Playground

The playground runs every Halos component on Docker with a seeded policy repo: the console and self-service portal behind an OIDC login, halo-proxy, halo-shadow, mock model upstreams and the evidence plane (collector, ClickHouse, Grafana). Nothing talks to a real model provider or cloud account. It is dev only: the IdP signs in anyone, and every key and token is generated at start and deleted on teardown.

A coding CLI calls halo-proxy, which verifies the caller's identity, resolves ring, experiment and toggle, rewrites the model and forwards to the upstream.

Start it

With halo installed (Docker and git on the machine):

halo quickstart          # clones a Halos checkout into ~/.cache/halos/src if needed, then runs make demo
halo quickstart down     # later: stop it and delete its volumes

In the browser: . The dev container builds bin/ and puts it on PATH; run make demo in its terminal and open the forwarded Halos console port (UNVERIFIED: CI builds the dev container with the devcontainer CLI, but make demo has not been run in a real Codespace).

From a checkout (Docker with Compose v2.20+, Go to build bin/):

make demo                # make demo-down removes it

A one-shot seed container copies examples/acme-corp plus a small overlay (deploy/compose/demo/policy: mock upstreams, the shadow experiment running at 100%; halos.yaml is patched to the mock IdP issuer), generates throwaway keys, publishes a signed release per ring to a local registry:2 and compiles policy.json. When everything is healthy it prints:

What	URL
Console + portal	`http://localhost:18080` (Sign in, pick a demo user)
Mock IdP (OIDC)	`http://localhost:18081/.well-known/openid-configuration`
halo-proxy (model API)	`http://localhost:18088/v1/messages`
halo-shadow metrics	`http://localhost:18090/metrics`
Grafana	`http://localhost:13000` (`admin` / `halo-dev-only`)

Demo user	Groups	Lands in
`alice@acme.com`	`ai-platform`	`ring0-harness-team`, admin
`bob@acme.com`	`eng`	`ring2-early` (claude-cli A/B, sonnet shadow)
`mallory@acme.com`	`eng`	`ring1-canary` (opus-5-5 canary)
`dave@acme.com`	`eng`	`ring3-ga`

The seeded repo is examples/acme-corp, a full-mode repo with every document written out so each feature has something to show. Your own repo would usually start as one file: halo init writes a simple-mode halos.yaml, and halo explain --policy-dir examples/simple shows what the examples/simple file expands to.

The seeded repo has three running experiments, the opus-5-5-upgrade rollout active at step canary-5, and three toggles, including sonnet-next-route (ring0’s sonnet goes to the next model).

Try this

Sign in. Open the console, click Sign in and choose alice@acme.com. The mock IdP runs a real authorization-code + PKCE flow, so the console sees exactly what it would from Okta or Entra. The same flow with curl:

GET /auth/login            -> 302 http://localhost:18081/authorize?...&code_challenge_method=S256
GET /authorize&user=alice  -> 302 http://localhost:18080/auth/callback?code=...&state=...
GET /auth/callback         -> 302 http://localhost:18080/
GET /api/v1/me             alice@acme.com ['ai-platform'] admin=True ring=ring0-harness-team
GET /api/v1/experiments    claude-cli-2.1.3xx-ab running, opus-5-5-canary running, sonnet-next-shadow running
GET /api/v1/rollouts       opus-5-5-upgrade active canary-5 (plus two drafts)

Call the model API as three users. Each token comes from the mock IdP; a spoofed x-halo-ring: ring3-ga header is ignored because the cohort comes from the verified token.

TOK=$(curl -s 'localhost:18081/token?user=bob@acme.com&groups=eng')
curl -s localhost:18088/v1/messages -H "Authorization: Bearer $TOK" \
  -H 'content-type: application/json' -H 'anthropic-version: 2023-06-01' \
  -H 'x-halo-ring: ring3-ga' \
  -d '{"model":"sonnet","max_tokens":5,"messages":[{"role":"user","content":"hi"}]}'

alice sonnet:  served-by=anthropic model=claude-sonnet-5-5  x-halo-ring:ring0-harness-team
bob sonnet:    served-by=orch model=us.anthropic.claude-sonnet-4-5-v1:0  x-halo-experiment:claude-cli-2.1.3xx-ab x-halo-ring:ring2-early x-halo-variant:control
mallory opus:  served-by=orch model=us.anthropic.claude-opus-4-1-v1:0  x-halo-experiment:opus-5-5-canary x-halo-ring:ring1-canary x-halo-variant:control
no token:      {"error":{"type":"unauthorized","message":"invalid or missing credentials"}}

Alice’s sonnet goes to the next model because the sonnet-next-route toggle targets ring0.

Kill the toggle. On the console’s Toggles page (as alice), kill sonnet-next-route (or halo toggle kill with her session cookie). halo-proxy polls the signed kill list every 2s here, so alice’s next request falls back to the default route with no release and no policy PR:
```
POST /api/v1/toggles/sonnet-next-route/kill    -> 200
alice sonnet:  served-by=orch model=us.anthropic.claude-sonnet-4-5-v1:0
POST /api/v1/toggles/sonnet-next-route/unkill  -> 200
alice sonnet:  served-by=anthropic model=claude-sonnet-5-5
```

Watch the shadow. Only requests that carry a session id are mirrored, and only first turns unless the experiment sets turns: all (Claude Code sends x-claude-code-session-id, Codex session_id), so add that header to Bob’s call. The mirror goes to the candidate route; users only ever see the primary reply.

curl -s localhost:18088/v1/messages -H "Authorization: Bearer $TOK" -H 'x-claude-code-session-id: demo-1' \
  -H 'content-type: application/json' -H 'anthropic-version: 2023-06-01' \
  -d '{"model":"sonnet","max_tokens":5,"messages":[{"role":"user","content":"hi"}]}'

$ curl -s localhost:18090/metrics
halo_shadow_mirrored_total 1
halo_shadow_spend_usd 0.001092
halo_shadow_budget_usd 5

See the evidence. halo-proxy exports halo.gateway.* metrics to the collector every 5s. Grafana’s Halos: fleet and experiments dashboard reads them from ClickHouse.
Manage a feature toggle. Open Toggles in the console, pick github-mcp, and try Who gets it? with a user and groups. Kill needs a reason and reaches halo-proxy at its next poll (every 2 s in the playground). Propose change (for example, ramp the rule to 25%) validates the edit and opens a “PR”. In the playground that PR is only a local branch: the stack has no GitHub, so halo-server pushes halos/toggle-... to a bare repo on the policy-repo volume and a stub gh prints where it landed. Nothing merges, and the served policy does not change. Inspect it with docker run --rm -v halos-demo_policy-repo:/repo --entrypoint git halos-demo/halo-server -C /repo/remote.git branch.

Tear down

make demo-down    # stops every container and deletes the volumes (keys, releases, data)

Troubleshooting

A port is taken. Every host port binds to 127.0.0.1 and is overridable: HALO_DEMO_CONSOLE_PORT, HALO_DEMO_IDP_PORT, HALO_DEMO_PROXY_PORT, HALO_DEMO_SHADOW_METRICS_PORT, and for the evidence plane HALO_OBS_GRAFANA_PORT, HALO_OBS_CH_HTTP_PORT, HALO_OBS_OTLP_*_PORT. Pass the same values to make demo-down.
A service never got healthy. The script names it; docker compose -f deploy/compose/docker-compose.demo.yml logs <service> shows why. seed failing usually means the registry was not reachable.
Login loops back to the IdP. The console’s redirect URI and the IdP’s browser URL are derived from the ports above (HALO_DEMO_CONSOLE_URL, HALO_DEMO_IDP_URL override them). In a Codespace the script uses the forwarded https://<codespace>-<port>.app.github.dev URLs.
Start over. make demo-down && make demo reseeds from scratch.