> ## Documentation Index
> Fetch the complete documentation index at: https://docs.aethis.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Try it

> Live rulesets you can curl right now. No signup, no key.

Every example on this page is a live ruleset at `api.aethis.ai`. Anonymous `/decide` accepts a public `ruleset_id` or slug; composed `rulebook_id` lookups need an `x-api-key` header — see [Nomenclature](/concepts/nomenclature#ruleset_id-vs-rulebook_id-on-decide).

<Note>
  This page leads with `curl` because every example is reachable with zero install. The same calls work from the [CLI](/interfaces/cli) (`aethis decide -b <slug> -i '{...}'`), the [Python SDK](/interfaces/python-sdk) (`client.decide(...)`), or via a [coding agent through MCP](/mcp-server/overview) (*"Use Aethis to decide …"*). The [Evaluate a case recipe](/recipes/evaluate-a-case#3-decide) shows the same call across all four interfaces side-by-side.
</Note>

***

## UK Free School Meals — the canonical worked example

Three composed sections (age + school type gate, household means-test, universal infant route). Represents the "rules compiled from legislation" pattern in one compact case.

### Section A — child eligibility (anonymous)

```bash theme={null}
# State-funded Year 5 child, age 10 — Section A alone
curl -X POST https://api.aethis.ai/api/v1/public/decide \
  -H "Content-Type: application/json" \
  -d '{
    "ruleset_id": "aethis/uk-fsm/child-eligibility",
    "field_values": {
      "child.age": 10,
      "child.school_type": "state_funded"
    }
  }'
# → "decision": "eligible"
```

### Sections B (household means-test) and C (universal infant)

Sections B and C live as rulesets *inside* the `aethis/uk-fsm` rulebook rather than as standalone published slugs. They're combined with Section A via the rulebook's `outcome_logic` — see the composed-rulebook call below for the full evaluation that exercises all three.

### The composed rulebook (`A AND (B OR C)`) — requires an API key

```bash theme={null}
curl -X POST https://api.aethis.ai/api/v1/public/decide \
  -H "Content-Type: application/json" \
  -H "x-api-key: $AETHIS_API_KEY" \
  -d '{
    "rulebook_id": "aethis/uk-fsm",
    "field_values": {
      "child.age": 10,
      "child.school_type": "state_funded",
      "child.year_group": "year_5",
      "household.receives_universal_credit": true,
      "household.annual_net_earnings": 6000,
      "household.receives_income_support": false,
      "household.receives_income_based_jsa": false,
      "household.receives_income_related_esa": false,
      "household.receives_child_tax_credit_only": false,
      "household.receives_nass_support": false,
      "child.is_looked_after": false,
      "child.is_care_leaver": false
    }
  }'
# → "decision": "eligible" with per-section breakdown
```

Inspect Section A on its own:

```bash theme={null}
curl https://api.aethis.ai/api/v1/public/rulesets/aethis/uk-fsm/child-eligibility/schema
curl https://api.aethis.ai/api/v1/public/rulesets/aethis/uk-fsm/child-eligibility/explain
```

***

## Spacecraft Crew Certification Act 2049 — the demo rule

Synthetic but carefully built to exercise ENUM, date, and exception-chain logic. Great for agents learning the tool.

```bash theme={null}
curl -X POST https://api.aethis.ai/api/v1/public/decide \
  -H "Content-Type: application/json" \
  -d '{
    "ruleset_id": "aethis/spacecraft-crew-certification",
    "field_values": {
      "space.crew.species": "Vogon"
    },
    "include_trace": true
  }'
# → "decision": "not_eligible" — Vogons are disqualified under Section 3(1)
```

```bash theme={null}
curl https://api.aethis.ai/api/v1/public/rulesets/aethis/spacecraft-crew-certification/schema
```

***

## Construction All Risks insurance — the adversarial benchmark

Five levels of nested exceptions from a real Construction All Risks (CAR) policy. The rule GPT-4 / Claude / Gemini consistently get wrong — and the engine gets right, deterministically, every time.

```bash theme={null}
curl https://api.aethis.ai/api/v1/public/rulesets/aethis/construction-all-risks/schema
```

See the [CAR benchmark narrative](/getting-started/examples#construction-all-risks-insurance) for the full "LLMs get it wrong, compiler gets it right" story.

***

## Consumer credit prequalification

Affordability checks with numeric thresholds + soft-fail paths.

```bash theme={null}
curl https://api.aethis.ai/api/v1/public/rulesets/aethis/consumer-credit-prequalification/schema
```

***

## List every live ruleset

```bash theme={null}
curl https://api.aethis.ai/api/v1/public/rulesets
```

Returns all currently-active public rulesets with their slugs, human-readable names, and rule counts. Always reference a ruleset by its slug (e.g. `aethis/uk-fsm/child-eligibility`); the dated `ruleset_id` underneath rotates on every regeneration but the slug stays stable. See [Decision envelope](/concepts/decision-envelope#ruleset_version--rulebook_id) for the version-pin story.

***

## Next steps

* [MCP server](/mcp-server/overview) — wire the same rulesets into Claude Code / Cursor / Windsurf
* [CLI](/interfaces/cli) — `uv tool install aethis-cli && aethis decide -b aethis/uk-fsm/child-eligibility ...`
* [REST API](/interfaces/rest-api) — full endpoint reference
* [Author your own rules](/authoring/section-discovery) — invite-only private beta