Quickstart

Goal: gate a real write-path action with decide(), persist a Decision Record, and export/replay it under incident pressure.

Requirements

Python >=3.11
Optional: curl + jq

1) Install

pip install lumyn

2) Create a workspace

This creates .lumyn/lumyn.db and the default policy.yml (v1):

lumyn init

3) Make a decision

Create a request.json file (v1 schema):

{
  "schema_version": "decision_request.v1",
  "request_id": "req_123",
  "subject": {"type": "service", "id": "support-agent", "tenant_id": "acme"},
  "action": {
    "type": "support.refund",
    "intent": "Refund duplicate charge",
    "amount": {"value": 12.0, "currency": "USD"}
  },
  "evidence": {
    "ticket_id": "ZD-1001",
    "payment_instrument_risk": "low"
  },
  "context": {"mode": "digest_only", "digest": "sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"}
}

Run CLI decision:

lumyn decide request.json --pretty

[!TIP] Open a second terminal and run lumyn monitor to see a live "Matrix-style" feed of decisions as they happen!

4) Incident flow (show / explain / export / replay)

Get the decision_id from the output above, then:

lumyn show
lumyn explain --markdown
lumyn export --pack --out incident.zip
lumyn replay incident.zip

5) Service mode (optional)

lumyn serve

Call with curl:

curl -sS -X POST http://127.0.0.1:8000/v1/decide -H 'content-type: application/json' --data-binary @request.json | jq .