Demo: two owners, one account

An account Alice and Carol hold together. Ask its agent a question and watch neither of them be able to answer it alone.

Left screen — Terminal, ~/uma4agents Right screen — two portals, portal.uma.lab and carol-portal.uma.lab

Pre-demo setup

From cold to ready. Four commands on a Mac, two in a Codespace, about 20 minutes.

1 · Once per machine. Points your OS resolver at the lab's DNS so *.uma.lab works in a browser. One sudo. Skip both in a Codespace — it uses /etc/hosts instead.

brew install kind helm
make dns-setup

2 · Build the lab. Three-node kind cluster, Istio ambient, kgateway, cert-manager, CloudNativePG, and every party in its own namespace. ~13 minutes cold. If the compose stack is running it will stop you — both want :443 and :53, so run make down and try again.

make kind-up

3 · Trust the CA. cert-manager issues the lab CA inside the cluster; this trusts it locally so the portals load with no warning. Re-run after every kind-up — a new cluster means a new CA. In a Codespace run make codespaces-web instead.

make k8s-trust-ca
sudo security add-trusted-cert -d -r trustRoot \
  -k /Library/Keychains/System.keychain /tmp/u4a-k8s-ca.pem

4 · Bring up the agent. kagent's controller, the U4A adapter in Bob's namespace, and a model for the agent to think with. Your key goes into a Kubernetes Secret and nowhere else.

export ANTHROPIC_API_KEY=sk-ant-...
make kagent

Open https://portal.uma.lab (alice / alice-demo) and https://carol-portal.uma.lab (carol / carol-demo) side by side on the right screen.

In a Codespace. Only steps 2 and 4. No resolver to edit, no CA to trust — kind-up publishes the portal for you. To republish it later:

make codespaces-web

Running it again. No reset needed. A fresh agent key every run, so both holders are always asked — and the demo puts the account back as it found it.

make k8s-reset

Switching the model

Another provider key:

export OPENAI_API_KEY=sk-...
make kagent MODEL=openai

Another model:

ANTHROPIC_MODEL=claude-sonnet-5 make kagent
OPENAI_MODEL=gpt-4o make kagent MODEL=openai

A model in the cluster instead:

make kagent MODEL=ollama

The run-through

Two portals on the right, not one. Steps 1 to 3 are the two of them agreeing to hold something together — do them live, they are half the point.

0 · Terminal. Show the whole lab first. Every party in its own namespace. Point out tally: it is its own party, it owns nothing, and it is about to be the thing neither owner has to trust.

make k8s-status

1 · Alice's portal — Agent Access → Joint accounts. She reads the deal before she agrees to it. It names Carol as the other holder and says "Every holder has to allow a request. Any one of you can stop it." Tick the box and Join. Her authority refuses a join without that tick, and records what she agreed to.

Where it is counted:  https://joint-tally.uma.lab
Account:              meridian-joint

Then See what this commits you to.

2 · Carol's portal — Agent Access → Joint accounts. Same two values. Two people, two authorities, one account. Neither was enrolled by the other naming her — being a co-owner is something you agree to, not something done to you.

3 · Both portals — My Terms → new tier. Each writes her own terms, at her own authority. Alice is looser on every field on purpose, so that every narrowing you see in step 7 came from Carol. Terms over something held jointly get a tier of their own — one edit here would change what the other holder's agents are held to.

              ALICE                 CAROL
Name it:      Joint - Alice         Joint - Carol
Governs:      meridian-joint        meridian-joint
Expires after: 3600                 900
Prohibited:   model-training        resale-to-third-parties

4 · Terminal. Point Bob's agent at the joint account. Nothing about the agent is joint-aware. The resource publishes its own authority, so it finds out it needs two people by asking, not by being configured.

make kagent RESOURCE=joint

5 · Terminal — held jointly · all of 2. It stops, and two portals light up. One question, asked of one agent, has become a decision waiting on two different people at two different authorities.

make kagent-ask RESOURCE=joint Q="What is in the joint account?" SIM=0

6 · Alice's portal — Approve. One of two. Alice says yes and nothing happens. Let it sit for a beat. The terminal is still waiting. One holder is not a decision, and there is no majority to round up to.

7 · Carol's portal — Approve. Both · granted. Now it completes: VTSAX, VBTLX, MMDA. Read the folded document out of the log — 900 seconds (Carol's, the shorter), positions:read only (all they both offer), and both prohibitions. One agreement, made of two people's terms. The grant carries a signed verdict from each holder, and the enforcement point re-ran the count itself before letting it through — so a tally that invented a yes dies at the door.

8 · Terminal. Now ask it to move their money. Both are asked again. Nothing was carried over from last time — the previous grant was spent.

make kagent-ask RESOURCE=joint Q="Sell 400 shares of VTSAX from the joint account." SIM=0

9 · Carol's portal — Deny. Refused. Carol refuses, and it is over immediately. Alice is never asked. Under a mandate that needs everybody, one refusal settles it and nobody waits for the rest — which is also why the tally cannot stall a decision by sitting on it.