Frequently asked.

General

What is AstroWay API?

A professional HTTP API for astrology calculations. 705 endpoints powered by Swiss Ephemeris (WASM): natal charts, synastry, progressions, directions, transits, Human Design, astrocartography, rectification, AI interpretations. All calculations run server-side — no client-side dependencies.

Who is this API for?

Developers building astrology apps (web/mobile), AI companies adding astrology features, professional astrologers with custom scripts, and researchers needing programmatic access to calculations.

How accurate are the calculations?

Swiss Ephemeris delivers planet positions accurate to ±1 arcsecond, house cusps to ±1 arcminute. Verified against Astrodienst (Astro.com), Solar Fire, Zet 9, and Kepler. Sub-arcsecond drift vs NASA JPL ephemeris and NASA 5-Millennium Eclipse Catalog.

How does AstroWay compare to Astro.com or Solar Fire?

Identical Swiss Ephemeris engine — the same one used by Solar Fire ($495 license), Kepler ($995), Astro Gold ($29.99/mo), and Astrodienst (Astro.com). Validated against NASA JPL ephemeris and Astrodienst’s official swetest reference. Sub-arcsecond drift (≤0.1″) on planetary positions, ≤1 minute on eclipses. The difference: AstroWay is a REST API starting at $5/mo, not a one-time license or desktop GUI.

Which house systems are supported?

15 systems: Placidus (default), Koch, Whole Sign, Equal, Regiomontanus, Campanus, Topocentric, Alcabitius, Morinus, Porphyrius, Vehlow, Krusinski-Pisa, Hindu Bhava, APC, and Equal from MC. Pass the appropriate code in the houseSystem parameter.

Credits and billing

How does the credit system work?

Each endpoint has a fixed credit cost (10–500), depending on calculation complexity. Simple lookup — 10, natal chart — 20, synastry — 50, rectification — 500. Full table — on the Pricing page.

Is there a free tier?

Yes. The Free plan gives 10,000 credits/month with 10 req/min. No credit card required. Enough for product evaluation and prototyping.

What happens when credits run out?

Free — requests blocked until next month (429 CREDITS_EXHAUSTED). Starter and Pro — overage kicks in: $5 or $3 per 1,000 extra credits.

Are identical requests cached?

Yes. Identical input within 5 minutes returns from cache without consuming credits. Confirmed via X-Cache: HIT header.

Can I buy credits without a subscription?

Not yet. Subscriptions give you a predictable budget and better rate limits. Pay-as-you-go is planned.

Technical

Which SDKs are available?

• MCP server ✅ shipped: npx -y @astroway/mcp — exposes all 705+ endpoints as tools for Claude Desktop, Cursor, GPT and other MCP-compatible AI agents
• TypeScript SDK ✅ shipped: npm install @astroway/sdk — full types + autocomplete from OpenAPI 3.1, retry + idempotency, Stainless-style errors
• Python SDK ✅ shipped: pip install astroway — sync Astroway + async AsyncAstroway on httpx, PEP 561 typed
• PHP SDK ✅ shipped: composer require astroway/sdk — PHP 8.1+, Guzzle 7 + PSR-18, retry middleware
• Go / Ruby / Rust 📋 planned — subscribe to release notifications on each SDK page (/en/sdk/<language>/)

The API contract is plain REST + JSON, so any HTTP client works without an SDK. Postman collection and OpenAPI 3.1 spec are publicly available.

Is there a sandbox mode?

Yes. Keys prefixed aw_test_* don’t consume credits and return the same results. Ideal for development and testing.

What are the rate limits?

Depends on your plan: Free — 10, Indie — 30, Starter — 120, Pro — 400, Business — 1,000 req/min. Exceeding returns 429 with a Retry-After header.

Is the sidereal zodiac supported?

Yes. Pass "zodiacType": "sidereal" and optionally "ayanamsaId" (default: Lahiri). Works with all endpoints.

What are the Human Design endpoints?

12 endpoints for calculating Human Design: type, strategy, authority, profile, definition, incarnation cross, channels, centers, Dream Rave, Hologenetic Profile, Penta (group dynamics), time sensitivity. Deepest HD coverage among commercial APIs.

Security and privacy

Do you store request data?

The API is stateless — birth date/time/coordinates are not retained after request processing. We only log metadata: key_id, endpoint, timestamp, latency, credits. No personal data.

Is the API GDPR-compliant?

Yes. No data retention. For EU users: no PII processing, no profiling, no cookies. The API key is bound to your account, not to end users.

Are AI interpretations safe?

AI endpoints (/interpret/*, /horoscope/*) have built-in safety guardrails: no medical, legal, or financial advice. Every response includes a disclaimer. Full audit trail for enterprise compliance.

Support

How do I get help?

Depends on your plan: Free — community, Indie — email (48h), Starter — email (24h), Pro — email (4h), Business — email + Slack (1h), Enterprise — dedicated Slack manager. Contacts — on the Contact page.

Is there an SLA?

Indie: 99% uptime. Starter and Pro: 99.9% uptime. Business: 99.95% uptime. Enterprise: custom SLA with financial guarantees.