
cd cairn
uv sync --extra dev          # engine + workspace operators + dev deps

uv sync builds a fresh environment from the lockfile; it is enforced by CI to stay working. The dev extra brings test and lint tooling.

Verify

uv run cairn doctor          # preflight: packs, profile bindings, env, MCP
uv run cairn ls              # list what is installed

doctor is the fastest way to confirm the install is healthy — it checks that packs load, profile bindings resolve to registered operators, and required services are present. See the CLI reference.

Optional extras

Enable only what you need:

Extra	Adds
rag	retrieval-augmented generation support
rag-sqlite-vec	zero-config local vector store
runtime-temporal	the durable Temporal runtime
runtime-dbos	lightweight durable execution (SQLite or Postgres, no server)
runtime-sqlite	cross-restart human-in-the-loop
telemetry	OpenTelemetry export
storage-postgres	Postgres run/state store

uv sync --extra dev --extra rag --extra runtime-dbos

Run the suite

uv run pytest -q