API Reference

Base URL

https://api.aethis.ai/api/v1/public/

Authentication

x-api-key: ak_live_...

Evaluation and read endpoints on published public rulesets require no authentication: POST /decide, GET /rulesets, and GET /rulesets/{id}/schema · /explain · /graph, plus POST /rulesets/{id}/explain-failure. Authoring endpoints (/projects/, /generate-and-test, /publish, /guidance) require an x-api-key header and are invite-only private beta. Call them from your server — never expose an API key to client-side code.

Browser access is scoped per route and method, not granted to “decision endpoints” as a class. Only the enumerated evaluate/read surface answers a cross-origin request from an arbitrary origin, without credentials; every other route — authoring included — is restricted to first-party origins. See the full route matrix before calling this API from client-side code.

Request an API key → · What each tier includes

Endpoint groups

Decision

Evaluate eligibility against a published ruleset. No auth required. Under 1ms in the engine.

POST /decide
GET /rulesets/{id}/schema
GET /rulesets/{id}/explain

Projects (invite-only)

Author rules from source text using a test-driven workflow. Requires an API key from the invite-only authoring beta.

POST /projects/
POST /projects/{id}/generate-and-test
POST /projects/{id}/publish
POST /projects/{id}/guidance

Rulesets

Inspect, list, and manage published rule rulesets.

GET /rulesets/
GET /rulesets/{id}/schema
GET /rulesets/{id}/explain
PATCH /rulesets/{id}/visibility
POST /rulesets/{id}/archive

Rulebooks

Compose multiple section rulesets into a single rulebook with outcome logic.

POST /rulebooks/
GET /rulebooks/{id}
GET /rulebooks/{id}/schema
POST /rulebooks/{id}/activate
POST /rulebooks/{id}/archive

Quick example

# Evaluate eligibility — no API key
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" },
    "include_trace": true
  }'

{
  "decision": "eligible",
  "fields_provided": 2,
  "fields_evaluated": 2,
  "trace": {
    "age_check": "PASS — age 10 is within 4–15 (Regulation 3)",
    "school_type_check": "PASS — school_type is state_funded (Section 512ZA)"
  }
}

Response codes

Code	Meaning
`200`	OK
`201`	Created (project or ruleset)
`202`	Accepted — generation queued, poll `/status`
`404`	Ruleset or project not found
`422`	Validation error — wrong field type, missing required field, invalid ruleset ID
`429`	Rate limit exceeded

422 format:

{
  "detail": [
    {
      "loc": ["body", "field_values", "child.age"],
      "msg": "Expected an integer, got str",
      "type": "type_error.integer"
    }
  ]
}

429 with rate limit headers:

HTTP/1.1 429 Too Many Requests
Retry-After: 3600
X-RateLimit-Class: generate
X-RateLimit-Limit: 200
X-RateLimit-Remaining: 0
X-RateLimit-Reset: 1753120800

{
  "detail": {
    "error": "rate_limit_exceeded",
    "reason_code": "daily_quota_exceeded",
    "message": "Quota exceeded for 'generate' (limit: 200 per rolling 24h). Upgrade your tier or wait for the window to slide.",
    "category": "generate",
    "tier": "free",
    "limit": 200
  }
}

Requests are metered per operation class over a rolling 24-hour window. Every metered response carries X-RateLimit-* headers, and GET /usage returns budget and usage across all classes without consuming quota.

For higher-level interfaces — CLI, MCP server, Python SDK — see Which interface?. Select an endpoint from the sidebar to view its full parameter schema and example responses.

Getting started (no key)

AI coding agents

Interfaces

Recipes

Authoring (invite-only)

Reference

Changelog

Base URL

Authentication

Endpoint groups

Decision

Projects (invite-only)

Rulesets

Rulebooks

Quick example

Response codes

​Base URL

​Authentication

​Endpoint groups

Decision

Projects (invite-only)

Rulesets

Rulebooks

​Quick example

​Response codes

Base URL

Authentication

Endpoint groups

Quick example

Response codes